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  #1  
Old 02-08-2018, 11:51 PM
calpik calpik is offline
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Default why groups move horizontally with powder change?

Noticed a strange thing, with some bullets/powder groups move horizontally more than vertically.

What's the reason of such behavior? (rifle is not bedded, 223rem, weatherby vanguard)
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Old 02-09-2018, 6:26 AM
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Welcome

The speed of the bullet is only one part that influences the point of impact (POI).

For example:
A 1 grain difference in a load gives a 130 fps increase in MV. That translates to a 0.2" difference in bullet drop. You're probably seeing more movement than that with less powder change.

Your group movement is not due to the change in exterior ballistics of the bullet (purely due to change in bullet drop). It's due to the barrel whipping around and the bullet exiting the barrel while the barrel is pointing in different directions. The barrel vibrations are in 2 dimensions, left/right and up/down. The trick is to find the consistently smallest group (an accuracy node), then adjust your scope to center the crosshairs within that group.

If you're shooting a lot of bullets, the barrel is also heating up and can change its bending characteristics too. That could change the point of impact.

Last edited by rsrocket1; 02-09-2018 at 6:29 AM..
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Old 02-09-2018, 6:51 AM
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Once my win mag loosened the scope mount
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Old 02-09-2018, 8:06 AM
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It could be seating depth , and or crimping .
I take apart dies after about 500 to 600 reloads and run thru sonic .
The 1st magazine [ yes I keep track ] mainly for the dies to seat in , warm up barrel and get comfortable .
FYI - I use WD-40 and the W D stands for water displacement - it is a coating [ dust magnet ] not a lubricating oil
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Old 02-09-2018, 11:53 AM
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Quote:
Originally Posted by rsrocket1 View Post
Welcome

The speed of the bullet is only one part that influences the point of impact (POI).

For example:
A 1 grain difference in a load gives a 130 fps increase in MV. That translates to a 0.2" difference in bullet drop. You're probably seeing more movement than that with less powder change.

Your group movement is not due to the change in exterior ballistics of the bullet (purely due to change in bullet drop). It's due to the barrel whipping around and the bullet exiting the barrel while the barrel is pointing in different directions. The barrel vibrations are in 2 dimensions, left/right and up/down. The trick is to find the consistently smallest group (an accuracy node), then adjust your scope to center the crosshairs within that group.

If you're shooting a lot of bullets, the barrel is also heating up and can change its bending characteristics too. That could change the point of impact.

That means that I have to look for a "node" (the powder charge/seating depth/other things when small change in a parameter does not change much. For example I see situation when 0.7gr powder load range does not make any difference in vertical and groups are good) for both horizontal and vertical? Like finding the spot, when small changes in powder/seating depth do not move group much both vertically and horizontally.

That's the first time I see that. Previous experiments were ok - group did not shift right/left much (usually right with increasing powder charge), mostly vertical.


Could it be something with rifle? It's not bedded, nothing is done with the rifle itself. Will "kitchen" bedding help? (howa 1500 action , standard barrel and boyds stock)
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Old 02-09-2018, 11:55 AM
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Quote:
Originally Posted by tonyjr View Post
It could be seating depth , and or crimping .
I take apart dies after about 500 to 600 reloads and run thru sonic .
The 1st magazine [ yes I keep track ] mainly for the dies to seat in , warm up barrel and get comfortable .
FYI - I use WD-40 and the W D stands for water displacement - it is a coating [ dust magnet ] not a lubricating oil
crimping... I have a lee precision factory crimp die and every time I use everything gets worse. I do not know how to properly control it/measure it (crimping) and do not want to waste bullets anymore.
Does it realy help? rifle is bolt action...


Seating depth can change POI? Realy? Can you please explain this a little bit?
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Old 02-09-2018, 11:57 AM
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Originally Posted by AGGRO View Post
Once my win mag loosened the scope mount
naaah... it's 223, I have some factory ammo I use to check 0 while I experiment with reloads.
scope is ok. (at least I think so)
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Old 02-09-2018, 12:17 PM
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Barrels flex in all directions when fired.
For accuracy, what you want to do is develop a load where the bullet exits the barrel timed to when the barrel is pointed straight at the target.
Usually this is done by experimenting with different bullets and powders / charges / velocities until a match-up is found.

