Exactly the same for me. 18” spr we call Larry. Everyone loves it but it only loves 55gr hornady sp. shoots them .5-.7 consistently with several powders and several different brand of brass…at 2800-3100fps.I've had a very similar experience with my 20 inch WOA varmint barrel. Loaded 69smk and 73eldM in Lapua brass, TAC and CCI#41 primers. Tried from min-max OCW tests 2 times. Would shoot about 1moa at best. Then loaded up 55gr Hornady SP with H335 in win brass with CCI#41 from 21.8-24.5gr and all were sub moa most .5 and under. Just bought a 24 inch WOA barrel, when it gets here I'm going to try the 69SMK again, and if it doesn't shoot I'll go try the lower grain bullets
Will shoot fusion 62s and 60vmax ok…like 1-1.5 min, 77/73s any combo is 1.5-2”
I’m looking to build a 16” gasser for 77s now because Larry is so picky. Considering proof steel, cle douglas but weight is a factor.