LC 7.62x51 brass variation by year

[z7]

i have a few hundred LC 11 pcs of brass, i have maybe 50 LC 07, and yesterday picked up 20 or so LC 64.

what sort of variation can be expected year to year with LC brass. for more serious "precision" work I will stick with one year and group them by weight, but how much does the LC plant vary year to year? it seems like it would be a real pain to sort by headstamp and by year, especially when i may only have a few LC 09 or something mixed in.

thanks

 

[243winxb]

real pain

I dont know? Maybe sort by year/scamp marks/weight to 3/10 gr after sizing, trimming, uniforming flash hole. (If 308 has scamp marks) FYI- Scamp marks-Some US GI cartridge cases are run on SCAMP (Small Caliber Ammunition Modernization Program) lines. This is HIGH speed cartridge case making equipment. Several lines of SCAMP machinery may be used to run cases througout the year, or on the same lot/year of ammo. Those dots identify which SCAMP line the case was made on. Any problem with an individual case could then be traced back to the acutal production equip used to make that run.

 

[ironworkerwill]

Now that you've wrote about scamps marks...what's the purpose? Sorry op, and for the ignorance.

 

[ArchAngelCD]

You are the one who has the brass you need info for. Why not just check the volume of each? We would be guessing unless we also had the same brass you actually have. Check the volume yourself!

 

[z7]

thanks for the replies, it will be interesting to look at the scamp marks on my LC 11 which i have quite a bit of

I had a small sample to test and here are my results.

LC 13 (only one) 182 grains
LC 11 (5 weighed) 180.4-182.1
LC 88 (5 weighed) 176.5-181
LC 64 (5 weighed) 179.4-182.3

It was a small sample size, perhaps some variation by year, but no correlation, the older ones were not lighter/heavier.

i also weighed some R P brass at 166-167 grains. surprising how light it is

 

[USSR]

...for more serious "precision" work I will stick with one year and group them by weight...

For "more serious precision work" you will not use Lake City brass, irregardless if you sort it or sprinkle fairy dust on it.

Don

 

[z7]

For "more serious precision work" you will not use Lake City brass, irregardless if you sort it or sprinkle fairy dust on it.

Don

I don't do the serious precision work that many do. I have a good rifle, but not a $3k+ rifle with $2k in optics, so if I can stay under an inch at 100yds I consider that serious precision work and am very happy for it.

In the event I want something more, I will invest a few months pay and get some lapua brass (and a gun that doesn't eat it like my AR does)[emoji6]

 

[ArchAngelCD]

z7, I wasn't talking about weighing the cases, I was talking about checking volume. That is usually done with water but you can also use a fine ball powder. Case weight can change without changing the case capacity.

 

[z7]

To measure volume they would need to be resized and or fired in the same chamber correct? Some were fired in a 240 so they have ballooned, the lc 64, 13 and a few 11 were shot in an ar10 while the 88 was a lmg
I will run them through a small base die, load and shoot them a measure after

 

[243winxb]

Sort by weight after fl sizing, trim, uniform flash hole.

 

[Sunray]

"...can stay under an inch at 100yds..." A lot will depend on your rifle, but meticulous loading techniques will help. Everything exactly the same and the powder charge weighed vs thrown makes some difference.
Depending on the year, LC 7.62 NATO brass is made for MG's mostly. Isn't exactly precision shooting brass. Personally, I'd just load it and forget the bench rest techniques of weighing and checking volume with milsurp brass.

 

[Maj Dad]

Surplus/fired GI brass is for banging away at non-armed opponents like paper targets, rocks, steel plates, and for informal matches. If you are serious about accuracy, start with new brass of your own choice (won't go there!) and work up loads the old-fashioned way. You can intellectualize until you're blue in the face on differential brass, but if you want accuracy and repeatability, start with new brass. I shoot the dickens out of 1x fired GI brass in my M1s and M14/M1As, but only for "plinking."

irregardless

AUGGGHHHH!!!!