Browning's BOSS was a threaded muzzle weight that could be adjusted to get the barrel flex to time up with whatever ammo was being used at the time.
This approach is adjusting the barrel to the ammo, rather than adjusting the ammo to the barrel.
Info on the BOSS and barrel flex:
http://www.browning.com/support/freq...tune-boss.html

The BOSS did not prove to be too popular, with most precision shooters preferring to focus on adjusting the ammo.

If your gun shoots consistently, even if the POI is different with different ammo, then bedding is probably not the issue.
You just need to find a load that consistently matches up with your barrel.
Then adjust your scope to match the POI of that load.
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Old 02-09-2018, 12:47 PM
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calpik
The pressure that pushes the bullet changes from no crimp to a heavy crimp .
The more pressure , the faster the pill should turn
Different batches of cases will crimp differently .
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Old 02-09-2018, 1:06 PM
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Originally Posted by ojisan View Post
Barrels flex in all directions when fired.
For accuracy, what you want to do is develop a load where the bullet exits the barrel timed to when the barrel is pointed straight at the target.
Usually this is done by experimenting with different bullets and powders / charges / velocities until a match-up is found.

....


You just need to find a load that consistently matches up with your barrel.
Then adjust your scope to match the POI of that load.

Does that mean: just find a charge with a smallest grouping (100-300 yards) and adjust your scope for that load?
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Old 02-09-2018, 1:07 PM
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Quote:
Originally Posted by tonyjr View Post
calpik
The pressure that pushes the bullet changes from no crimp to a heavy crimp .
The more pressure , the faster the pill should turn
Different batches of cases will crimp differently .
yes, but how to control that "no crimp to heavy crimp"
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Old 02-09-2018, 1:07 PM
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See post 28, under the heading "Tricks to loading extruded va ball powder"

A very good explanation of the phenomenon you are experiencing.

Oh and welcome to CalGuns.....
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Old 02-09-2018, 1:46 PM
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Quote:
Originally Posted by TexasJackKin View Post
See post 28, under the heading "Tricks to loading extruded va ball powder"

A very good explanation of the phenomenon you are experiencing.

Oh and welcome to CalGuns.....
thank you!



Quote:
Originally Posted by rsrocket1 View Post
The exact weight of the powder makes a big difference in how "tolerant" it is to minor changes in charge weight and velocity.

There is no "flat spot" in velocity. More powder, whether it is at a node or not will give you more velocity. What happens is that at a node, the barrel harmonics are at a peak or valley and a slight change in velocity does not change where the barrel is "pointing". This means you get a small group of shots on the target rather than a large one.

Now, i you can get the bullet to exit the barrel at exactly the same spot every time regardless of the overall charge weight, your groups will always be small, the POI will simply move around because with one charge weight, the "whipping" barrel will be pointing in one direction and with a different charge weight, it will be pointing in another direction but with each charge, it will always point in its own direction consistently.

Of course, that's impossible because as the powder burns, it doesn't burn exactly the same every shot and there will be slight statistical variations in MV even if you could charge your cartridges to 0.001g and seat the bullet to 1 mil accuracy. So the bullets will be exiting the muzzle at different times.

If you think of the muzzle vibrating like a sine wave, the barrel tip spends more time at the top and bottom of the wave and moves the fastest in the middle. If you happen to pick a charge that makes the bullet exit the muzzle in the middle of the sine wave, you will get the worst accuracy even if you could measure out your powder to the individual stick or ball. Conversely, if you could make the bullet exit at the top or bottom of the wave, the barrel might be pointing in the same direction even if you are off by 0.1g or more (or at different temperatures, different altitudes, or slightly different bullet weights or seating depths). This is what is called an "accuracy node". Unfortunately, the barrel is whipping in 2 dimensions so it's not as simple as up/down but it's coupled with left/right too.

Each barrel length has its own accuracy nodes. That's what we are trying to find when we work up loads looking for the best groups. Barrels will have nodes at multiple velocities and some will be flatter longer than others. At a node, you can vary things a little bit and the barrel will still be pointing in the same direction. That will mean slight differences in bullet weight, velocity and barrel temperature will make almost no difference in POI.

