What is your favorite AR-10 7.62 Load?

[Kurz]

I like to start conservatively as much as everyone else but in this case, the AR10 platform is not an M1A platform where you have to be conscience of bending the OP Rod. We have a straight shot all the way to the muzzle except for a tiny little hole to bleed off some of the plasma to run the BCG. Yes you should have an adjustable gas block so you can tune the rifle to the load. Yes, all of the powder should burn in the first half of the barrel so you aren't wasting powder but optimizing the velocity available before the gas port.

I give you Accurate AR COMP. Relatively cool burning but with a fairly fast burn rate. Berger 180 gr. Elite Hunter which is a dual use bullet since it will help you get to 1,000 yards on paper or steel yet you can hunt comfortably out to about 700 yards (1,000 ft lbs) depending on your velocity. Your 20" barrel, although decidedly short in my opinion, is perfect for using a suppressor for both target shooting as well as hunting. My load doesn't go subsonic until about 1,250 yards.

 

[Bill Norris]

I try to stay around the IMR-4064 range with my AR-10 .308. Seems to work well in my RRA A-4 20 " Heavy barrel. Have also loaded Win 748 and Varget with no complications.

 

[Bamban]

Bamban is telling the truth here. Those Berger 168 bullets fly very well. It’s not like a 168 Sierra SMK at all. It’s a long range bullet.

Michael, thank you.

A good friend (picked up by the Reserves after he won the P100 in 2016) shot the 168 Hybrids through his 20 inch, 4.5X scope at the NRA Nationals at Atterbury a couple of years ago. On the 1st 1000 yard match he posted 200-17X. The 168 Hybrids hung in there against some sleeker cartridges shot through some dedicated prone rifles, driven by some of the best LR shooters in the country.

 

[Michael C]

I built a M110 service rifle with 4.5x scope to play with. I am Palma shooter primarily, but still some shoot xtc. I was advised by an All Guard shooter on loads for 1000 yard service rifle, and the Berger 168 and 185 were both top picks. I was surprised how well it did at 1000 even before the obyermeyer chamber was throated. It’s just a rifle to goof around with but I like shooting it slung up at 1000. I live out west so getting to the nationals is difficult (had plans to go this year... oh well), but I would have to shoot a Palma rifle if I go. But I would love to shoot this there.

 

[kevinbritvec]

I've never heard of anyone bending an op rod on a M1-A. Reloading for semi-auto .308's is a balancing act. I use Lake City or IMI brass and reduced loads. The best data source available in a now out-of-print NRA publication, "Semi-Auto Rifles - Data & Comment". Former government ballistician Wm. C. Davis Jr. and Ed Harris fired over a thousand loads using Lake City brass, Sierra Match King bullets and Winchester primers through a pressure gun. All data was published with velocities (24" barrel) and chamber pressures using the C.U. P. method.

I have several Armalite AR-10's and I use Slash's heavy buffers.

Lake City Brass
Winchester standard large rifle primers
2.800" OAL
Shoulder bumped to SAAMI minimum - .001".
Sierra 168 grain Match Kings

40.0 grains of IMR-4895*
40.7 grains of IMR-4064*
43.0 grains of WW-748
40.5 grains of AA-2460
41.5 grains of VihtaVuori N150*

* You can increase these loads .5 grains if you want. start lower, work up.

I get 100% reliability and excellent accuracy. Varget, RE-15, Norma 203-B, VihtaVuori N140, IMR-8208, H4895 and IMR-3031 can all be used with good results. I disagree with the idea that semi-auto AR-10 rifles are capable of handling the same loads as bolt actions. It's not a safety issue as much as it is a function of reliability and parts longevity. Many starting loads published in manuals are actually maximum powder charges when using Lake City brass. A full 2.0 grain powder charge reduction from commercial cases is prudent.

 

[Bamban]

I built a M110 service rifle with 4.5x scope to play with. I am Palma shooter primarily, but still some shoot xtc. I was advised by an All Guard shooter on loads for 1000 yard service rifle, and the Berger 168 and 185 were both top picks. I was surprised how well it did at 1000 even before the obyermeyer chamber was throated. It’s just a rifle to goof around with but I like shooting it slung up at 1000. I live out west so getting to the nationals is difficult (had plans to go this year... oh well), but I would have to shoot a Palma rifle if I go. But I would love to shoot this there.

