PDA

View Full Version : **Update** Is this a normal windage adjustment to zero a 20" A4 type rifle? Pics


missiontrails
06-01-2011, 11:48 AM
I just zeroed a rifle today, and it just seemed that it required a ton of adjustment. I had to drop the FSP down about 3/16", no big deal there. The amount of windage adjustment seemed excessive, considering the FSB does NOT look canted. Looking for Diesel and some other "Milspec" guys to chime in. I used the 25 Meter M16A2 zeroing target for a 300m battle zero.

http://i1220.photobucket.com/albums/dd451/dehlers1/23304089.jpg
http://i1220.photobucket.com/albums/dd451/dehlers1/d781a065.jpg
http://i1220.photobucket.com/albums/dd451/dehlers1/fbe2d1ed.jpg

dieselpower
06-01-2011, 11:53 AM
6/3 and 20" I'd look at getting a NM carry handle for a 20". It may not be the FSB, it might be the carry handle or the upper.

I have seen worse that was usable with Kentucky windage.

missiontrails
06-01-2011, 11:55 AM
6/3 and 20" I'd look at getting a NM carry handle for a 20". It may not be the FSB, it might be the carry handle or the upper.

I have seen worse that was usable with Kentucky windage.

This is a CMMG handle, sitting on a factory built CMMG upper... Ya, I'm trying to think about why or what would cause the need for that much adjustment.

jimmykan
06-01-2011, 12:02 PM
I don't know the military's specified allowable range for windage zero, in what manual would you find that?

See if you can borrow another rear sight from another trusted manufacturer, like a LMT, Midwest, or Troy, and compare zero settings.

HeHateMe
06-01-2011, 12:03 PM
I had that happen on my CMMG upper. I tried a LMT and Bushmaster rear sight with a result like yours. Turns out my FSB was canted. Contact CMMG, they picked up the shipping back to them for repairs.

Droppin Deuces
06-01-2011, 12:04 PM
Well, for starters, just looking at the pic, it looks like your sight housing is sitting a little off center.

dieselpower
06-01-2011, 12:04 PM
Well CMMG isn't known for their match grade stuff. They are good and I think that is good. I would expect better from a A2 upper, but once you add in rails, carry handles, stock parts (non-NM) you get some windage.

Grab another BUIS and see what it zeros at. If they both zero around the same place, its the barrel or the FSB. You could re-position the barrel in the upper to compensate for that right windage. Just watch the torque and how the barrel tab sits in the upper slot.

missiontrails
06-01-2011, 12:10 PM
Well, for starters, just looking at the pic, it looks like your sight housing is sitting a little off center.

Every one I have ever owned has looked like that... I have a take-off from a Colt carbine.... it looks the same. My Colt Sporter in the early 90's was also like that.

Droppin Deuces
06-01-2011, 12:14 PM
Some more than others, I guess. Both of the ones I have(also Colt) are almost perfectly centered, and on both I have to add 2-3 clicks left when sighting.

Maybe you need to try some Wolf ammo:ninja:

missiontrails
06-01-2011, 12:19 PM
Some more than others, I guess. Both of the ones I have(also Colt) are almost perfectly centered, and on both I have to add 2-3 clicks left when sighting.

Maybe you need to try some Wolf ammo:ninja:

http://i1220.photobucket.com/albums/dd451/dehlers1/3c7529db.jpg

motorwerks
06-01-2011, 12:22 PM
I've never had one that bad. My bushmaster A2 was spot on with mechanical zero.

