Abit of thread revival here, have you shot the 55sbk as well as the 53vmax?For mid weight 22 cal bullets it's hard to beat the 53gr Vmax, you can shoot it faster as well as it has a higher BC than nearly all 22 cal bullets up to 60 grains. I shoot these in my 223AI and 22-250, they shoot extremely well in both.
How many rounds down the pipe? Have you tried the 75 eld or 77tmk in this barrel?I shoot a fast twist 22 creedmoor..( 1and 7) i shoot 90 gr. Berger vlds out of it around 3300 fps.. its a savage model 10 varmint target action with a heavy varmint contour 26 inch criterion pipe. It shoots 1/4 moa pretty easy and better than that on a good day.. heres a 5 shot group at a 100. And 4 in a bottle cap at 250.. i think its accurate.. does great on out there as well..