Weight sorting of bullets: acceptable range


PDA






capreppy
November 24, 2012, 12:31 AM
Weight sorting some Hornady .224 75gr HPBT Match bullets. What is acceptable tolerances? +/- 0.3gr? At what point will a person recognize a difference?

If you enjoyed reading about "Weight sorting of bullets: acceptable range" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
45lcshooter
November 24, 2012, 05:48 AM
For Match i would go 0-5 tenths of a grain. On pinking ammo and mist of my heavy ammo, its usually pretty good but i woulz say 1-2 grains off is good. Remember these are mass produced.

thump_rrr
November 24, 2012, 06:31 AM
It all depends on how far you go with the rest of the brass prep.

Are thr primer pockets uniformed and the flash holes deburred?
Is it all trimmed to the same length, chamfered, and deburred?
Was the brass weighed and checked with water for internal case volume?

FROGO207
November 24, 2012, 09:31 AM
+/-0.5 grain is what I use. I will only do that if the brass has been prepared the same and sorted by head stamp to a like tolerance weight wise. I do not bother to check water volume as my rifles are not that accurate anyway. As the above post indicates how far are you going with the brass prep? There are a lot of things that matter as much or more on accuracy than weighing your bullets IMHO. There are other sites on the net that deal specifically with precision shooting you may want to look into. Some check water volume, turn necks, use only the same brand/lot of brass, use Match primers, use swaged bullets and more. what is your level of want and at what point are the diminishing returns not worth bothering with. As in my case if your rifle is not capable of shooting so well is spending 4 hours loading 20 rounds worth the extra effort? YMMV

capreppy
November 24, 2012, 10:37 AM
For brass prep, I've done FL sizing to within +/- 0.002 (via headspace gauge) and trimming / chamfering / deburring via a Giraud Trimmer to within +/- 0.001 (OAL). I've deburred primer pockets, but have not uniformed them. I've not weight sorted the brass (yet), but they are all the same headstamped brass (Win). I do not currently neck turn.

More than anything it was an educational thing. Understood they are mass produced, but was curious about tolerances. I used +/- 0.3 as my tolerance for these Hornady Match Bullets and was pleasantly surprised to find 20 that were 0.4 or more lighter than 75gr and 40 that were 0.4 or more greater than 75gr. This was out of a box of 600. If I do +/- 0.5, I think there would be only be 5 or less that would have fallen out of spec.

helotaxi
November 24, 2012, 11:09 AM
Unless you're using a comparator and a dial indicator to measure bearing surface, ogive and boat tail for consistency getting too in the weeds with weight isn't going to net much in the way of tangible results.

JLDickmon
November 24, 2012, 11:36 AM
Unless you're using a comparator and a dial indicator to measure bearing surface, ogive and boat tail for consistency getting too in the weeds with weight isn't going to net much in the way of tangible results.
well put

SlamFire1
November 24, 2012, 11:44 AM
I have an article from Shooting Sports about the USMC Rifle Team and the loading habits with their 308 Match ammunition. They were using the M14 at the time.

They had a picture of a guy weight sorting 168 SMK's and putting them in boxes and the weight differences were tenth of a grain.

I don't think my powder scale is accurate to a tenth.

Used to be the old 174 FMJBT match varied by as much as 2 grains. They shot well out to 300 yards, but I would not shoot them beyond that unless they made me.

blarby
November 24, 2012, 05:01 PM
At what point will a person recognize a difference?

Depends on what your definition of "is" is.

For load development, I sort by .2gr variance in bullet weight, and .5gr variance in brass weight.

I find that the more refined your test data, the better off your results are gonna be.

Once I've got a load dialed in, I'll sort the components out I have that match that data and load them for "premium duty" reserve. The rest get loaded to that charge data, but using the remainder of the components for plinking use.

Unless you're using a comparator and a dial indicator to measure bearing surface, ogive and boat tail for consistency getting too in the weeds with weight isn't going to net much in the way of tangible results.

Well........ I agree that you can fine tune more using better tools- bullets that are 7-8grs apart can have significant impact point differences using the same charge.

While I agree that he's not likely to see that kinda swing on that bullet- this kind of variance (6-8grs) is common in bulk manufactured cast lead bullets. And boy oh boy, can you see it.


In rifle, at 100 yards, I start to see and "feel" I see differences in shots that are weight sorted to .2- against those that are .5grs or more in variance across the box.

If weight is all you are sorting for, I doubt you are going to see much variance in point of impact from 74.7 -75.3 grs.

If you are benchresting, you'll probably see point of impact difference between 74gr and 76 gr bullets...but thats only if your execution of shot to shot difference is flawless. Mine certainly isn't.

USSR
November 24, 2012, 05:54 PM
Used to be the old 174 FMJBT match varied by as much as 2 grains. They shot well out to 300 yards, but I would not shoot them beyond that unless they made me.

Yeah, I still got a bunch of those. I sort them by weight, but sorting commercial match grade bullets by weight is a waste of time. If you want to sort commercial match bullets, then sort them by ogive-to-base measurements.

Don

helotaxi
November 25, 2012, 09:50 AM
Well........ I agree that you can fine tune more using better tools- bullets that are 7-8grs apart can have significant impact point differences using the same charge.

While I agree that he's not likely to see that kinda swing on that bullet- this kind of variance (6-8grs) is common in bulk manufactured cast lead bullets. And boy oh boy, can you see it.


In rifle, at 100 yards, I start to see and "feel" I see differences in shots that are weight sorted to .2- against those that are .5grs or more in variance across the box.

If weight is all you are sorting for, I doubt you are going to see much variance in point of impact from 74.7 -75.3 grs.

If you are benchresting, you'll probably see point of impact difference between 74gr and 76 gr bullets...but thats only if your execution of shot to shot difference is flawless. Mine certainly isn't.Sorting gross weight differences is not getting down in the weeds. Sorting bullets to within .2gn is, assuming that is all you're doing for a sort.

If you enjoyed reading about "Weight sorting of bullets: acceptable range" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!