Badass.......yep, that was my Bowling Pin Load. I used a Keith-type 255 gr. bullet originally designed for the .45 (Long) Colt.
The RCBS mould # is 45-255-SWC-82050. It casts at .454 and should be sized to .451 or .452 (depending on what your gun likes) for a .45 ACP.
Here it is (at the bottom): http://www.rcbs.com/default.asp?menu...2=9&s3=83&pg=3
I started out at 6.0 gr. of Unique and worked up .1 gr. at a time 'till I got the hitting power and accuracy I wanted.
My old loading notebooks are buried out in the garage, but if I recall correctly, I finally settled on a load of about 6.5-6.7 gr. of Unique...but don't quote me on that. Start at 6.0 and work up .1 at time 'till you get a load your gun prefers.
Don't know what it chronographed at.....probably about 850 or so, but it really did a job on bowling pins thru my 1911 Pin Gun.
Note: this is a pretty square bullet, so if you want it to feed well in a 1911, you'll need a nicely polished feed ramp and a smooth transition into the chamber.