dieselpower
06-01-2011, 12:27 PM
well I just re-read the Mil-spec on acceptable zeros and the FM23-9 has this to say on it...
CONCEPT OF ZEROING
The purpose of battle sight zeroing is to align the fire control system (sights) with the rifle barrel, considering
the given ammunition ballistics. When this is accomplished correctly, the fire control and point of aim are point
of impact at a standard battlesight zero range such as 250 (300) meters.
When a rifle is zeroed, the sights are adjusted so that bullet strike is the same as point of aim at some given
range. A battlesight zero (250 meters, M16Al; 300 meters, M16A2) is the sight setting that provides the highest
hit probability for most combat targets with minimum adjustment to the aiming point.
When standard zeroing procedures are followed, a rifle that is properly zeroed for one soldier is close to the zero
for another soldier. When a straight line is drawn from target center to the tip of the front sight post and through
the center of the rear aperture, it makes little difference whose eye is looking along this line. There are many
subtle factors that result in differences among individual zeros; however, the similarity of individual zeros
should be emphasized instead of the differences.
Most firers can fire with the same zeroed rifle if they are properly applying marksmanship fundamentals. If a
soldier is having difficulty zeroing and the problem cannot be diagnosed, having a good firer zero the rifle could
find the problem. When a soldier must fire another soldier's rifle without opportunity to verify the zero by firing
- for example, picking up another man's rifle on the battlefield - it is closer to actual zero if the rifle sights are left
unchanged. This information is useful in deciding initial sight settings and recording of zeros. All rifles in the
arms room, even those not assigned, should have their sights aligned (zeroed) for battlesight zero.
There is no relationship between the specific sight setting a soldier uses on one rifle (his zero) to the sight setting
he needs on another rifle. For example, a soldier could be required to move the rear sight of his assigned rifle 10
clicks left of center for zero, and the next rifle he is assigned could be adjusted 10 clicks right of center for zero.
This is due to the inherent variability from rifle to rifle, which makes it essential that each soldier is assigned a
permanent rifle on which all marksmanship training is conducted. Therefore, all newly assigned personnel
should be required to fire their rifle for zero as soon as possible after assignment to the unit. The same rule must
apply anytime a soldier is assigned a new rifle, a rifle is returned from DS or GS maintenance, or the zero is in
question.

Thats about what I have always gone off. Each rifle is its own. I have seen few dead-nuts centerline at 25 yards, most require at least some left or right movement.

If 3 shots hit in a 4cm circle at 25 yards...thats the rifles zero. You can adjust that by removing and re-torquing the barrel.

missiontrails
06-01-2011, 12:29 PM
I've never had one that bad. My bushmaster A2 was spot on with mechanical zero.

At mechanical zero, this thing was 5" to the left and 6" low at 25 yards. I just looked at the FSB a hundred different ways.... it could not be any more straight. Now, after the funky adjustments, all rounds are within a quarter size grouping.

dieselpower
06-01-2011, 12:32 PM
I've never had one that bad. My bushmaster A2 was spot on with mechanical zero.

thats an A2... A2s are known to be a bit more accurate than A3s and A4s with detachable carry handles. any time you get a removable BUIS, there will be error.

GSequoia
06-01-2011, 12:32 PM
Well, for starters, just looking at the pic, it looks like your sight housing is sitting a little off center.

[SIZE="4"]http://i1220.photobucket.com/albums/dd451/dehlers1/d781a065.jpg

That's from the detent spring that preloads tension on the rear sight.

missiontrails
06-01-2011, 12:41 PM
Ya, I would say that I'm within 10 clicks...... How many total clicks of adjustment does a standard A2 sight have from center to the very end of the markings? The good news is that is hits accurately now, and I have used only HALF of the adjustment range to the right side. Good enough for me.

247Nino
06-01-2011, 12:47 PM
It looks like a lot. Try it with another carry handle. Check your upper for barrel nut torque. If it shoots consistent then don't worry about it.

dieselpower
06-01-2011, 1:05 PM
Ya, I would say that I'm within 10 clicks...... How many total clicks of adjustment does a standard A2 sight have from center to the very end of the markings? The good news is that is hits accurately now, and I have used only HALF of the adjustment range to the right side. Good enough for me.

Its depends on the clicks themselves. They are either 1/4 or 1/2 MOA.

Mine has 10 clicks between hash marks and each hash mark is 1/4 MOA
I have 2.5 has marks, just like yours does. BUT you could have 1/2 hash marks meaning your 11 clicks is equal to my 22 clicks.

My current zero is 16 clicks right. I just confirmed it by counting clicks to center. On yours that would be 1 click right of the longer line...I dont know how many clicks you have between lines.

This kind of stuff gets messed up all the time. NM parts mixed with A2 parts mixed with A3 detachable parts. Thats why you can buy a Colt carry handle for $50 or an ArmaLite for $180.

I believe I have an A3 with a mis-matched A2 windage drum. I have seen many NM with A3 drums..which would send me screaming to a customer service rep...LOL I pay $180 for a freaking carry handle, you better get all the parts correct.