Factory ammo is usually fairly accurate in almost any barrel length not because they have a secret sauce for finding the accuracy node of every barrel ever made, it's because they can make ammo to very close tolerances. Even Federal Value Pack or PMC .223 ammo have > 1% SD spreads in velocities. We can do better but it will likely be because we found a node rather than we were able to match their consistency in making the ammo.

For true accuracy chasing, you need at least 5 shot groups and 10 chrony readings under multiple conditions. For "minute of deer" at 50-75 yards, you probably don't even need to work up loads, just find something that feels good to shoot and have at it.

That's my free advice. Remember, you get what you pay for.
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  #14  
Old 02-09-2018, 3:35 PM
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If it's a bolt rifle, forget about crimping. It's not necessary, just like it's not necessary to crimp primers for bolt guns.

My rifles are all bolt action, I hand load for the three centerfire calibers, I don't crimp bullets (or primers), and they all shoot just fine..
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Old 02-09-2018, 6:56 PM
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Quote:
Originally Posted by calpik View Post
yes, but how to control that "no crimp to heavy crimp"
Ok I will tell you how I use my FCD...
First screw die in to press unitl it just touches the shellholder... Mark the top of the FCD on the top of it at 9oclock with a sharpie...
Lower the ram with shelholder just a bit ,,, and rotate die to 3oclock position...
Lock the die loosely inplace...
Measure a loaded round at the case mouth with calipers,,, example .275...
Run the loaded round up fully into the die While you are looking down into the top of the die... Did you see the 4 slits in the top come together ???...
How close together ???
Drop ram and remeasure the the case mouth,,, as close to the bullet as possible again...
Is measurement still .275 ??.. If so tighten die (sharpie mark) to the 4oclock position and run cartridge up into die again,, and watch the 4 slits inside of the die again...
Drop ram and remeasure at casemouth again... Is measurement smaller now ?? Maybe .273 ???
Continue on this system until you get the crimp you want..
I only tapercrimp to .003 maybe,,, looking at the outside of the casemouth nearest the bullet,,, I am looking for a fine line appearing on the outside neck of my brass... This will measure .272 or so....
A heavy line is too much,,, and also while looking down into the die at the 4 slits they should barely touch... Anymore is to much and will crimp to much and damage the die and overcrimp the bullet...
It's a trial and error process,,, move slowly from the 3oclock position...
Sorry long winded but wanted to be clear...
Good shooting and ,,, Cheers....
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Old 02-09-2018, 7:38 PM
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The barrel on a good gun will only show vertical stringing as you vary the powder charge.
If you are getting horizontal it is either the shooter or the gun.
Bedding should be your first fix after the scope the rings and the base have been ruled out.
The Boss system works but it's a little bit too light. On a typical competition diameter barrel 6-11 ounces works best.
Gene Bukys won the biggest Benchrest match of the year three times using a tuner and they are gaining in popularity.
Accuracy is only found while the muzzle of the barrel is moving in a upward direction. If the muzzle is moving downward the gun won't group well.
When the barrel is moving upward the slower shots stay in the barrel longer so they exit the muzzle in a higher trajectory than the faster bullets. If they converge on the target that is when you will see best accuracy.
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Old 02-10-2018, 7:49 AM
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Quote:
Originally Posted by LynnJr View Post
The barrel on a good gun will only show vertical stringing as you vary the powder charge.
If you are getting horizontal it is either the shooter or the gun.
Bedding should be your first fix after the scope the rings and the base have been ruled out.
The Boss system works but it's a little bit too light. On a typical competition diameter barrel 6-11 ounces works best.
Gene Bukys won the biggest Benchrest match of the year three times using a tuner and they are gaining in popularity.
Accuracy is only found while the muzzle of the barrel is moving in a upward direction. If the muzzle is moving downward the gun won't group well.
When the barrel is moving upward the slower shots stay in the barrel longer so they exit the muzzle in a higher trajectory than the faster bullets. If they converge on the target that is when you will see best accuracy.
Excuse my ignorance, but how does one know which direction the barrel is moving and how does one adjust it to move in the right direction?
Can you explain to a novis or point me to a book that will get me started?
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Old 02-10-2018, 8:07 AM
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Originally Posted by nedro View Post
Excuse my ignorance, but how does one know which direction the barrel is moving and how does one adjust it to move in the right direction?
Can you explain to a novis or point me to a book that will get me started?
A calgunner's way of summing it up (another thread) -

