.45lc shotshells

[Jack]

Yup, I agree with both of you that #12 is darn hard to come by. And buying a bag of it is serious overkill.
I make shot loads in 38, 44, and 45 ACP, and I use #9 that I scrounged off a skeet shooter. If you can scrounge a cupful of shot, you'll be making a buncha shot loads. Seems to me, at the range that handgun shot loads are effective, there's no need for big shot.
Adam, I believe CCI is now making 45 ACP shot loads using a shot capsule. I have not tried it, so I don't know if they will cycle the slide.
I make my own 45 ACP shot loads, with a rather complicated, cobbled up process I worked out. I end up with about 145 grains of shot, and good patterns. Cycling with an 18 pound spring is iffy... most of 'em do, but it's right on the ragged edge.