I think you are fine. Like I said, I have seen worse. Its rare to adjust for windage if you are not a NM shooter.

motorwerks
06-01-2011, 3:50 PM
thats an A2... A2s are known to be a bit more accurate than A3s and A4s with detachable carry handles. any time you get a removable BUIS, there will be error.

good point, hadnt really thought about that.

missiontrails
06-02-2011, 9:18 AM
Ok, now I'm very confused. I just used a laser bore sight, and I had to basically move the windage back to the center to view the dot on the wall @ 20 yards away to see it dead center over the FSP... WTF? Now, I will say that the indoor range lighting was terrible yesterday, and I had a real hard time seeing the front sight centered in the rear peep hole. I'm wondering if the lack of contrast and lighting in that place caused issues?? I mean literally, the rear sight was blurry and dark, and seeing the inside edges of the hole was near impossible....

missiontrails
06-02-2011, 9:40 AM
I have a $90 CMMG carry handle. The FSB is dead nuts.... I hit I with a laser centered over the receiver flat top. I really think I might have been the lighting, and what I "thought" I was looking at through the rear sight was not really was I seeing. Ya, 300m zero is out. I'm going to zero at 50 with the rear elevation set at 6/3 (the bottom), and readjust the front post as necessary. A laser beaming through my barrel should be close to the direction the bullet with travel from a windage standpoint. My rear is almost centered again (3 clicks right), and the laser dot sits dead nuts center over the FSP when looking through the unmarked smaller peep.

ir0nclash86
06-02-2011, 10:16 AM
The first thing I thought of was it could just be your cheek weld.

mif_slim
06-02-2011, 10:21 AM
Some more than others, I guess. Both of the ones I have(also Colt) are almost perfectly centered, and on both I have to add 2-3 clicks left when sighting.

Maybe you need to try some Wolf ammo:ninja:

First off I didnt get it...then I looked at the quote picture under this statement and understood why.

LMBO!

Sorry OP, anyways...check your front sight if its canted.

POLICESTATE
06-02-2011, 10:23 AM
Mine is like that, i don't worry about it.

dieselpower
06-02-2011, 11:10 AM
I have had this issue a lot, and this is what I deduced it to:

1) Off center FSB. This can happen from the factory -- the FSB is slid onto the barrel, then drilled together, and then the pins put in.
2) The index pin is slightly off to one side in the slot inside the receiver. Some receivers may have index holes out of spec.
3) You have a cheap carry handle.
4) This is what I had: The manufacturer does not clamp or otherwise secure the barrel and receiver when they torque it, which twists the barrel in the direction of rotation.

And 5) Don't use the 300m zero. Use the IBZ or RIBZ. Seriously -- otherwise you'll baffle yourself why you can't hit the gongs at 100yds -- because you're 6" high!

LOL... dude, if you don't understand why you can't hit a gong at 100 yards its time to go back to airsoft.

the 25m zero is fine when you understand your aiming device and how to present to a target.

the ibz is good stuff, don't get me wrong, but your comment is along the lines of, "try off road racing in that Mustang then tell me how fast you can go?" I wouldn't expect my Mustang to win a 4X4 race and i would be a complete idiot to try.

I have a 25m zero with a 4MOA dot. I will hit a gong 100 yards from me 1 MOA above my dot...why? Because the dot = 4" wide at 100 yards. My trajectory tells me my arc is between 4" and 6" high which is the size of my dot above it... think of it as a "figure 8", with my POA the bottom 0, and my POI is the top 0.

the highest hold under is about 200ish and my POA is still a "figure 8"...why? because my 4MOA dot is now 8" wide and my POI will again be the top circle of the figure 8.

As the range increase the top circle of the "figure 8", POA/POI grouping gets smaller until I get to 375 yards. At all times my POA/MOA and POI maintain a constant ratio helping me hit my target and also allowing me to see my hits as they are above my POA. You can "walk" fire into a target.

I actually just made a little diagram on this the other day. Its a training aid for those wishing to visualize the different zeroing. If you want to see it, just ask and I will post it up. Its not 100% accurate, but gets the job done as far as explaining the POA/POI/MOA ratio.

a308garand
06-02-2011, 11:18 AM
Leave it as is and try shooting it at actual distance of 100 or more yards to get better idea of where it needs to be. You may need further adjustment of the windage or it may center up, gonna have to give it a go to see.

All things being equal, to get this carry handle sight windage centered up:

1- Remount the carry handle. With the screws loose, put the handle in place and press it forward while evenly tightening the mounting knobs. This will ensure it is sitting square on the receiver and not canted.

