Re: 22-250 rd ?
your going to be limmited to 55gr bullets or less. You may be able to squeek by with 60gr bullets, but that twist is really slow to hope for great results with anything greater than 55gr.
I had a SPS with 1/14 and it shot 55gr Nolser BT and Sierra Blitzkings like a house on fire. Great accuracy, but would not shoot 60gr bullets very well, 1+MOA @ 100 yards and 75gr Amaxas gouped around 9 inches at 100 yards rofl.
Expect about 3600+fps with the 55 gr, my load was around 3700fps with (dont quote me, reporting from memory, or lack there of) 38gr of H380 and 55gr BK, and could get around 3800-3950 with different powder combinations with the 50gr Blitzkings and 45gr Sierra and Hornaday bullets.
But for factory ammo, keep it under 55gr bullets for best results.