Oldbloke wrote:Well, you will be compressing a powder with an 1 oz load in front of it that isn't really intended to be compresses in that way. And shot guns operate at lower pressures. Say, 10,000psi compared to rifles 55,000psi
Huge difference in burn rate too.
No expert here, but I'd want to do a lot of home work before I considered what your suggesting.
I wouldn't be starting with one-ounce loads, and rifle powders do indeed like compression. Even Trailboss that ADI proclaims "should never be compressed" works just fine in 12ga., likewise they say to never reduce AR2206H (H4895) below 60% of "maximum charges", but I routinely run it at ridiculously low levels with zero issues
Yes, I know that guns are only rated to 12,000psi (half the pressure of .22LR), but I've shot a lot of reduced rifle loads that don't make that much pressure, sometimes the bullet barely drops out of the muzzle.
I did the experiments with rifle powder in 9mm because I couldn't find _any_ data online anywhere of anybody having tried it before, not even with exploding guns, which would surely get mentioned somewhere if it were an issue. Packing as much powder as it is possible to fit in the case, compressing it as much as humanly possible, and it still burns too slowly to make good velocity. It makes a usable cartridge certainly, but not a useful one. You need more barrel length to burn the powder.
In .410 I would expect similar due to the small bore diameter, but with better ability to create pressure due to the longer barrel. 12ga will be different as it will be very hard to get pressure to build fast enough in a rapidly expanding three-quarter-inch-diameter combustion chamber, you're almost burning the powder unconfined. It'd be like trying to generate power in an engine with a one-inch bore and a fifteen-inch stroke.
I do a lot of homework before messing about