45acp and trailboss
 

Rocky, could trailboss be used in a 1911 pistol chambered for the .45acp?

I rather doubt it. There just isn't enough case volume with the bullet seated.

Trailboss is an extremely "fluffy" powder - it was developed to take up most of the otherwise empty volume in big cases, yet give light loads for Cowboy Action shooting. It takes a case-full in a 45 Colt to generate 800 fps or so with 200 gr bullets. So there certainly wouldn't be enough room for it in a .45 ACP with the same bullet.

Thanks Rocky, i load the 45 colt and there is plenty of room, even with max load, if i use a 225 gr. lead bullet (so i can get it out if it does`nt exit the barrel) it would be okay to try then? Using minimum loads with a progressive press theres a chance to double charge a round, with trail boss that would be impossible then right?

Yup. Oh, sure, go ahead and try it. The worst thing would be a stuck bullet, as you say.

I'd predict very low velocity, probably will not function the slide. But if it does work, you've discovered something! Load ONE and see what happens.

Hodgdon lists loads for the ACP with Trail Boss on their web site. They show 750-850 fps depending on bullet. I don`t know how well your gun will track Hodgdons data but it is worth a try IMO.
One has to remember the smaller the case volume the higher pressures will be with same wgt loads and bullets. The huge 45 LC may need a full case of powder to reach 800 fps but the smaller ACP case may only need 1/2 that amount with the same wgt bullet.

http://data.hodgdon.com/cartridge_load.asp

Rocky, level full held 8.2 grains. So i loaded up a round, 4.5 grains went easily into the case, a bit late to fire up the chrony, but it had decent recoil, ejected the empty, locked back the slide. So i will say that might be about right.

I'll be dingled. Well, always happy to learn something - even when I'm wrong!