For those of you that do not visit the lower 48 forums.
Many of us have been talking about this cat for years. I decided to go ahead with it since many like the 30 cal bullets. This cat will be very close to Marty Terweem's 30HRT. Both use available 30 Herrett dies and 6.8 brass. The only difference is in the freebore length and the trim to length of the case. 1.580 is the length to the wall, 1.570 is trim to length. The shoulder is 30 degrees. The shorter case length I use allows all of the 125 and 130gr bullets and some 150gr bullets to be used correctly positioned in the freebore of the chamber. The 155 Amax should shoot well. The barrels have the same 1 in 11.25 twist 5R rifling that the 308 barrels have. For plinking the 147gr FMJs will be cheap. The 30HRT and 30 Herrett AR will push bullets apx 200 fps faster than the 300 BLK for those intending to hunt deer and hogs.
1680 is the #1 powder from all of the testing I have done. 4198 and Re7 work but the ball powder allows heavier charges.
28.5gr 1680 behind a 125 TNT hit 2500fps out of a 16" barrel.
30gr 1680=2594fps
30.5gr 1680 =2655 and I think there is a little more room to go up.
27.5gr 1680-150 Nosler=2360fps--close to max but I shot 28 with no problems.
Many of us have been talking about this cat for years. I decided to go ahead with it since many like the 30 cal bullets. This cat will be very close to Marty Terweem's 30HRT. Both use available 30 Herrett dies and 6.8 brass. The only difference is in the freebore length and the trim to length of the case. 1.580 is the length to the wall, 1.570 is trim to length. The shoulder is 30 degrees. The shorter case length I use allows all of the 125 and 130gr bullets and some 150gr bullets to be used correctly positioned in the freebore of the chamber. The 155 Amax should shoot well. The barrels have the same 1 in 11.25 twist 5R rifling that the 308 barrels have. For plinking the 147gr FMJs will be cheap. The 30HRT and 30 Herrett AR will push bullets apx 200 fps faster than the 300 BLK for those intending to hunt deer and hogs.
1680 is the #1 powder from all of the testing I have done. 4198 and Re7 work but the ball powder allows heavier charges.
28.5gr 1680 behind a 125 TNT hit 2500fps out of a 16" barrel.
30gr 1680=2594fps
30.5gr 1680 =2655 and I think there is a little more room to go up.
27.5gr 1680-150 Nosler=2360fps--close to max but I shot 28 with no problems.