LC brass year X vs. LC brass year X

[marchboom]

I have a bunch of Lake City brass (5,56) of different years. Is there a substantial difference between the different years (within 10 years) that would make a difference during load development? This will be used in an AR-15, not a precision rifle.

 

[jelenko]

I don't think so.

A key question is what accuracy are you needing?

Does the AR have a match grade barrel on it? [If not, you'll never notice the difference].

 

[marchboom]

Would like to get less than .750" group, 1/2 " if possible. Barrel is 18" Bear Creek Barrel (not a match barrel). Shooting 55 gr. VMAX bullets.

 

[Woollybugger]

Never looked at the date. I clean, trim and sort the brass by weight. Then they get annealed and sized to 20 Practical.

 

[jelenko]

Bear Creek Barrel

This could be an issue. Of the three Bear Creek barrels, 1 shot less than 1 MOA - the other two were 1 1/4 - 1 1/2 MOA.

 

[JB10]

For an AR i grab a handful of bulk brass and work up a load that is consistent. I do not try hard to get under 1 inch. I an not as comfortable behind an AR as i am a bolt rifle. If i remember the AR i have for predator hunting gets 3/4 to 1in groups. Its not a precision gun to me.

 

[Precisionhunter417]

Just year sort them and shoot untill the primer pockets wont hold or necks crack. Then start all over again. For a little extra consistancy i weigh them and toss the outliers high and low.

 

[moondog]

About 17 years ago, I bought a crapload of new LC 223 Brass for a bolt gun. It produced some very accurate ammo.
A buddy looked at the headstamp and said it was the "desirable" version. I had no clue there was a difference. Don't have that bolt gun anymore, but use it for match ammo in my AR. For Pdogs, I use mixed headstamp/manufacturer brass.

 

[hogpatrol]

LC or any brass can vary lot to lot in the same year of manufacture.

 

[mic2377]

I have not experienced any accuracy differences by headstamp that sorting by weight could not overcome.

The first step to AR accuracy is a good barrel. If after preliminary testing your BCA barrel doesn't shoot, get a different barrel and don't waste a ton of ammo on it.

 

[mgunderson]

How much effort is it to sort by year and shoot in batches? Experienced differences in LC LR 308 brass that I can't explain. Would be worth my time to sort by year.

 

[AckleymanII]

IN a custom 223 Match, bolt guns, Mixing years is suicide for accuracy, when looking for 3/8" groups and less.

Deburring the flash hole is another issue.

Checking for off-center flash holes is another issue; some years are just horrible.

 

[Mark M.]

Would like to get less than .750" group, 1/2 " if possible. Barrel is 18" Bear Creek Barrel (not a match barrel). Shooting 55 gr. VMAX bullets.

With an AR there's a number of things that come into play to achieve consistent accuracy. 1, match grade barrel, 2, would be your trigger. 3, your optics 4, consistency in your ammo, and 5, you're shooting ability.

 

[markm87]

Same as most... I only try to keep similar LC together so I know how tight the primer pockets will be. I don't want a random primer popping out into my fire control group and shutting the gun down.

 

[marchboom]

Using Rem brass I have shot a few .470" groups but mostly groups in the .520" - .600" range. So I'm satisfied with the barrel. In my collection of LC brass I have some 83, 84 and 85 years. Just wondering if I would get decent groups by combining those years.

 

[jelenko]

Using Rem brass I have shot a few .470" groups but mostly groups in the .520" - .600" range. So I'm satisfied with the barrel. In my collection of LC brass I have some 83, 84 and 85 years. Just wondering if I would get decent groups by combining those years.

The general advice would be to not mix them.
If you wanted/need to mix them, I would measure the case capacity of a few cases from each year first.

 

[Oso]

Just depends of what type of control /accuracy you are trying to achieve and also how much brass. If you have large pile of LC then sort by year. You may notice that in some of these years that the way that primer was staked/crimped is different. The old style was a continuous circular crimp around primer. Then some production lines switched to 4 distinct hash line around primer.

 

[JT27]

IN a custom 223 Match, bolt guns, Mixing years is suicide for accuracy, when looking for 3/8" groups and less.

Deburring the flash hole is another issue.

Checking for off-center flash holes is another issue; some years are just horrible.

I’m gonna have to respectfully disagree. At least in my case, that has not been my experience. Every single piece of 223 brass I put through my AR’s and my bolt gun has been once fired LC brass that I’ve picked up. One of my AR’s shoots 1/2 moa and the bolt is 1/4 moa, and better a lot of the time. I’m never sorted by weight or by year. 223 is such a fickle little cartridge I stopped trying to reduce my SD’s and ES’s. Never saw the point of sorting by year just because who knows when it was made in that year. One piece could be made in January and the next made in December. I don’t really know what that tells you. I think weight sorting would be more beneficial. Again, I don’t even do that. I did once by 100 pieces of Lapua to compare. The only difference I saw was that my wallet was $100 lighter. 223LC brass is really good brass. With the proper prep and annealing it lasts a long time too.

 

[marchboom]

I do a complete prep and anneal every time I load any cases. From JT27, "One piece could be made in January and the next made in December." Very good point and one that I have considered. Some LC head stamps look different even from the same year. So what am I supposed to think about that? Never weighed cases but I may try it just to see the difference. But I don't want to make this a normal part of my loading routine.

 

[jelenko]

I do a complete prep and anneal every time I load any cases. From JT27, "One piece could be made in January and the next made in December." Very good point and one that I have considered. Some LC head stamps look different even from the same year. So what am I supposed to think about that? Never weighed cases but I may try it just to see the difference. But I don't want to make this a normal part of my loading routine.

Absolutely. My understanding is there are many 'lots' of LC 223 brass in each year. So, on one hand, we're already using multiple lots when we sort by year.
On the other hand, by segregating by year attempts to reduce the risk there were significant enough changes year to year.

Broadly, if you're looking for 1/2 to 3/4 MOA accuracy, mixing is probably fine.
Again, if it were me and I wanted to combine years, I'd simply measure case capacity on a few cases first.