Quote:
Originally Posted by rsrocket1 View Post
The exact weight of the powder makes a big difference in how "tolerant" it is to minor changes in charge weight and velocity.

There is no "flat spot" in velocity. More powder, whether it is at a node or not will give you more velocity. What happens is that at a node, the barrel harmonics are at a peak or valley and a slight change in velocity does not change where the barrel is "pointing". This means you get a small group of shots on the target rather than a large one.

Now, if you can get the bullet to exit the barrel at exactly the same spot every time regardless of the overall charge weight, your groups will always be small, the POI will simply move around because with one charge weight, the "whipping" barrel will be pointing in one direction and with a different charge weight, it will be pointing in another direction but with each charge, it will always point in its own direction consistently.

Of course, that's impossible because as the powder burns, it doesn't burn exactly the same every shot and there will be slight statistical variations in MV even if you could charge your cartridges to 0.001g and seat the bullet to 1 mil accuracy. So the bullets will be exiting the muzzle at different times.

If you think of the muzzle vibrating like a sine wave, the barrel tip spends more time at the top and bottom of the wave and moves the fastest in the middle. If you happen to pick a charge that makes the bullet exit the muzzle in the middle of the sine wave, you will get the worst accuracy even if you could measure out your powder to the individual stick or ball. Conversely, if you could make the bullet exit at the top or bottom of the wave, the barrel might be pointing in the same direction even if you are off by 0.1g or more (or at different temperatures, different altitudes, or slightly different bullet weights or seating depths). This is what is called an "accuracy node". Unfortunately, the barrel is whipping in 2 dimensions so it's not as simple as up/down but it's coupled with left/right too.

Each barrel length has its own accuracy nodes. That's what we are trying to find when we work up loads looking for the best groups. Barrels will have nodes at multiple velocities and some will be flatter longer than others. At a node, you can vary things a little bit and the barrel will still be pointing in the same direction. That will mean slight differences in bullet weight, velocity and barrel temperature will make almost no difference in POI.

Factory ammo is usually fairly accurate in almost any barrel length not because they have a secret sauce for finding the accuracy node of every barrel ever made, it's because they can make ammo to very close tolerances. Even Federal Value Pack or PMC .223 ammo have > 1% SD spreads in velocities. We can do better but it will likely be because we found a node rather than we were able to match their consistency in making the ammo.

For true accuracy chasing, you need at least 5 shot groups and 10 chrony readings under multiple conditions. For "minute of deer" at 50-75 yards, you probably don't even need to work up loads, just find something that feels good to shoot and have at it.

That's my free advice. Remember, you get what you pay for.
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my gun shoots better with shiny brass...plus not only does the shiny brass make me look like a pimp at the range if the sun catches it just right it blinds the guy next to me which improves my odds of winning the match.
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Old 02-10-2018, 8:15 AM
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Old 02-10-2018, 9:39 AM
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Quote:
Originally Posted by calpik View Post


Seating depth can change POI? Realy? Can you please explain this a little bit?
Yes, seating depth can make a difference. I played with this idea using a mild charge. This is the jump that the bullet makes before engaging the rifling. Some bullets prefer a longer jump and some like no jump or .005" of jump.
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Old 02-10-2018, 1:39 PM
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Originally Posted by Kwikvette View Post
A calgunner's way of summing it up (another thread) -
When I started reading what you quoted, I was thinking that, "This is not answering my question."
But it actually did a very good job of doing so.
It doesn't tell me what to do. Rather, what to look for.