2- Re-set the barrel. Maybe even need to shim one side of the barrel index pin to get the barrel mounted at its true top dead center for that upper receiver and sights.

vmwerks
06-02-2011, 11:21 AM
LOL... dude, if you don't understand why you can't hit a gong at 100 yards its time to go back to airsoft.

Dieselpower - beginning your post with this line kills your message. The rest of the post has good info so why kill the message by being a poor messenger... just a thought, thank you for info. I'm going out with my 20" A2 replica soon and will take it to heart.

dieselpower
06-02-2011, 11:28 AM
Dieselpower - beginning your post with this line kills your message. The rest of the post has good info so why kill the message by being a poor messenger... just a thought, thank you for info. I'm going out with my 20" A2 replica soon and will take it to heart.

people have such thin dam skin... So when the guy told us we were wrong to have a 25m zero and we can not figure out why we were 6" off from a 100 yard target that is fine?

are you freaking kidding me??????????

don't expect me to NOT to slap you, when you slap me.

99.9% of the fights I get into on these forums is from jackwagons who don't think anything of slapping a guys post (or choices), but freak out when they get treated the same way.

Most of the old timers here are so used to treating people like shiat, that when I treat them like shiat they freak out.

In any event I wasn't telling him, I was telling ANYONE who is asuch a freaking idiot that they can not figure out why their shots are high to give up guns...it wasnt directed directly at the quoted person...but he did fire the first shot.

missiontrails
06-02-2011, 12:26 PM
First off I didnt get it...then I looked at the quote picture under this statement and understood why.

LMBO!

Sorry OP, anyways...check your front sight if its canted.

Like I said TWICE.. the front sight is perfect, 0 can't.... none... nada.

bwiese
06-02-2011, 12:30 PM
I had that happen on my CMMG upper. I tried a LMT and Bushmaster rear sight with a result like yours. Turns out my FSB was canted. Contact CMMG, they picked up the shipping back to them for repairs.


IIRC, Bushmaster went thru this in late 90s with overtorqued bbls resulting in front sight canting.

IIRC again, it appears milspec is to allow +/- up to 13 clicks to get zero at 100M (yds?)

Also, I will note that you seem to have a *carbine* carry handle (sight) on your 20" *rifle*.
A rifle carry handle/sight should have the drum go to 8/3.

distshooter
06-02-2011, 12:46 PM
This is a common problem with the AR platform. The gas block with front sight was not indexed properly in relation to the barrel extension when the taper pin holes (gas block to barrel) were reamed. If you lay a machinist's square on top of the receiver rail and sight down the barrel, your will likely notice the front sight is visibly canted to one side.

Solution: Remove front sight/gas block assembly. Enlarge taper pin holes in the barrel ONLY with emphasis on removing material to provide pin clearance in the appropriate direction to straighten the sight assembly. Using a suitably sized drill bit in power tool works well along with jewelers files.

The hole for the gas port in the front sight/gas block was drilled from the bottom of the assembly. Therefore, there is a hole in the bottom of the gas block. You will need to remove the forward sling swivel and roll pin to access this hole. The bottom hole should already be threaded. If not, simply use a TAP and thread it to 10-32. Insert a 10-32 x 3/16” setscrew in the bottom hole to clamp the front sight assembly to the barrel. Use appropriate sized drill bit in place of the sling swivel roll pin to verify clearance between the sling swivel and the setscrew. You may need to trim the screw to provide clearance for the swivel to rotate. Assemble front sight/barrel assembly with clean surfaces. Use acetone.

Zero rear sight. Take gun to range and zero at 100yd’s. Shoot group. Loosen the setscrew and tap the front sight assembly in the opposite direction of which you want your impact to go. (if you want your impact to move to the left, drift the front sight to the right). A small rubber mallet makes fine adjustment easier using small taps. You will be able to get within 0-3 clicks of dead center. Tighten setscrew and apply red high–strength threadlocker such as Permatex or Loctite to the barrel/front sight interface. These are low viscosity compounds and will flow into the tight joint. It doesn’t take allot, just a couple drops on each joint will do. Allow the compound to cure before reinstalling the sling swivel roll pin.

Try not to get compound on the setscrew as the strength of these compounds are phenomenal. You will need to heat the assembly to disassemble but there should be no need to ever take it apart as they are now a ‘trued’ assembly. In the Marines our match M16’s were all setup in this manner except we didn’t use the single clamping setscrew but four opposing screws bearing on machined flats on the bottom of the barrel.

