I have a reloading question!
I've acquired a 9mm AR-style carbine barrel, and I want to know if it's "safe" to load to normal AR-style pressures.
At this time my bolt is an industry standard blowback, non-locking bolt, and would be used the first few thousand rounds, presumably with factory range-grade ammo.
But let's say I manufacture a DI operated 9mm – custom drill a hole at about 2.5" out, and replace the hybrid bolt with a more conventional rotating lug design that will grab the 9mm rim.
According to Quickload, with the super-cheap 158 grain (yes, eek. But they were cheap) lead pills, I can concievably shove 5.7 grains of Accurate #5 underneath it, and for less than 50K of peak pressure, propel that bullet to almost 1350fps, north of 600 ft-lbs at the muzzle.
Or 5.2 grains, 1250fps/550 ft-lbs and call it a +p round. That doesn't sound so impressive, does it? I was getting better results pushing .357 SIG & 10mm to rifle-pressures, but since I don't have any components I was also using more reasonable assumptions.
Like: 140gr Hornady XTP, 8.7gr POWER PISTOL, 1790fps/990 ft-lbs out of a carbine. Or alternately, 8.2 grains, and within spec for 1470 out of a 6" long-slide. An extra 250 ft-lbs with two assumptions: AR style barrel extension, and an extra ten inches of barrel.
In case you only read half of that: tl;dr, I'm just playing with a spreadsheet, not actually assembling any of those loads I just quoted.
Yet.