It depends on your concept of "powerful"... The 45 is reknowned for its power, it shoots at a velocity of about 900 feet per second and packs a grain count (grains of gunpowder) from 165-230 depending on the type of bullet. The most powerful of which has 561 Joules of energy (414 lbf). However, the 40sw is, in fact, more "powerful". FBI's answer to gang activity in the 80s made Smith and Wesson develop this bullet that packs a smaller 'punch' because of it's lower grain count (135-180) but the larger full metal jacket has 606 Joules of energy (447 lbf). The 40s&w also travels at almost 1200 feet per second, almost 150% the speed of the 45. So, while the 45 may pack a bigger bang, the 40sw will deliver a more solid stopping force on its target.
Not worth the money it would take to do.
45 long colt is more powerful. It is usually used in revolvers and lever action rifles.
The stopping power of the .45ACP is legendary. While the short barrel costs some velocity is isn't enough to matter.
10-100 USD or so
Try e-gunparts.com, Brownell's, MidWay USA
Both can refer to 45ACP. 45 alone can also refer to 45 Colt
Follow the instructions provided by SIG
Out of the ones you've listed, .50 Action Express would be the most powerful, followed by the .45 ACP, followed by the 10mm, followed by the .40 Smith & Wesson.
No.
more powerful most powerful
75-375 USD
1977