HHI 812: I tried those 300 grain bullets - my posts are in the 'Whitetail with a 45 ACP', er whatever. I didn't have much success with those heavy slugs and even wound up turning them around and shooting them 'butt-end' out becuase it made for such a neat profile. I relayed this to Northwest Custom Projectiles who went and did the same thing but with a bit more accuracy success than I enjoyed. They provided that in addition to the 300 gn bullet they also have a 260 gn slug in exactly the same profile as the 300 grainer and I am gonna try that one sometime this summer. If I get better accuracy from the 260 gn slug I will load them 'butt-end' out and see what sort of penetration I get.
Powder charges for the 300 grainer ran from 5.2 - 5.8 gns of Unique. If you load them soft nose out and use previously fired brass you may get pressure signs. If you load them 'butt-end' out you might be able to go up to 6 gns of Unique, or even better. Velocity might be the answer to stabilizing the 300 gn slug in the 45 auto. Mikey.