This is pretty straight forward and should be no problem for anyone with basic tool skills. If you need help, I am in the Bay Area and can assist you.

distshooter

missiontrails
06-02-2011, 1:00 PM
IIRC, Bushmaster went thru this in late 90s with overtorqued bbls resulting in front sight canting.

IIRC again, it appears milspec is to allow +/- up to 13 clicks to get zero at 100M (yds?)

Also, I will note that you seem to have a *carbine* carry handle (sight) on your 20" *rifle*.
A rifle carry handle/sight should have the drum go to 8/3.

Actually, all removable handles are 6/3..... A2 uppers without removable are 8/3. And again, the front sight is for sure not canted.

missiontrails
06-02-2011, 1:09 PM
This is a common problem with the AR platform. The gas block with front sight was not indexed properly in relation to the barrel extension when the taper pin holes (gas block to barrel) were reamed. If you lay a machinist's square on top of the receiver rail and sight down the barrel, your will likely notice the front sight is visibly canted to one side.

Solution: Remove front sight/gas block assembly. Enlarge taper pin holes in the barrel ONLY with emphasis on removing material to provide pin clearance in the appropriate direction to straighten the sight assembly. Using a suitably sized drill bit in power tool works well along with jewelers files.

The hole for the gas port in the front sight/gas block was drilled from the bottom of the assembly. Therefore, there is a hole in the bottom of the gas block. You will need to remove the forward sling swivel and roll pin to access this hole. The bottom hole should already be threaded. If not, simply use a TAP and thread it to 10-32. Insert a 10-32 x 3/16” setscrew in the bottom hole to clamp the front sight assembly to the barrel. Use appropriate sized drill bit in place of the sling swivel roll pin to verify clearance between the sling swivel and the setscrew. You may need to trim the screw to provide clearance for the swivel to rotate. Assemble front sight/barrel assembly with clean surfaces. Use acetone.

Zero rear sight. Take gun to range and zero at 100yd’s. Shoot group. Loosen the setscrew and tap the front sight assembly in the opposite direction of which you want your impact to go. (if you want your impact to move to the left, drift the front sight to the right). A small rubber mallet makes fine adjustment easier using small taps. You will be able to get within 0-3 clicks of dead center. Tighten setscrew and apply red high–strength threadlocker such as Permatex or Loctite to the barrel/front sight interface. These are low viscosity compounds and will flow into the tight joint. It doesn’t take allot, just a couple drops on each joint will do. Allow the compound to cure before reinstalling the sling swivel roll pin.

Try not to get compound on the setscrew as the strength of these compounds are phenomenal. You will need to heat the assembly to disassemble but there should be no need to ever take it apart as they are now a ‘trued’ assembly. In the Marines our match M16’s were all setup in this manner except we didn’t use the single clamping setscrew but four opposing screws bearing on machined flats on the bottom of the barrel.

This is pretty straight forward and should be no problem for anyone with basic tool skills. If you need help, I am in the Bay Area and can assist you.

distshooter

My front sight is indexed correctly...... it's not canted.

dieselpower
06-02-2011, 1:10 PM
Actually, all removable handles are 6/3..... A2 uppers without removable are 8/3. And again, the front sight is for sure not canted.

the hoods on a NM and A2 and M4 are all different and the drums are different as well. I have a pic I will look for. I think I have seen 8/3 on a detachable which is why I replied the way I did in my first post. I'll post in a minute or two. I am not familiar with A4s and their aftermarket items any more...

ok, found them and uploaded to photobucket.

These pics were all taken from a thread at AR15.com on the troubles with A2 / carry handles.

this is a pic of the three hoods out there. Nation Match, A2, and Flat top (M4)
http://i655.photobucket.com/albums/uu272/Wiringguy/BUISwheels.jpg

this is the possible drums you could have (not showing a china made crap drum)
http://i655.photobucket.com/albums/uu272/Wiringguy/Elevation_Wheel_Comparison.jpg

This is one of the two detachable deck height on a carry handle (again forget chna crap). I added the red lines to show what was different.
http://i655.photobucket.com/albums/uu272/Wiringguy/CHcom-2.jpg

and of course the FSBs (again, there are also cheap made in china ones not even close to real specs)
http://i655.photobucket.com/albums/uu272/Wiringguy/F20front20sight20base2001.jpg

You can see how easy it is for a manufacture to mix all these up (bar the Fmarked front base) and how your zero would depend on those parts working together.

it is also possible to get different twist threads on the windage screw, which will cause each click to vary in adjustment in relation to the hash marks. I have yet to get a pic of each of those different screws, I just know they exist.

missiontrails
06-02-2011, 3:35 PM
Here is the thing with carry handles.... if you order one from CMMG, the have ONE, Stag offers ONE, Spikes offers ONE, Sabre Defense offered ONE....... etc... I know Armalite for example offers regular AND NM variations...... but there is NOT one handle for M4's, and one for rifles..... they are the same handle.. an F marked FSB will use the same handle regardless of barrel length.

