Hi All,

Looking for advice- I did accuracy testing for the first time today on a new(ish) build & it's awful, 5-8" at 100 yards.

Background: This is an Armalite AR-10B pattern rifle, chambered in 45 Raptor (wildcat, just a 460 S & W magnum) with a barrel by Satern. I've got maybe 250 rounds through it, so far I 've been doing load development & only looking at velocity & pressure (measured by expansion of brass just in front of extractor groove). When I put the upper together, the barrel extension & upper had a snug fit so I didn't shim or anything. I did bed with blue Loctite.

There are no factory loads for this cartridge- handload only. I've tried two very different loads (bullet weight & charge) with the same results.

The rifle has a Leupold VX3 fixed power 6x in an Aero precision mount. I've remounted the scope several times to no change.

Early on, I had problems with the muzzle device not being threaded concentric & bullets actually hitting the last 'baffle'. I sent the muzzle device in & the same one came back bored out larger to avoid the problem. To rule this out as potentially affecting accuracy, I removed it & tested again with the same results.

I'm at a bit of a loss. Any ideas on potential causes?

I've heard that and improper gas tube fit/ alignment can be contacted by the BCG, which puts pressure on the barrel & can throw accuracy off. I don't know how to test for this- any advice on if this is worth checking, or how I could test for it?

Any advice appreciated.

Also- I'm posting this here because it seems like more of a general build problem. If this belongs in variants, just let me know.

Do you think the problem is the load you're making? Have you tried shooting a 'ladder test' to find an 'accuracy node'?

Reloading Ladder Test
Ladder Test Redux

Are you sure the crown on your barrel is good and the 'baffle strike' on the muzzle device wasn't caused by an improperly threaded barrel?

I'm not familiar with this cartridge so I'll ask the obvious. Is this a round that should be capable of 100yd MOA accuracy?  I know that your problem is a lot more than 2 MOA but their claims may be over exaggerated or only under specific conditions.

Their website says this:


Perhaps you should step your load way down and work up. This time watch for accuracy instead of velocity.

I would try a second scope.