Sorting projectiles by weight......

[Unretarded]

At what point is it just going down the rabbit hole sorting projectiles by weight ? 1 grain, .1 grain, 2 grains.

I would like to do this to build reasonably accurate ammo, but was wondering at what point most find it does not matter anymore or what is a acceptable weight difference.


This is 55 grain fmjbt ammo, but I will be doing many different calibers soon, so this info will apply to .270, .308 177 grain tmk`setc, match ammo, 77 grain 223 etc etc

I have time and I have a scale so this would be cheap to do , just looking to see what everyone considers reasonable.

My OCD ways tell me if it is measurable in grains I can sort it, but making tons of batches in .1 grain lots seems like overkill.


I would like to find a window that covered most of the lot and use the ones that fall above of below as plinking ammo.......just not sure where to set the window and how wide.

Thanks

[bigdawg86]

Wut? I have never heard of this, particularly for 55g FMJBT ammo. I know it is common practice to sort brass cases by weight if you are looking for precision stuff. I am loading for 6.5 Creedmoor (new build) and once I have fireformed enough of my converted cases (308 t0 6.5 creedmoor) I will sort by case (not bullet) weight.

I guess you can sort bullets but your ladder testing won't see any differences.

If you are loading for an AR just load 'em up and go. I have reloaded thousands of rounds for my AR and merely ladder test to ensure proper function and no overpressure. I have never even done the 100 yard test on my AR loads because let's face it, I have a red dot and iron's and am unlikely to notice a difference.

[LynnJr]

I would not waste your time of fmjbt bullets as they don't group well enough to be worth your time.
On the better bullets like the tipped MatchKings what you will notice is a couple bullets out of a 500 pack that don't fit at all.
And once you sort your bullets you shoot them in like groups so none are lost to the sorting process.
That said if your shooting 300 yards or less don't sort.
At the longer distances you will see the differences show up.
If you take two bullets made out of the same die they will have the same shape and form so the weight variation will effect the velocity and the BC of the bullets. You can plug the variations into a ballistic calculator and see if the vertical is acceptable to your form of shooting.

[jericho89]

As stated do not waste your time on 55 gr FMJ. The people who are trying to shoot one hole will weigh the their brass, projectiles, powder and primers and get them exactly equal. Even then it is not that they are more accurate than others, but they are more consistent and you can adjust your scope to the round.

[SWalt]

Only time I weight bullets is just to see how consistent a box of projectiles are. Just plain old curiosity.

[LynnJr]

If your weighing them you can also measure them by buying two comparator's that fit on your calipers. Measure everything into 0.001 groups and shoot them in like groups.
Bearing surface length ogive to boattail length bearing surface to heel length and once sorted you can then trim the meplats and re-point them with a tipping die before spinning them on a Juenke Machine. You can also slide them through bushings to check diameter.

[Unretarded]

Thanks everyone !

I scaled about 50 of the 55 gr fmjbt`s and they fall into 1 to 1.2 grain window........54.5 to 55.6.

With a lot of them being more within a .5 grain window. I will be doing load development with these to see what my gun likes, sub MOA is the goal, not the tightest group possible. I figure in theory that will give me a 1 inch to 6 inch group out to 600 yards, max intended use for the 55 gr fmjbt rounds.

I will also be loading some 75 gr hornady hp`s and some 77 gr tmk`s to try at the longer ranges 400 to 1000. To see what my rifle will do and to get a max effective distance on minute of steel......1 moa or under should give me in theory a 10 inch group at 1000 yards capable ammo, I know that is not the reality of it and groups will open up significantly at extended ranges due to shooter and enviromental conditions.


I hope this will give me a good base to start in on my larger caliber cartridges with somewhat of a understanding of the basics.


Once again this is within the scope of hitting medium to long range targets, steel or paper no matter the size.......18 inch paper or steel and considering anything on paper or steel as a hit........we will see where it goes from there.

First runs with factory ammo out to 400 were promising in the 5.56 16 inch barreled BCM......first groupings with the 6.8mm 22 inch barrel and factory ammo were sub moa at 100 ......hits were easy out to 600 on steel and were in a fairly good circle at 1000 yards........


My hope is with hand loads...better BC projectiles this will improve some.......

I still need to shoot and test the JP enterprises .308 with federal gmm 175 gr to get a baseline and load from there as that will be the primary focus rifle from 100 to 1000 yards, with more of a concern on group sizes and accuracy.

Starting with small caliber and cheap to get the ruff edges off the learning curve before sending expensive .308 projectiles and powder down range.

Thanks

[Witch Hunter]

If you are looking for accuracy, buy better bullets. FMJs are not known for their consistency or accuracy. It would be way easier to just buy some MKs or Vmax bullets. You might see way more gain.

[SWalt]

If your weighing them you can also measure them by buying two comparator's that fit on your calipers. Measure everything into 0.001 groups and shoot them in like groups.
Bearing surface length ogive to boattail length bearing surface to heel length and once sorted you can then trim the meplats and re-point them with a tipping die before spinning them on a Juenke Machine. You can also slide them through bushings to check diameter.