Hump0311
06-02-2011, 3:56 PM
I think I know why your off. Nothing wrong with the carry handle. When you zero it you need to put it on "Z".

You trying to get a BZO at 6/3 should be used for a M4 config.

This could be what's giving you the problems.

I in no way am trying to step on Diesel's toe's so hopefully will not get flamed for my 2 cents.

I know with optics the barrel length dictates the kind of optic used. In the Marines we have two different RCO's.

One for the M4's and one for A4's.

If you put the wrong optic on the wrong weapon you will be shooting off all day.

In that first picture you posted you can barely see the "Z". Try going a few clicks to that "Z" and see if this helps.

If you have already tried this step to no avail please disregard.

Pryde
06-02-2011, 5:00 PM
This happened to me, I thought it was the FSB too, I sent the barrel back to the manufacturer and they said it was fine, I was stumped. I took it to Randall to have him look at it and it turns out my index pin notch in the upper receiver was off by a little bit, he milled out the slot and shimmed it and everything is fine now. Apparently this is very common.

If its not the FSB check the index pin hole and you might find the culprit.

dieselpower
06-02-2011, 5:31 PM
I think I know why your off. Nothing wrong with the carry handle. When you zero it you need to put it on "Z".

You trying to get a BZO at 6/3 should be used for a M4 config.

This could be what's giving you the problems.

I in no way am trying to step on Diesel's toe's so hopefully will not get flamed for my 2 cents.

I know with optics the barrel length dictates the kind of optic used. In the Marines we have two different RCO's.

One for the M4's and one for A4's.

If you put the wrong optic on the wrong weapon you will be shooting off all day.

In that first picture you posted you can barely see the "Z". Try going a few clicks to that "Z" and see if this helps.

If you have already tried this step to no avail please disregard.

nothing wrong here. The z is used for zeroing, but thats not what his trouble was. he was dead on but needed windage to center. you can zero at any place on the dial by adjusting the FSP. the RIBZ and IBZ show how to adjust the manual stop of the drum giving you a lower setting than 6/3

missiontrails
06-02-2011, 6:42 PM
nothing wrong here. The z is used for zeroing, but thats not what his trouble was. he was dead on but needed windage to center. you can zero at any place on the dial by adjusting the FSP. the RIBZ and IBZ show how to adjust the manual stop of the drum giving you a lower setting than 6/3

I did use the Z.....at the 25m to establish 300m zero. You actually have to click back down to the 6/3 for the 300 zero. that's elevation... I can't wait to go to the outdoor 50...... That laser bore sight must be telling some truth......

NotEnoughGuns
06-02-2011, 7:55 PM
maybe theres a loose nut behind the stock. :p

vmwerks
06-02-2011, 11:58 PM
people have such thin dam skin... So when the guy told us we were wrong to have a 25m zero and we can not figure out why we were 6" off from a 100 yard target that is fine?

are you freaking kidding me??????????

don't expect me to NOT to slap you, when you slap me.

99.9% of the fights I get into on these forums is from jackwagons who don't think anything of slapping a guys post (or choices), but freak out when they get treated the same way.

Most of the old timers here are so used to treating people like shiat, that when I treat them like shiat they freak out.

In any event I wasn't telling him, I was telling ANYONE who is asuch a freaking idiot that they can not figure out why their shots are high to give up guns...it wasnt directed directly at the quoted person...but he did fire the first shot.

Actually no I am not kidding. Unless the other post has changed I am not sure how he "hit" you first. However this is not my issue, your post was full of good info but honestly after reading the first line I nearly skipped over it.

PyroFox79
06-03-2011, 12:42 AM
Hey at least your rifle can be zeroed. I've had rifles come back with brand new barrels that could not be zeroed. Its a real pain in the *** when you have to go back to the monkeys at the 3rd shop to get a new barrel.

dieselpower
06-03-2011, 8:47 AM
Actually no I am not kidding. Unless the other post has changed I am not sure how he "hit" you first. However this is not my issue, your post was full of good info but honestly after reading the first line I nearly skipped over it.

