All metal .45's, and .40S&W vs .357sig

[Mello]

GoodKat
.40S&W vs .357sig

2: .40S&W vs .357sig, the rounds are basically interchangeable, so why should I go with one over the other and in what situations?

Double Tap loads:
.357 Sig
Bullet : 125gr. Speer Gold Dot JHP
Ballistics : 1450fps / 584 ft. lbs. 4"bb
Ballistics : 1525fps / 646 ft. lbs. 4.5"bb
125 x 1525 = 190,625 momentum
cross-sectional area = 0.0995 sq. in.

Caliber : .40 S&W
Bullet : Nolser JHP
Ballistics : 135gr. @ 1375fps / 567 ft/lbs- Glock 23 (4.0"bbl)
Ballistics : 135gr. @ 1420fps / 605 ft/lbs from a 4.5"bbl.
Ballistics : 200gr. @ 1100fps 538 ft/lbs from a 4.5"bbl.
125 x 1420 = 191,700 momentum
cross-sectional area = 0.1257 sq. in.

So, the kinetic energy is about the same so is the momentum.
The 40 has about 1/4 more cross-sectional area.
You have more bullet weight choices in the 40, from 135 up to 200. The heavier 40 cal bullets will have a higher ballistic coefficient and retain energy better. Considering most people don't shoot handgun beyond 25 yards that may not matter much.

Not a whole lot of difference, which is not surprising considering they both use the same case.

 

[Matrix187]

The .357 sig is hard to beat, especially for use by officers. The round feeds very reliably. It penetrates car doors/windshields extremely well while delivering a punch. But, taking the prices into account I would get a .40 for sure. You get high capacity with plenty of "punch", and near .357 sig performance overall. Both calibers do a great job..