When I started reloading, I was pining for a Chrono to be able to really get detailed info on my loads. So I bought a Caldwell. It is almost OK. But I have to do my calcs at a public range where the chrono has to be out where I cannot mess with it during open fire. It's always turning its self off or needing to be cycled on or off.
So its pretty much useless.
You guys are making me think real hard about getting a LabRadar.
CalGuns: Costing me money since 2014. The moment I joined up, I found out about the SSE. That cost me a cool 8 bills.
It's just been getting more and more expensive ever since.
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Old 02-10-2018, 2:07 PM
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Quote:
Originally Posted by nedro View Post
When I started reading what you quoted, I was thinking that, "This is not answering my question."
But it actually did a very good job of doing so.
It doesn't tell me what to do. Rather, what to look for.

When I started reloading, I was pining for a Chrono to be able to really get detailed info on my loads. So I bought a Caldwell. It is almost OK. But I have to do my calcs at a public range where the chrono has to be out where I cannot mess with it during open fire. It's always turning its self off or needing to be cycled on or off.
So its pretty much useless.
You guys are making me think real hard about getting a LabRadar.
CalGuns: Costing me money since 2014. The moment I joined up, I found out about the SSE. That cost me a cool 8 bills.
It's just been getting more and more expensive ever since.
My dad has cost me more than anyone in that, he got me into firearms

The forum (and a friend of mine) encouraged me to reload which is another hobby in itself.

In my latest load development with H1000 and .300wm, I found an accuracy node that yielded a > .5" group with no vertical spread.

I'll shoot the same loaded cartridge next week, and load a few more at different seating depths to see if my horizontal tightens up.
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my gun shoots better with shiny brass...plus not only does the shiny brass make me look like a pimp at the range if the sun catches it just right it blinds the guy next to me which improves my odds of winning the match.
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Old 02-10-2018, 4:08 PM
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Quote:
Bedding should be your first fix after the scope the rings and the base have been ruled out.
it seems that it's time to bed the rifle. I already glued the rail.


Quote:
Originally Posted by LynnJr View Post
The barrel on a good gun will only show vertical stringing as you vary the powder charge.
If you are getting horizontal it is either the shooter or the gun.
Bedding should be your first fix after the scope the rings and the base have been ruled out.
Accuracy is only found while the muzzle of the barrel is moving in a upward direction. If the muzzle is moving downward the gun won't group well.
When the barrel is moving upward the slower shots stay in the barrel longer so they exit the muzzle in a higher trajectory than the faster bullets. If they converge on the target that is when you will see best accuracy.
I'm not sure if it's a right term "stringing", because groups are relatively ok, they just move right/left, instead of up/down. And that's only for bullet/powder combination, other bullets/powders behave differently.


If it's a gun (let's skip "shooter" at this moment ) , what could be a reason of such behavior? is it possible to fix at home?
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Old 02-10-2018, 4:15 PM
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Originally Posted by NiMiK View Post
Yes, seating depth can make a difference. I played with this idea using a mild charge. This is the jump that the bullet makes before engaging the rifling. Some bullets prefer a longer jump and some like no jump or .005" of jump.
grouping changes, but the poi is the same?


(is it possible to seat bullet to the same depth with lee dead bullet seater? or I should upgrade? NOT the runout (tools for measuring/controlling this are way too expensive for what I do right now), but the depth
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Old 02-10-2018, 5:41 PM
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Barrel flex, with more or less powder it would change poi. Question is, why to the side? Is there a muzzle break on your barrel.

Edit: on second thought it is probably just a harmonic caused by a poorly fitting stock.
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Old 02-10-2018, 6:30 PM
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Originally Posted by calpik View Post
grouping changes, but the poi is the same?


(is it possible to seat bullet to the same depth with lee dead bullet seater? or I should upgrade? NOT the runout (tools for measuring/controlling this are way too expensive for what I do right now), but the depth
POI was the same since I was only at 100 yards and was already zeroed with 175gr FGMM. Group 4's shift was caused by me pressing too hard on the cheekrest and seeing my heartbeat through the reticle.
Not sure what tools you currently have or if you're measuring COAL or CBTO. I measure mine based on CBTO. You can try a Hornady comparator kit as it's nowhere near the cost of competition dies.
Best tip I was given by a BR shooter was, save your fired brass and make a modified case so you can get a baseline of where your bullet starts engaging the rifling.
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Old 02-10-2018, 7:03 PM
LynnJr LynnJr is offline
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Nedro
When you are working up a load and your shots don't have the exact same velocity the faster bullets exit the barrel first.
If the muzzle of the barrel is climbing the slower bullets which are in the barrel longer are launched at a higher angle.
For those two bullets to group the bullet that started out higher with the lower velocity will converge or cross paths with the faster bullet at some point along its flight path.

