If you want a 1911 in a high-power round I would go with the 10mm. It’s a round that was designed for auto-pistols. The .357 is rimmed for use in revolvers, which leads to feeding issues that are unnecessary.
If you want a .357 caliber I would go with either a .357 SIG or .38 Super, again both rounds are designed for auto-pistols. The .38 Super is a really fine round that dates back to the 1920s, and was designed to give more penetration than the .45 Auto.
All of the above have the advantage of not needing to do a lot of redesign of the basic 1911. The .38 Super is available from Colt, Springfield, and many other manufactures. The 10mm is still made by Colt and Dan Wesson, and probably some others.
+1 on the 10mm. If the op wants a 1911, more power than a .45 and if he wants my opinion. OTOH if he wants a .357 there sure are a lot of good revolvers out there, lever guns too.
Hey... One of each?
An interesting new round: 45 SMC. (Cut down 308 round, and a small magnum rifle primer!)
Double Tap has it in stock. It fits in a 45ACP pistol, but you have to use a heavy recoil spring.
185gn 1350 FPS
230gn at 1130FPS
Screaming fast round.
Sig is rolling a P220 in 10mm trim pretty soon. STI makes two flavors of 10mm now. The Perfect 10 and the Nitro 10.
The new Coonan’s feed rimmed cases just fine. There were mag issues with the older guns. This has been resolved.
“If you want a 1911 in a high-power round I would go with the 10mm. It’s a round that was designed for auto-pistols”
x2