I have a 14" twist 6mm barrel that I can't seem to sell. It is unchambered.
What round can I chamber this barrel for that will work good with 75gr and lighter bullets? I'll make it a PD gun good to 600 yds.
Depends on whether you want stupid / simple / easy or whether you want to be creative.
For simple, go with a SAAMI minimum -spec'ed .243.
Next options, 6mm BR (I never could get one to feed though) or 6x.250 (use .22-250, not .250 savage, brass).
My favorite is the 6x.284. I had a 700 short action with the chamber cut with a custom reamer spec'ed out for a 60 grain Sierra seated with the base flush with the bottom of the neck of a necked down Lapua 6.5x.284 case. A local guy bought the reamer then let the gunsmith chamber rifles for several of us with it. I tried the 55, 70, and 80 grain ballistic tips and 58, 65, and 75 grain VMAXes. The 80 didn't stabilize in my gun. The other bullets were ok but the 70 grain ballistic tip with RL 19 was the most accurate (57 or 58 grains, I forget which now). Not bug holes but good enough for ground squirrels to 400+ yards. Inside 150 yards it was hard to tell hits from misses because there wasn't even spray within a reasonable search distance. One time I thought I was missing. After the 7th or 8th shot I noticed a stringer of guts hanging from a branch about 30 feet up a tree.
I also had a 6mm Rem AI for a while. That one was a problem gun. It would only shoot accurately with Win 760 and I got some weird pressure problems. Load 50 rounds. Didn't matter how many I shot at the range, none to 40, no problems, but when I got up in the woods I'd get 3 shots normal, 4 sticky, 5th would blow the primer, and I'm not crazy enough to light off a 6th, I'd quit and go home to clean it. So .. not a real fan. Maybe a different gun would work better but I hate making the same mistake twice.
If I were doing it and the barrel is at least 26 inches it'd be a 6x.284. Redding dies, Lapua 6.5-.284 brass, RL 19 powder, 70 grain ballistic tips.
Tom
