N. Sniper, sorry to hear 'bout your bad luck with the Warbird, my brother and I bought ours at the same time (he had his bbl. braked by a gunsmith, I let mine alone) we have no problems with them so far, both rifles shoot 1/2 inch groups with identical loads (104.5 grns. RL 25, 180 Swift A-Frames, bullets coated with Tungsten Disulfide).
The only difference in our rifles is my brother gets 50 fps more, maybe the muzzle brake
helps out, I dunno...
My reason for Retumbo is to try to get the utmost in velocity (flatter trajectory, not bragging rights) without pressure increase using the 200 grn. Accubonds.