7.62X51 for AR-10 Match Round Recipes

[BigNate]

OK - I've done a bit of digging - and have come up with some related discussions - but I've not found a "share your recipe" type thread.   I'm going to start working on a load for match rounds for my AR-10(T).   I get that a big part of the process is figuring out what my gun likes - but I'd love to get any insights about reloading match rounds for the platform.   I'm sure that there are plenty of differences between these loads and some of the accepted .308 loads for bolt bench guns etc.   

• So - starting point load data? 
• Particulars around what to look for and avoid regarding how the loads interact with the gas systems on these guns? 
• Heavy 20" 1:10 twist barrel - conventional wisdom says that it is going to be happiest with 168 or 175 grain bullets - but as I dig and read I hear folks sharing anecdotal stories about going heavier and being happy with the results.  
• I'd like to assume that my 2.820" OAL for the M1A will be the same as my magazines appear to be a modification of the M1A mags - yes? 

I'm sure that I'll go through plenty of trial and error here - but appreciate any insights that you all care to share. 

Thanks!

 

[Sisco]

I will be following this thread with interest. Any posts by me on 308 loads in the reloading section archives have been used in my AR10T carbine, my AR10 rifle, or my Springfield Armory M1A. This is copied from a thread in reloading about 6 years ago.

 

•  
  •  

Posted March 28, 2015

Re15 works quite well with 168 gr and 175 grain. Pet load for accuracy and decent range for me is 42 gr RE15 with Winchester primers and 168 Sierra Match Kings. Winchester M80 brass. That load was given to me by a friend who is military retired Sniper. I messed with it up and down by .2 of a grain, but found 42 gr dead on was most accurate in my AR10 B 20 inch barrel.

100 yard group, and I am not that good of a shot. Old eyes and not enough range time.

•  

 

Edited July 26, 2021 by Sisco

[DNP]

So…you’re saying you got lucky?^^^…or that the load must be a good one in your rifle. That was some nice shootin for “not being very good”. 

[BigNate]

Thanks much Sisco... that's the sort of info I'm hoping to bundle!   Do I understand correctly that your AR10T is the Armalite original heavy barrel gun? 

Very nice group by the way... 🙂

[DustBuster]

Mineralman55 shared a spreadsheet in 2018, with various calibers and manufacture load data, don’t know if he put much custom experimenting into it.  Don’t know if it was for AR-10(Ts)

click on his name to look at his posts if you desire or actually search for Excell Reloading Database

Edited July 26, 2021 by DustBuster

[Sisco]

24 minutes ago, BigNate said:

Thanks much Sisco... that's the sort of info I'm hoping to bundle!   Do I understand correctly that your AR10T is the Armalite original heavy barrel gun? 

Very nice group by the way... 🙂

That was in my AR10 standard rifle. 1 in 11.25" twist. I can tell you results were very close to that with my AR10T carbine with the 16" heavy barrel'' and a 1 in 10" twist.  I would have to go back and find the pictures' I have had very similar results with 41.8 gr IMR 2895 as well as 42 gr Varget.

[Sisco]

36 minutes ago, DNP said:

So…you’re saying you got lucky?^^^…or that the load must be a good one in your rifle. That was some nice shootin for “not being very good”. 

A fair amount of luck, not much wind that day, and even a blind squirrel finds a nut every once in a while.

Edited July 26, 2021 by Sisco

[Sisco]

Here is a link to an applicable thread.

 

[Sisco]

Two other loads I have used.

Went out with two boxes of reloads. 168 gn  SMKs with 41.2 gr RL 15 and 168 gn VMAX with 42.5 grn RL15. 185 yards. Some flyers that were my fault (old eyes and coffee) but the loads.are good.Shooting my AR10 B model standard rifle off the.bipod.

Edited August 6, 2020 by Sisco

•  
• Quote
•  
• Edit

[Lonewolf McQuade]

Good shooting @Sisco!! I'd say those are good loads for you 👍

[BigNate]

3 hours ago, DustBuster said:

Mineralman55 shared a spreadsheet in 2018, with various calibers and manufacture load data, don’t know if he put much custom experimenting into it.  Don’t know if it was for AR-10(Ts)

click on his name to look at his posts if you desire or actually search for Excell Reloading Database

Thanks a ton!  Found it here:  

 

[BigNate]

Found this article referenced in a few places... So far I'm finding it pretty informative.   There are some 'obvious' things - but good new info as well. 

 

https://www.sierrabullets.com/reload-basics/reloading-for-semi-autos-and-service-rifles/

[98Z5V]

5 hours ago, BigNate said:

Found this article referenced in a few places... So far I'm finding it pretty informative.   There are some 'obvious' things - but good new info as well. 

 

https://www.sierrabullets.com/reload-basics/reloading-for-semi-autos-and-service-rifles/

^^^  That's a damn great explanation of it all, Nate.  There is nothing to pick apart in what they state.  Gas guns are just different.  I have some .308 Win bolt gun loads that I'd NEVER shoot through a gas gun.  One thing in there, auto-loaders, you ALWAYS need to crimp those rounds, and the Lee Factory Crimp Die is the best at this.  In order to get an effective, uniform crimp on every single one - they all need to be the same length, before you crimp.

Sierra is owned by CCI/Speer.  What impresses me most in that read, is that they're not hesitant to recommend parts or tools from other companies, that do a great job for auto-loader reloading.  That's class, right there. 

[98Z5V]

Here's my .308 Win load data (in this thread) that I talked to you about at the match.  Load data comes up on page 2.  It ROCKS.

 

"New" gun mandated re-looking my handload for it.  As I told you, the Hornady 178 HPBT is an excellent round.  The 178 ELD-M wasn't that much of an improvement.  When they dropped that 178 ELD-X, THOUGH!!!   Wow!  Big improvement in projectile technology. That was worth buying, and going through the "load development process" again, just to get a good load. Double-tap that pic to make it bigger, might need to triple it. 

 

Edited July 27, 2021 by 98Z5V