If the muzzle of the barrel is in a downward direction the slower bullet would still stay in the barrel longer.
The faster bullet would exit sooner and the two paths would never cross at any distance.

I will post a picture that will hopefully show what I am referring too.
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Old 02-10-2018, 7:32 PM
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CalPik
Put your index finder on the forend of the stock and the barrel at the same time. Now loosen up one action screw and see if you feel any movement between the barrel and the stock. If you can the action needs to be bedded.
Repeat with each screw.
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Old 02-11-2018, 12:20 PM
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Quote:
Originally Posted by KahrMan View Post
Barrel flex, with more or less powder it would change poi. Question is, why to the side? Is there a muzzle break on your barrel.

Edit: on second thought it is probably just a harmonic caused by a poorly fitting stock.
no , there is no muzzle brake..

ok, second voice for rifle bedding (and yes, it looks like gap in a barrel channel on a left side became smaller than it was before..)
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Old 02-11-2018, 12:28 PM
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Quote:
Originally Posted by NiMiK View Post
POI was the same since I was only at 100 yards and was already zeroed with 175gr FGMM. Group 4's shift was caused by me pressing too hard on the cheekrest and seeing my heartbeat through the reticle.
Not sure what tools you currently have or if you're measuring COAL or CBTO. I measure mine based on CBTO. You can try a Hornady comparator kit as it's nowhere near the cost of competition dies.
Best tip I was given by a BR shooter was, save your fired brass and make a modified case so you can get a baseline of where your bullet starts engaging the rifling.

yes, that's what I do.
I have hornady comparator, calipers (electronic) and several "blanks" with special bullet seating depth.

My question was about the seating process itself. Every time I push a bullet (lee hand press and lee dead bullet seating die) I see different seating depth. I do rotate cartridges while i'm pushing bullet (they do not sit straight, I pull back a little bit, rotate cartridge and push it back and they look better).

Q1: how to seat bullets properly? OR What's the reason of different seating depth (it can differ up to 3-4 thousands of inch)
Q2: I feel different resistance while seating a bullet. What's the reason of that? - I measured case necks after sizing (lee collect sizer) , they all are around the same value, may be 1\2 of thousands of inch difference. And bullets which are seated easily usually sit deeper...
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Old 02-11-2018, 12:31 PM
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Lynn jr got it right . It is called barrel dwell. The longer the projectile is within barrel recoil will determine a higher flight evel from barrel. The difference comes downrange where velocity and bullet weight come into play= trajectory.
A lot of people are clueless on this.
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Old 02-11-2018, 12:31 PM
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Quote:
Originally Posted by LynnJr View Post
CalPik
Put your index finder on the forend of the stock and the barrel at the same time. Now loosen up one action screw and see if you feel any movement between the barrel and the stock. If you can the action needs to be bedded.
Repeat with each screw.
yep. I noticed that during rifle assemble/disassemble procedure: I hold rifle with one hand (forehand and barrel) and work on a screw and I can feel that barrel moves.
front screw relatively ok, but when I work on a back screw - I definitely _see_ the movement.


so... third voice for bedding...

have bunch of questions here. Should I start a new topic in a proper subforum?
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Old 02-11-2018, 1:05 PM
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Quote:
Originally Posted by LynnJr View Post

When you are working up a load and your shots don't have the exact same velocity the faster bullets exit the barrel first.
If the muzzle of the barrel is climbing the slower bullets which are in the barrel longer are launched at a higher angle.
For those two bullets to group the bullet that started out higher with the lower velocity will converge or cross paths with the faster bullet at some point along its flight path.

If the muzzle of the barrel is in a downward direction the slower bullet would still stay in the barrel longer.
The faster bullet would exit sooner and the two paths would never cross at any distance.

