AR30 338 Lapua shoots very well I have only tried 250 Grn but the recoil is almost nothing, similar to my 308. Just the dam ammo is so expensive, I am currently considering re barreling to 338 RUM…..
Try HSM in Florence Mt for 338LM ammo at a more reasonable price. Do a search for "The Hunting Shack". They're load shot under 1/2 MOA in my TRG 42. They sell ammo world wide, to gov. and local agencies. I don't think you'll find quality match type ammo factory loaded in the 338UM. I lived on base for many years and set up my loader in the kitchen. Mike