Billy,
Although I cannot say for certain. MOST states do not allow 410 to be used for deer/big-game hunting. But MOST (That allow hi-powered ammo) will allow the 45Colt. Even loading the 410 as a single projectile firing 45 cal bullet...in the "eyes" of the law, its still a .410 and not legal.
MSP,
I would say with some restraint concerning yardages, you will be fine with the 45 colt loaded to moderate loadings. Some years back my little sister fancied deer hunting with the boys. i made up some light recoiling bullets for the Colt. I think I used about 20grs of IMR4227, but do not remember the exact load, so PLEASE CK FIRST. I did use the Speer "flying ashtray" 200gr bullet though. Its the one that's intended for the 45 Auto. I loaded it to about 1100FPS, IIRC. It was very accurate and performed well in my penetration experiments. Now this was 20 years back. Today there are many good bullets for the 45auto that you could press into service for your project. Just stick with the "OLD HEAVY" loads for the COLT model "P".
GOOD LUCK!!
CW