I will post a picture that will hopefully show what I am referring too.

yes, I understand the process of "tuning" charge for a barrel movement. I just did not know how to eliminate/minimize horizontal part in that equation. (If it's possible at all... without rebarreling and such things)




another question about the process itself:
I want to move shoulders back a little bit. because after several shots bolt is very stiff and hard to close.
I tried lee FL die and it works, BUT

Q1: some cases do not size properly, most of them are sized and some just do not want to become smaller (they're 1-1.5 thousands of inch bigger). even if I push them 2-3 times through the die, rotating each time. What's the problem with such cases? is there anyway to fix that?

Q2: each time I use lee FL die, neck grows like crazy and I have to trim 4-6 thousands of an inch. I don't like that (i'd like to avoid trimming procedure for 2-3 reloads without having a risk to blow off my head because neck is too long and stuck in rifling and pressure went through the roof).
So, the question is very simple: redding body sizing die or redding bushing FL die? Will I get any advantage with bushings in future (i'm not going to use it at this moment) if I buy another factory rifle and if i'm not turning necks (as I understand eventually I'll do that... can not stop with that reloading crap... )
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Old 02-11-2018, 1:29 PM
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It's very likely your press is "springing" make sure your shell holder contacts the die, under the force of re-sizing, not just when there is no case present.
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Old 02-11-2018, 4:28 PM
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Quote:
Originally Posted by calpik View Post
no , there is no muzzle brake..

ok, second voice for rifle bedding (and yes, it looks like gap in a barrel channel on a left side became smaller than it was before..)
Ther are also devices which attach t a barrel and can be moved to tune out the harmonic vibration. However before doing something like that, it is sounding like the first thing t do would be bedding the stock and making sure you barrel really is floating free.
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Old 02-12-2018, 2:18 AM
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Default It is the Shooter or the gun or the ammo.

It's almost impossible to diagnosis the problem when the consistency of the ammo is changing. So let's get the ammo factor out of the way.

It is a .223, right, fine. Buy a couple hundred of all same new factory match quality cartridges, shoot a dozen 5 shot groups under the same conditions. Then shoot another batch of group shooting next day or next range session... Compare...Get some solid results to establish baseline. Remember, we haven't mentioned anything yet about glass or mounts.

Horizontal stringing could be the wind. Sling tension sends rounds off horizontally. SNAFU bedding equals all shots all the time are also SNAFU. Vertical stringing usually means weak position or change in bullet seating depth. Futz-up groups often occur immediately after making scope adjustments. Even some high priced rifle scopes don't track worth beans.

When experienced pistol shooters start stringing horizontal I tell them to go back to using one eye. At `5 yards, draw a 2 inch by 5 inch straight up & down line on a blank target. You see the results in about 1 minute or less. Rifle shooting might be different, might.

Since the human factor is the biggest factor...coupled with Reloading...my vote it's the nutt behind the butt. Later on we can discuss the affects of light on your sights.

Last edited by hambam105; 02-12-2018 at 2:34 AM..
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Old 02-12-2018, 9:13 AM
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hambam105
I agree - factory ammo is the place to start .
It can sort out the ammo , gun or shooter .
For me , it was for hunting , but those days are gone .
I would use 2 of the lawn chair cushions and a rifle bench rest .
Once everything was the small -warmed rifle , scope , my butt
then it was time for ladder test - 5 groups of 5 or 7 .
Elimate one variable at a time .
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Old 02-12-2018, 9:43 AM
LynnJr LynnJr is offline
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Quote:
Originally Posted by calpik View Post
yes, I understand the process of "tuning" charge for a barrel movement. I just did not know how to eliminate/minimize horizontal part in that equation. (If it's possible at all... without rebarreling and such things)




another question about the process itself:
I want to move shoulders back a little bit. because after several shots bolt is very stiff and hard to close.
I tried lee FL die and it works, BUT

Q1: some cases do not size properly, most of them are sized and some just do not want to become smaller (they're 1-1.5 thousands of inch bigger). even if I push them 2-3 times through the die, rotating each time. What's the problem with such cases? is there anyway to fix that?

