Quest for a Sub-MOA AR-10 in 308

[KurtM]

Almost forgot!!! One "trick" that might help close this gap is tuning your gas tube to gas key fit. This little trick can easily account for 1/2MOA, If it is dragging! Turn your upper upside down strip the bolt, you are working with just the carrier. Move the carrier back and forth by hand and see if you feel a drag when the gas tube enters the gas key. You can tweek the gas tube around with a screwdriver and get it so it just bearly has a light click as it goes in and the carrier seats. Drag on your tube translates directly to your barrel through the gas block, vertical and horizontal stringing can occured it you got lots of drag and it looks like you got a little stringing.

 

[conditionzero]

Almost forgot!!! One "trick" that might help close this gap is tuning your gas tube to gas key fit. This little trick can easily account for 1/2MOA, If it is dragging! Turn your upper upside down strip the bolt, you are working with just the carrier. Move the carrier back and forth by hand and see if you feel a drag when the gas tube enters the gas key. You can tweek the gas tube around with a screwdriver and get it so it just bearly has a light click as it goes in and the carrier seats. Drag on your tube translates directly to your barrel through the gas block, vertical and horizontal stringing can occured it you got lots of drag and it looks like you got a little stringing.

Nice trick / tip!!!

 

[KurtM]

It has to be upside down by the way, because the rounds in the magazine push UP on the carrier. If you do it right side up it can throw off the amount of drag felt.

 

[JEVapa]

Like what Kurt said, get some M118LR or Federal 308 GMM (same as AB39). If your rifle doesn’t shoot sub MOA with that ammo, do the tips/tricks and if it still doesn’t, sell it.

There is a subMOA 308 in the classifieds right now you can look at

 

[KurtM]

If you like the platform, don't sell it, get another barrel. Square the face of the upper, maybe thermo fit it, and try it again....

 

[ClintC]

Ok. went to the range today and took the 6 ARC. When I did the load development it was in the 50‘s. i had about 35 round to burn up. I know it was running MOA groups. it was 80 and did not produce the moa groups. Lever powder was used. I had 2 other loads I wanted to try before settling on powder charge. SD on original load date at 50 degrees was in the 7’s. Today at 80 degrees was 10’s. Tested another load that was a higher charge. SD was in the 4’s and back to moa even after dropping a shot. Thinks of changing powders. Just how temp sensitive is leverevolution

Added pictures

 

[rockchalk06]

What kind of speeds can you get out of H4350 or Varget?

 

[JEVapa]

I didn't see any loads for 6arc on Hodgdon's site. They had a bunch of different powders in their tables for various projos but not a lot that were all around powders for 6arc.

 

[ClintC]

What kind of speeds can you get out of H4350 or Varget?

Max charge for varget is 2450. I’m thinking accurate 2520 or CFE 223. Any thoughts

 

[rockchalk06]

I've never run any AA powder at all. Not sure the temp stability. CFE223 is a ball, so not sure how that's going to differ much for LR.

What's Hornady's factory stuff running?

 

[ClintC]

I've never run any AA powder at all. Not sure the temp stability. CFE223 is a ball, so not sure how that's going to differ much for LR.

What's Hornady's factory stuff running?

that I do not know. I know on one of there pod cast they talked about LR is the best powder for that round. But they are shooting Hornady bullets and I’m shooting Berger bullets.

 

[ClintC]

After looking over the burn rate chart and other forums. I’m thinks N540 or staball match. people are pitching a fit about LR being to temp sensitive.

 

[rockchalk06]

After looking over the burn rate chart and other forums. I’m thinks N540 or staball match. people are pitching a fit about LR being to temp sensitive.

I've got some Match I can send your way

 

[Ndenway]

Best my ar10 ever got for a 5 round group at 100 yards was just a hair over 1.5".

Winchester brass, wlr primer, minimum charge listed in hogdons load book Blc2 & speer 180gr hotcore.

All other bullets and loads done 1.75 to 2.5, my armalite likes low to medium charge weights, with the max charge with any bullet the rifle don't function well.