several questions about the .357 Sig:

[kcub]

1. What is the best .357 Sig Pistol?
2. What pistols in .40 or .357 work fine with OEM barrels of the other caliber? Of these, are 40 and 357 magazines interchangeable?
3. Is the .357 Sig going to be popular or wane? On the one hand HK is dropping it due to poor sales. On the other real world shootings are impressive and boosting its popularity among law enforcement rank and file. No department that uses it has dropped it.
4. Is there a point to having a .357 Sig or is a .40 with 135 grain ammo or 9mm +P+ with 115 or 124 grain ammo darn near the same and more available and cheaper? Is there testing to back this up one way or the other?

[dogtown tom]

kcub What is the best .357 Sig Pistol?

"Best" would be a matter of personal opinion. Sig, Glock, S&W all make pistols in that chambering.

What pistols in .40 or .357 work fine with OEM barrels of the other caliber? Of these, are 40 and 357 magazines interchangeable?

Glocks will and mags have slightly different followers but will interchange. Don't know about Sig or S&W.

Is the .357 Sig going to be popular or wane?

The number of Federal, state and local LE using the .357sig is miniscule compared to .40s&w. The commercial market sees .357sig less popular than 9mm/.40/.45/.380 This is due to the relatively high cost compared to other calibers.

On the one hand HK is dropping it due to poor sales. On the other real world shootings are impressive and boosting its popularity among law enforcement rank and file. No department that uses it has dropped it.

A better question might be is who had .40 and dropped it in favor of .357sig. Most of those agencies that changed to .357sig did so from 9mm I believe.

Is there a point to having a .357 Sig or is a .40 with 135 grain ammo or 9mm +P+ with 115 or 124 grain ammo darn near the same and more available and cheaper? Is there testing to back this up one way or the other?

I guarantee you there is comparison testing. Just Google it.

[Fixed Sight Training]

I like the 357 Sig but it is expensive and loud as hell. You can use the same mags for 40 S&W although it may need a different follower. Not sure about all manufacturers mags.

Most well made guns are about the same for reliability. Sig, Glock, HK, CZ, most 1911s, etc are all the same reliability wise and none stand out good or bad. They are all good, but all can malfunction.

Many guns available in 40 have a factory or aftermarket bbl in 357 sig. You have to decide what features you like and go from there.
Steel vs Poly,
Hammer vs Striker
Single action w/ a safety or a Double action first shot with a decocker or one in the middle like a glock or xd.

9mm, 40, 45, 357 mag or sig are all about the same stopping power wise with modern defense loads against people. Big dangerous animals are a different story. Where and how many times you hit are more important than what you hit them with so I would go with something you can find ammo for and afford to practice regularly.

I doubt the 357 sig will ever get to the popularity of 9mm, 40 or 45. It's one shot stopping power is marginally better, a small margin than 9mm but costs much more to shoot and harder to find ammo.

Also, that is a moot point because anything worth shooting once is worth shooting until it stops moving.

But it is loud, can have an impressive muzzle flash, can be switched over to a more common cartridge with a bbl change and is unusual enough to be cool.

[Dashunde]

You can run 357sig through Glock 35, 22, 23, and 27 using aftermarket barrels for sure.
No magazine, spring, or other changes are needed.

I dont *think* the OEM 357 barrel from a Glock 33 will work in the Glock 27, for example... but it might if the outside diameter is the same as the G27 barrel.

[DealHunter]

I know with 2x stack Sigs (226/9/4) all you need is a barrel (Sig even sells them) for .40 to swich (the mags even say .40/.357 on them).

Single stack pistols such as the P239 you need a barrel and new mags. Single stack .40 mags will "work" but I wouldn't trust them for CCW. .357s single stack mags you may have trouble even loading them (and with feeding) with .40 rounds due to an indentation in the mag designed for a bottleneck cartridge.

Of course, this is only with Sigs; M&Ps, HKs and Glocks may be different. I'd love to have a .357s 1911 (or a barrel for my .40 EMP) but I don't think they exist without custom work ($$$).

I quite like the cartridge (accurate, for me less felt recoil compared to .40) but I can find it at a reasonable price from specific local vendors. If I had to pay "full" price (even Walmart) not sure I'd still shoot it nearly as much. And yes, it is loud/has a large blast.

[noorked]

Both the HK USP compact 357sig & p2000 .357sig are changeable to .40 with only a barrel swap. Magazine follower is the same for the HK pistols in regards to .40 & 357sig

[Dan-O]

I dont *think* the OEM 357 barrel from a Glock 33 will work in the Glock 27, for example... but it might if the outside diameter is the same as the G27 barrel.

That is incorrect. You can just plop an OEM Glock 357sig barrel in it's .40 SW counterpart. The mag followers are different, but I have run .40 in a 357sig mag and vice versa with absolutely no issues. In fact, I prefer running 357sig in .40 mags as I can squeeze an extra round in the .40 mags due to the difference in the follower.

It relatively cheap to reload for. I can find once used 357sig brass for less than 9mm. 125 grain bullets are cheap.

Max Blue Dot loads at the range are head turners for sure