Changed barrel to .357 Sig, now is the weapon designed for both Cal's .40 & .357?
Will .357 round but any additional stress on frame and slide?
Read one article that stated, " .357 will shorten the life of the weapon".

I have a P229 DAK. The gun will shoot 4 different calibers. .40, .357sig, 9mm, and with changing slides .22lr. None of the calibers will put any extra stress on the frame.

quote:

Originally posted by schrack:
Read one article that stated, " .357 will shorten the life of the weapon".

One of those myths perpetrated by people who want to sound knowledgeable and wise without really understanding what they’re pontificating about.

Stress on the frame is a function of slide momentum: velocity and mass. The slide momentum is in turn a function of the momentum of the projectile and propellant: Newton’s third law about equal and opposite forces, and all that stuff that used to be taught in the seventh grade and later. The 357 SIG cartridge produces more muzzle blast than any of the other big four cartridges commonly used for self-defense in autoloading pistols and is therefore more intimidating to shoot for some people. The momentum of its projectiles, however, is no greater than common 40 S&W loads, and certainly no greater than common 45 ACP loads. SIG pistols chambered for those two cartridges, BTW, use the same recoil spring as 357 SIG pistols, and the slides and frames of 40 S&W guns are exactly the same as 357 guns.

In actual use by the Federal Air Marshals and (IIRC) the US Secret Service P229s chambered for 357 SIG reportedly held up very well. My first 357 P229 had nearly 8000 rounds through it with no problems before I sold it.

None of that means anyone should chose a pistol chambered for the cartridge, but we should base our decisions on fact, not rumor from an article or two.

I guess that one article was just B/S. sig would not sell something that would be unsafe. Thank You Sigfreund that clears that up.

Would you add any other parts, like heavier recoil spring?

I have never used anything other than the factory recoil springs in any of the guns I have that are chambered for 357 SIG. If I did, I’d feel it necessary to go with heavier springs in 45 ACP P220s and the pistols chambered for 40 S&W as well.

What I do with Classic line pistols is change the recoil springs every 2500 rounds. SIG factory recommendations have gone back and forth over the years. I have seen 5000, 3000, and 2500 rounds recommended, and I’ve settled on the most conservative recommendation.

If you are not familiar with this thread, I recommend checking it:

https://sigforum.com/eve/forums...0601935/m/6801056451

thank you for input.