Michael,

Come down to TX in Oct and shoot in our LR Championship. If you take your M110, you will see a couple or so shooters fielding theirs as well. I am taking my hot rodded double lug M1A. I am shooting the 168 Hybrids.

https://bayourifles.us9.list-manage...5230f893ec09487377&id=6e51fa013c&e=b5dd1b3290

 

[243Mendoza]

Michael, thank you.

A good friend (picked up by the Reserves after he won the P100 in 2016) shot the 168 Hybrids through his 20 inch, 4.5X scope at the NRA Nationals at Atterbury a couple of years ago. On the 1st 1000 yard match he posted 200-17X. The 168 Hybrids hung in there against some sleeker cartridges shot through some dedicated prone rifles, driven by some of the best LR shooters in the country.

That is a record score for service rifle at 1000yd. It seems the NRA records are not up to date since it show the record for service competitor is 200-14x and that may be bolt rifle

 

[Bamban]

That is a record score for service rifle at 1000yd. It seems the NRA records are not up to date since it show the record for service competitor is 200-14x and that may be bolt rifle

My apology, my memory failed me. Your comment made me look up the score. He only shot 200-15X. Still pretty dang good for a 20 inch tube, and 4.5X scope.

 

[SPQR70AD]

I am surprised that no one mentions AA 2520 for any 308 bolt semi etc. it has the right burn rate for M1A and I have shot the smallest groups with that powder in a few M1A's and bolt guns. I have not tried the newer powders like AR comp but if you are having trouble finding the right powder try 2520

 

[Baer45]

I see that powder mentioned all the time elsewhere

 

[SPQR70AD]

I see that powder mentioned all the time elsewhere

yes it is never mentioned here. Every 308 I shot with that powder gave excellent results. I figured if someone was having trouble getting a load for a 308 give 2520 a try

 

[30378]

My Krieger bbl loves 45.5gr of Varget with 155 Berger VLDs at 2.795" OAL with Lapua brass and Fed 210m primers.

 

[Baer45]

I've never heard of anyone bending an op rod on a M1-A. Reloading for semi-auto .308's is a balancing act. I use Lake City or IMI brass and reduced loads. The best data source available in a now out-of-print NRA publication, "Semi-Auto Rifles - Data & Comment". Former government ballistician Wm. C. Davis Jr. and Ed Harris fired over a thousand loads using Lake City brass, Sierra Match King bullets and Winchester primers through a pressure gun. All data was published with velocities (24" barrel) and chamber pressures using the C.U. P. method.

I have several Armalite AR-10's and I use Slash's heavy buffers.

Lake City Brass
Winchester standard large rifle primers
2.800" OAL
Shoulder bumped to SAAMI minimum - .001".
Sierra 168 grain Match Kings

40.0 grains of IMR-4895*
40.7 grains of IMR-4064*
43.0 grains of WW-748
40.5 grains of AA-2460
41.5 grains of VihtaVuori N150*

* You can increase these loads .5 grains if you want. start lower, work up.

I get 100% reliability and excellent accuracy. Varget, RE-15, Norma 203-B, VihtaVuori N140, IMR-8208, H4895 and IMR-3031 can all be used with good results. I disagree with the idea that semi-auto AR-10 rifles are capable of handling the same loads as bolt actions. It's not a safety issue as much as it is a function of reliability and parts longevity. Many starting loads published in manuals are actually maximum powder charges when using Lake City brass. A full 2.0 grain powder charge reduction from commercial cases is prudent.

Do you use an adjustable gas block on your Ar-10s?

 

[mac86951]

I think M852 is about ideal for an AR. Maybe up the bullet to 175-178.

-Mac

 

[simplerider]

1000yd service rifle competition load for my AR10. 20in criterion 1/10 twist barrel with non adjustable gas block.

LC M118LR prepped and weight sorted brass (previously fired from my chamber)
CCI BR2 primer
39gr H4895
195gr Sierra TMK (.010 Jump)
avg vel: 2350

Also does very well with the M118LR loads but the 195s give me an edge at 1000yds.

 

[Baer45]

1000yd service rifle competition load for my AR10. 20in criterion 1/10 twist barrel with non adjustable gas block.

LC M118LR prepped and weight sorted brass (previously fired from my chamber)
CCI BR2 primer
39gr H4895
195gr Sierra TMK (.010 Jump)
avg vel: 2350

Also does very well with the M118LR loads but the 195s give me an edge at 1000yds.

Does that amount of jump fit your magazine or do you single feed them?

 

[simplerider]

single feed, not even close to fitting in the mag. The Sierra TMK is quite a long bullet.