I was going to laugh.......

Then I saw your sig line......

Whole other science.....

[milotrain]

At what point is it just going down the rabbit hole sorting projectiles by weight ? 1 grain, .1 grain, 2 grains.

If I were to sort I'd sort to the .5 or .2gr.

I would like to do this to build reasonably accurate ammo, but was wondering at what point most find it does not matter anymore or what is a acceptable weight difference.


This is 55 grain fmjbt ammo...

Well you aren't going to see a difference with 55gr FMJBT, and you won't see a difference with sorted bullets (of high quality) in any autoloader out there. There are just too many weaker links above the weight of the bullet.

Do a test, go get a pile of bullets and make four batches of 20 rounds.
1. Sorted for .2gr spread
2. Sorted for the greatest spread found in the box. If it's 2gr then have equal divisions represented across the whole spread.
3. Second batch of greatest spread.
4. Unsorted

Now reload them with best practices in mind, and have a friend label each group as 1, 2, 3, 4 but not tell you which group is which. Shoot them all and compare the groups with the numbers after the fact.

Thanks everyone !

I scaled about 50 of the 55 gr fmjbt`s and they fall into 1 to 1.2 grain window........54.5 to 55.6.

With a lot of them being more within a .5 grain window. I will be doing load development with these to see what my gun likes, sub MOA is the goal, not the tightest group possible. I figure in theory that will give me a 1 inch to 6 inch group out to 600 yards, max intended use for the 55 gr fmjbt rounds.

You will never shoot a 6" group at 600 yards with 55gr FMJBT

I will also be loading some 75 gr hornady hp`s and some 77 gr tmk`s to try at the longer ranges 400 to 1000. To see what my rifle will do and to get a max effective distance on minute of steel......1 moa or under should give me in theory a 10 inch group at 1000 yards capable ammo, I know that is not the reality of it and groups will open up significantly at extended ranges due to shooter and enviromental conditions.

Don't bother with the TMKs, the 75 Hornady HPBT is better, it's a good bullet out to 600 yards but the Amax is better if you can load longer than mag length. Anything under 80gr bullets at 1k is a waste of time.

MOA is not linear, 1MOA at 100 yards is not the same as 1MOA at 1k (yes mathematically it is the same) but just because it groups at 100 doesn't mean it will group at 1000. .223s and .308s at 1000 are fickle mistresses, you want all the barrel you can find. In the .223 use an 82 Berger or a 90gr VLD but you need the twist rate to run it and the barrel to burn it. In the 308 use a Berger 155 VLD and run it to the bleeding edge of pressure signs. The new SMK palma bullet is ok, the Nosler, old SMK and other generic 155s won't be supersonic at 1k, especially with a short dumpy barrel.

[Whiterabbit]

Go get OnTarget and take the data yourself. It's actually amazing how much clarity that program can shine on what look like very similar groups.

Case in point, I was looking to track differences between using a chargemaster vs drop for a very specific application. Was it worth spending the time waiting for the measured charge?

On target results by group size were about the same. less than 15% difference in overall size. But OnTarget showed something like a 20% improvement in SD.

The ultimate conclusion? 15% group size decrease for this application could not justify the 20% improvement in SD and massive time-suck waiting for the CM to measure. Thus, I use the volumetric measure.

And I know this to be the case because I took the data and learned.

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Will sorting your projectiles by .1 grains help your groups? Probably improve SD. But I bet your overall group size stays the same. Meaning you won't out-shoot your ammo. Meaning it's a waste of time.

But let the data tell you that, not some internet guy. OnTarget plus a Chronograph will tell you ALOT.

[NorCalFocus]

Not to add to all the already negative pile we have here, but do you even have a gun capable of shooting the difference between .2 grains of bullets? Most factory rifles will not be able to do this. It really take a top quality barrel and gun smithing to really see the difference of bullet weights. Then like LynnJr said, inside of 300 yards it doesn't matter anyways.

There is other factors I'd look at controlling before worrying about bullet weight. Getting a scale that gets you the most consitaint charge, making sure your bullets are all seated the same and concentric, and that brass prep is top notch.

[Unretarded]

Thanks !

I will be putting this information to good use soon on some worthy projectiles and thru some good guns.

Just knocking the learning edge off on some cheap projectiles and thru some non picky rifles. All this info will pay off when I get to the good stuff !

Thanks again.

[Whiterabbit]

on target is pretty neat.



Numbers on the right are mine in Excel. =Stdev of the X and Y columns previous. On target gives me group size directly, in units of inches and MOA. That's another input.

If you looked at the targets, it's like any other calgunner in this forum posting a thread "help me interpret my target". They all basically kinda look the same. Based on the pic above, there's no room for interpretation of the pictures, no matter what they look like. The next step was clear. In order to shoot moly bullet, drop to 12 grains and keep testing.

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Even if you could look at the pictures and say "oh, 13 grains is the best moly", you couldn't tell me it's 45% better than the 15 grain target. But I know it.

[LynnJr]

How are you shooters using this system interpreting the data?