RBHarter
West Central AR
6.8 barrel and bolt from AR Precision . They do an 11° or 5/8-24 on a 5R barrel . 1-10 or 1-11 last time I looked at them . I have a 20" heavy rifle gas on one I shoot occasionally . 4198 for the 279-124 NOE to 2250 fps will give you somewhat over 1000#@100 , a jacketed bullet like the 120 SST should go 2450 on H335 if memory serves me and carry around 1400# .