So you either
1) agree that a person who zeros at 25m is too stupid to hit a target at 100yards, and if they do hit it, they would not be smart enough to figure out why their POI is high

or

2) you are just skimming posts, not following the conversations and knit picking on me, because thats what people like to do.

I really bet its #1. Why?... Because you by now have read the post I quoted and still can't see something wrong with it.

analogy...
Don't use the 50 yard, IBZ or RIBZ zero. Use a 25m zero. Seriously -- otherwise you'll baffle yourself why you can't hit the gongs at 300yds -- because you're POA is 6" high!

If I were to post that dozens of guys would be screaming at me and calling me all sorts of names. I bet you would be agreeing with them. You see, people do not have issue with someone spreading FUD about another's views, but when a person turns the table on to them, they have an issue.

The statement I quoted is a slap in the face to shooters who understand a zero.... either way. It warranted a slap back.

A smart man once said, "...in order to get a persons attention you must apply a high level of stimulus...." Bruce Lee said, "They bruise your face, you break their skin, they break your skin, you break their bones, they break your bones, you end their life."

FreeFlyFreak
06-04-2011, 4:41 PM
Interesting read on the zeroing.

The best thing I read in that regard is here: http://ar15zeroing.com/

It details each of 3 methods and gives a summary of the pros an cons of each.

dieselpower
06-04-2011, 5:04 PM
Interesting read on the zeroing.

The best thing I read in that regard is here: http://ar15zeroing.com/

It details each of 3 methods and gives a summary of the pros an cons of each.

Thats the IBZ. They made another one called RIBZ http://www.ar15.com/forums/topic.html?b=3&f=18&t=328143 Revised Improved battle zero.

I see no pro and con of each, but thats ok. to each his own.

FreeFlyFreak
06-04-2011, 5:28 PM
Thats the IBZ. They made another one called RIBZ http://www.ar15.com/forums/topic.html?b=3&f=18&t=328143 Revised Improved battle zero.

I see no pro and con of each, but thats ok. to each his own.


At the end of the day it is all basically the same, the bullet flies the same...... just pick your zero distance(s):

You get a zero for 2 distances, everything outside if those you have to adjust for, up or down, either with point of aim or an adjustable rear sight.

With the RIBZ you will be zeroed for just one distance around 100yds (= most civilian rifle ranges I have been to) and adjust for any other distance (POI always lower than POA if not at zero distance, rather than sometimes higher sometimes lower.)

Its all really just personal preference it seems to me, the bullet flies the same, just choose your zero and know your aim point adjustments.

Oh by the way diesel......... I would like to see the figure 8 thing you were talking about earlier.

dieselpower
06-04-2011, 7:28 PM
keeping this chart in mind and understanding the red dot of an RDS appears larger when placed over a target a distance away from you,
http://i655.photobucket.com/albums/uu272/Wiringguy/Zerobulletpaths.jpg

the shooter can gage in their mind where their shots will strike. the benefit of a 25 meter zero is the impacts are above your aiming and the size of a 2 or 4 MOA dot equals the size of the error

this is a visual aid only. just something I wiped up as a talking point. the trajectory will vary depending on ammo, twist, wind, distance...blah blah blah

if the pic is too small try to copy it and save to your computer. blow it up to read it.

I'm not a good programer...LOL

http://i655.photobucket.com/albums/uu272/Wiringguy/25MzeroRDS.png

I have replaced it.

SixPointEight
06-04-2011, 7:49 PM
...jackwagons...

Lmfao. I freaking love that word.


OP, my CMMG needs the rear sight off-center to be zero'd, but it's not quite that bad. This isn't uncommon with CMMG uppers.

I do as Diesel said, and run the RIBZ on my carry handle upper.

25 Yards I'm at 6/3 +2 clicks(z marking)
50 I'm 6/3 -4
100 6/3 -6
200 6/3 -4

then from 300 out, I use the markings on the rear sight. Most the time I use the big aperture or the 50 yard zero. Sure I'm a couple inches high at 100, but I don't have to mess with crap to shoot.

