So, I volunteered to help a friend's son diagnose accuracy issues with his new BAR MK3.

He'd originally tried numerous offerings of factory 150's (.270) and the thing was scattering the hell out of them - mostly all vertical stringing of 8-10".
The shots aren't walking up, it's complete randomness - one is 6" high, next 4" low, next 2" lower yet.

I assumed a scope and ring swap would cure it - and, after doing that (along with a good barrel scrub), I got the same sorts of no-rhyme-or-reason stringing with his various ammo offerings. He really wants to shoot factory stuff so I bought a box of 130 gr Winchester Deer Season and it pretty much repeated the same vertical nonsense as the 150's. I then assembled a smattering of mid-range reloads using the 130 BT, 130 Speer and 130 SST. Both the BT and Speer did a little better (4-5" - but same vertical randomness) and the SST actually produced a 2.5-ish" triangle that actually resembled a group (albeit rather large).

I know NOTHING about semi-auto rifles and have not been able to find much in the way of advisement concerning action screw(s) to help eliminate a potential issue there.

I'll likely work up some more loads with the SST but any help concerning tips/tricks for the rifle are appreciated.

Is 1 MOA too much to ask from the BAR? Is a return to the factory in order?

PS. I already beotched plenty about his semi-auto purchase so you can save the "tell him to buy a bolt action" comments. laugh

[Linked Image from i.imgur.com]

WWP53D