How picky are you?

[ra2bach]

How picky are you when sorting 5.56 cases by weight for accuracy?

I never used to sort by weight, and still don't for blasting ammo, but got a new batch of brass and started weighing cases. Most are LC 92 and they are falling in around 92G (which I think is cool, btw...) but there are some as low as 88G on up 95G. these are cleaned, deprimed, and crimp removed...

For loading accurate rounds how picky would you be regarding case weight - .1G?, .5G?, 1G?, 2G?, fugeddaboutit???

[eightmillimeter]

1) Figure out the average
2) Figure 1% of the average for really tight (2% for a little more leeway)

92 grains + or - 1% is

91.1 to 92.9 for the average group
89.2 to 91.0 for the lower group
93.0 to 94.8 for the heavier group

You do not need to sort by case weight if you are shooting at close distance (<400 yards) or shooting from a non-accurized rifle.

[ra2bach]

1) Figure out the average
2) Figure 1% of the average for really tight (2% for a little more leeway)

92 grains + or - 1% is

91.1 to 92.9 for the average group
89.2 to 91.0 for the lower group
93.0 to 94.8 for the heavier group

You do not need to sort by case weight if you are shooting at close distance (<400 yards) or shooting from a non-accurized rifle.

so 1% is good for an accurized rifle? that would be good because 87% of the cases I have fall in that group. actually all but a handful of cases fall within 2%. is that good enough for this rifle? I never sorted cases for an AR before, even my match service rifle...

my rifle is a 16" BCM Stainless Midlength barrel on a MUR receiver. very nice but I don't thank that's what you had in mind when you said "accurized", no???

I'm sorta chasing my tail on this because I'm not getting the results I think I should be. and to head off the obvious questions, I'm a good shooter using good ammo with 69gr SMKs. this load has always worked good in any rifle it was fired in.

oh and thanks for the reply...

[markm]

Not picky at all. In fact... every time we've really tried to shoot a great group and hand picked all the same headstamp, the group ends up being mediocre... like 3/4 to 1 MOA.

I do sort off some headstamps like PMP and Small font PMC (not the bronze brass) because those have dramatically lower case volumes.

We tried mixed brass vs. Lapua in .223 too... Lapua really didn't yield a significant improvement... In .308 yes... .223 nothing too exciting.

[ra2bach]

Not picky at all. In fact... every time we've really tried to shoot a great group and hand picked all the same headstamp, the group ends up being mediocre... like 3/4 to 1 MOA.

I do sort off some headstamps like PMP and Small font PMC (not the bronze brass) because those have dramatically lower case volumes.

We tried mixed brass vs. Lapua in .223 too... Lapua really didn't yield a significant improvement... In .308 yes... .223 nothing too exciting.

ok thanks. I shot CMP and never sorted cases but used mostly LC of the same year. then I shot some Benchrest and long range bolt gun and the attention paid to case prep was fanatical. it's no big because after weighing the whole lot only a handful of cases are more than 2gr apart.

I do have some of that PMC and it's pretty consistent too. my OCD won't let me mix it all together but maybe I'll use it for a different load or something.

thanks for the reply...

[markm]

Specifically that SMALL FONT PMC.... It's so thick at the web is sounds like steel cases when it rattles together or hits the ground.

[ra2bach]

Specifically that SMALL FONT PMC.... It's so thick at the web is sounds like steel cases when it rattles together or hits the ground.

hmmm, I'll have to check that. I have some with annealed necks with crimped and sealed primers, and some that weren't. all weighed out pretty close though...

[markm]

The brass is easy to spot. You can tell when you put a powder charge in it compared to all other kinds of brass... it fills the case up a lot more. The stuff I've found had no crimp.

[eperk]

Am I hearing this correctly? It's not necessary to sort by headstamp if shooting inside 400yds? .......... Dammit.

[mattiep321]

I did the same thing and sorted out the pmc bronze cases from my lc01 and lc02...In my case I loaded the PMC brass with Barnes tsx 70gr and 23.5gr of varget but it seems like I'm compressing the loads in these cases more than the lake city cases. I can only tell by where the press handle is in relation to when I start to hear crunching but the whole idea of compressing the load has me thinking I'm doing something wrong...
My point is that the volume difference seems significant...I started these loads at 21.0gr of varget and the PMC bronze cases still stood out as "compressing early"...but even the LC brass compressed the 21.0gr loads.
My accuracy with other 5.56 varget loads (haven't shot the 70gr Barnes tsx yet) came down more to primer pocket/flash hole uniformity as long as my cases were within 2% of each other: if I just removed crimp the groups suffered by as much as .8 moa...by uniformity the pocket and flash hole I was able to take my groups down to sub-moa.

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