Q2: each time I use lee FL die, neck grows like crazy and I have to trim 4-6 thousands of an inch. I don't like that (i'd like to avoid trimming procedure for 2-3 reloads without having a risk to blow off my head because neck is too long and stuck in rifling and pressure went through the roof).
So, the question is very simple: redding body sizing die or redding bushing FL die? Will I get any advantage with bushings in future (i'm not going to use it at this moment) if I buy another factory rifle and if i'm not turning necks (as I understand eventually I'll do that... can not stop with that reloading crap... )

When you fire your rifle the brass expands to fill the chamber so it gets shorter in length. This happens because the neck gets pulled rearward to fill the shoulder area of the chamber.
When you full length size the brass you squeeze the entire body of the case and the shoulder area so the brass gets longer.
If you need to trim your brass alot the dies are working the brass too much for the size of your chamber and this will shorten the amount of times you can reload that brass before you get casehead separations.
Tight brass on chamberings means your not getting the shoulder bumped back enough. Try going further with the die to see if that works.
If it doesn't take the shellholder and run it over a piece of 80 grit wet/dry sandpaper on a flat surface in a figure 8 pattern. This will allow you to size the brass more without having to change your die.
Use a Sharpie to coat the surface of the shellholder to make sure you are sanding it evenly.
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Old 02-12-2018, 1:27 PM
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Quote:
Use a Sharpie to coat the surface of the shellholder to make sure you are sanding it evenly.
this tip is good, will check that. as I understand I check for "squareness" with this hint.


Quote:
Originally Posted by LynnJr View Post
When you fire your rifle the brass expands to fill the chamber so it gets shorter in length. This happens because the neck gets pulled rearward to fill the shoulder area of the chamber.
When you full length size the brass you squeeze the entire body of the case and the shoulder area so the brass gets longer.
If you need to trim your brass alot the dies are working the brass too much for the size of your chamber and this will shorten the amount of times you can reload that brass before you get casehead separations.
Tight brass on chamberings means your not getting the shoulder bumped back enough. Try going further with the die to see if that works.
If it doesn't take the shellholder and run it over a piece of 80 grit wet/dry sandpaper on a flat surface in a figure 8 pattern. This will allow you to size the brass more without having to change your die.
I understand the process of sizing. What I don't understand is why 1 case is sized, but another one is not (1-1.5thousands longer).
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Old 02-12-2018, 1:42 PM
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Quote:
Originally Posted by hambam105 View Post
It's almost impossible to diagnosis the problem when the consistency of the ammo is changing. So let's get the ammo factor out of the way.

It is a .223, right, fine. Buy a couple hundred of all same new factory match quality cartridges, shoot a dozen 5 shot groups under the same conditions. Then shoot another batch of group shooting next day or next range session... Compare...Get some solid results to establish baseline. Remember, we haven't mentioned anything yet about glass or mounts.

Horizontal stringing could be the wind. Sling tension sends rounds off horizontally. SNAFU bedding equals all shots all the time are also SNAFU. Vertical stringing usually means weak position or change in bullet seating depth. Futz-up groups often occur immediately after making scope adjustments. Even some high priced rifle scopes don't track worth beans.

When experienced pistol shooters start stringing horizontal I tell them to go back to using one eye. At `5 yards, draw a 2 inch by 5 inch straight up & down line on a blank target. You see the results in about 1 minute or less. Rifle shooting might be different, might.

Since the human factor is the biggest factor...coupled with Reloading...my vote it's the nutt behind the butt. Later on we can discuss the affects of light on your sights.

as I said, there is no stringing. Bullets group OK (for me at least), but with different powder charge group moves horizontally, not vertically. And was looking for a reason for that and how to fix that.

2 pictures with marking. (100yards and 300 yards)
you can clearly see shooter errors and at the same moment POI moves horizontally.

difference between loads 0.2gr
Attached Images
File Type: jpg Untitled.jpg (18.2 KB, 21 views)
File Type: jpg Untitled.2.jpg (7.9 KB, 17 views)

Last edited by calpik; 02-12-2018 at 1:43 PM.. Reason: added notes
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