SixPointEight
06-04-2011, 7:52 PM
keeping this chart in mind and understanding the red dot of an RDS appears larger when placed over a target a distance away from you,
http://i655.photobucket.com/albums/uu272/Wiringguy/Zerobulletpaths.jpg

the shooter can gage in their mind where their shots will strike. the benefit of a 25 meter zero is the impacts are above your aiming and the size of a 2 or 4 MOA dot equals the size of the error

this is a visual aid only. just something I wiped up as a talking point. the trajectory will vary depending on ammo, twist, wind, distance...blah blah blah

if the pic is too small try to copy it and save to your computer. blow it up to read it.

I'm not a good programer...LOL

http://i655.photobucket.com/albums/uu272/Wiringguy/trajectorydisplay2.jpg

Can we get a bigger picture of that lol

BIRDHUNTER757
06-04-2011, 8:03 PM
I no expert for sure. Go back to the second picture and take a good look at it. Is it just me or is the whole rear sight shifted to the right as well as twisted to the left? Sure looks like it to me. Has the sight ever been banged? Have you tried another detachable sight on the gun? If so, what were the results?

FreeFlyFreak
06-04-2011, 8:05 PM
http://i655.photobucket.com/albums/uu272/Wiringguy/Zerobulletpaths.jpg

That image shows why 25/300 is used as "battle sight zero"

Using that 25/300 zero, from 0-400yds you will be any where from 10" high to 5" low from POA...... not great for plinking cans on a 100 yd range but........

If you aim center mass at the "enemy" you are gonna hit a person........... somewhere on their torso from 0-400yds = "BATTLE SIGHT".

If you use the other zero's you will be closer to point of aim 0-200 yards (great for hitting cans on the 100yd range, or for closer range battle IBSZ) but after that it drops off sharply, and may miss the "enemy" altogether in battle at long range with a 30" drop at 400 yards, unless you compensate adequately.

At the end of the day, set your rifle up for your preference, know the way your rifle is set up and be able to compensate when needed, depending on the range.
That what I get from it all as a noob.

SixPointEight
06-04-2011, 8:06 PM
I no expert for sure. Go back to the second picture and take a good look at it. Is it just me or is the whole rear sight shifted to the right as well as twisted to the left? Sure looks like it to me. Has the sight ever been banged? Have you tried another detachable sight on the gun? If so, what were the results?

That was already talked about. There's a detent in the sight that tensions it that way. That's not the issue

kendog4570
06-04-2011, 8:57 PM
Regardless of which front sight/rear sight/handle/pin slot location you have, send it to me and I will set and fix your mechanical wind zero to within 1 to 1-1/2 moa of mechanical wind zero marks. $75 plus shipping back to you.
20 + years experience NRA Service and Match rifle building. FFL licensed and insured.
To the OP, whether you can see it or not, 95% of the time the FSB is out of plumb with the rear. The remainder percentage is usually a bad crown, upper receiver sight platform/center mis alignment or barrel mis-alignment.

dieselpower
06-04-2011, 9:36 PM
I split the drawing up. Once again this is just a talking point its not a bible or anything. It is the basics of how to use a 25m zero to hit targets out to 400 m without any hold over where you are hoping to hit a target you can barely see (4 football Fields away) with a 25m zero your POA=POI at 400 yards and its there you don't want to have to guess. Close up your POA=POI within your MOA of the optic and accuracy of your rifle.

http://i655.photobucket.com/albums/uu272/Wiringguy/50yardzerords.jpg
http://i655.photobucket.com/albums/uu272/Wiringguy/25MzeroRDS.png

SixPointEight
06-04-2011, 9:53 PM
Ahh okay.

I've always liked the 4 moa dot with a 50/200 zero. If you assume you're zero'd for the dead center of the dot, then with a 50/200 zero, you will hit in the dot (within 2moa of your aimpoint) out to almost 350 yards.

Though, your diagram makes sense too for a 25 yard zero, and would be good for a battle rifle. Fortunately, I only shoot paper and steel, so if my bullet's behind that dot I'm a happy camper

dieselpower
06-04-2011, 10:04 PM
^ The thing is, if a person knows their zero, then they know whats going on. This whole debate was caused because some guy said a person with a 25m zero was going to be baffled trying to shoot a target 100 yards away because there shots were 6" high. so they better just do a 50m IBZ or RIBZ, which is not correct. By that same logic the person would be baffled trying to hit a target 250 yards away when their shots were low.

with my old eyes I can't really see a target 400 yards away, let alone where my shots are hitting. Thats why i like the 25m zero. As long as I can make something out I am going to hit very close to it since thats the down cross zero trajectory.

to each his own :)