AR15 bullets for reloading

[Pinecone]

http://optimalchargeweight.embarqspace.com/

0.1 grain increments are too small. You will shoot a LOT of rounds to find the proper node.
0.2 - 0.3 grain increments will work better.

Yes, mag length is the determining factor for many firearms.

 

[Melnic]

I'm going to work up some more loads.
On the issue of cases, If I weight my cases, and I"m concerned about accuracy, how much variation between case weight should I allow for?
I'm going to group like weights together in groups of 10.
Cleaned, Sized and trimmed cases are coming out about 92.2grn +/- 0.4grn

 

[Bolts Rock]

I'm going to work up some more loads.
On the issue of cases, If I weight my cases, and I"m concerned about accuracy, how much variation between case weight should I allow for?
I'm going to group like weights together in groups of 10.
Cleaned, Sized and trimmed cases are coming out about 92.2grn +/- 0.4grn

Sort by brand and if LC cases by year. Otherwise not worth worrying about unless you're shooting benchrest or 600 yards.

 

[Pinecone]

If you are that worried about case consistency, go buy some Lapua brass.

Or even Winchester or Remington. LC Match brass is good, but the standard LC is not that consistence.

 

[Melnic]

I have mostly PMC and LC, some FC and others that I can't recall.

I have sorted them but not sorted the LC by year just yet.

I only want to worry if I have to I guess that's the question.

I don't think I can shoot any smaller than 1MOA right now cause of the heavy trigger pull on it.

I got in some 53grn and 69grn sierra matchking today.

 

[dejacks]

I have generally found by selecting a powder that fills the case to a slightly compressed load for a given bullet helps velocity uniformity. Weight sorting the brass for the AR seems to help but only anecdotally. I like bullets in the green boxes and they seem to be consistent performers.

 

[Melnic]

I reloaded with a 69 and with a 53 matchking.
Not sure if my chrono was working right because it only showed about 2600fps at the max loads of the. 69. I used up to 24.2 of IMR4895 for 69grn and 25grn of IMR4895 for th 53grn. The 53 grn was at 2715fps.
At the lower load range on the 53, it was already 1MOA. The last load of 24.2 on the 69grn was compressed so I did not load any higher. The 53grn was not compressed. Never done a compressed load so I did not go further till I researched it.

Until I got to the last 5 of 69grn, the groups were 2MOA. At 24.2 it was just over 1MOA.
I'll work up more of the 53grn loads and maybe 5 of the 69grn just to see that I can duplicate my results from today.

 

[Pinecone]

What length barrel?

Hodgdon shows 53 gr MK with IMR 4895 starting load of 24.5 and max load of 26.4C (compressed). Velocity of 3012 and 3238, but likely with a 24" barrel. A 16" barrel could lose 200 - 400 fps.

69 gr Match King is 23.3 starting and 24.8C max. 2783 and 2953 for velocities.

Hodgdon reloading data online - http://data.hodgdon.com/main_menu.asp

 

[Melnic]

Bushmaster XM15-e2s HBAR, so 16" minus the muzzle brake
I used the Lee book and rouned up to an even value of grns then incremented .2grns at a time to give me some increments stopping about 2/3 the way for the first time out with these bullets and powder.

 

[Bolts Rock]

I have mostly PMC and LC, some FC and others that I can't recall.

I have sorted them but not sorted the LC by year just yet.

I only want to worry if I have to I guess that's the question.

I don't think I can shoot any smaller than 1MOA right now cause of the heavy trigger pull on it.

I got in some 53grn and 69grn sierra matchking today.

If the FC is large headstamp just pitch in the recycle bucket, it generally survives one reloading before the primer pocket gets too loose, not worth dicking with.

 

[Bolts Rock]

If you are that worried about case consistency, go buy some Lapua brass.

Or even Winchester or Remington. LC Match brass is good, but the standard LC is not that consistence.

I found my LC sorted by year to be very consistent, even once fired. The lot of 2000 LC 11 virgin I got from Natchez when it was on sale ran an ES of .4gr after match prepping (that's pretty damned good for 2000 cases).