Happy with Converted M&P 357

[Tom Goodrick]

I just fired my converted M&P 357. I can fire it with very good accuracy (for me). I shot 20 rounds with my Ruger SR40C and then shot 30 rounds of 357 Sig using my old M&P 40 FS converted with a change to a new S&W 357 Sig barrel. I did much better with the 357 than with the Ruger on this particular day. (I used to shoot the 40 S&W M&P better than the Ruger.)

I appreciate the fact that S&W had the foresight to put the only caliber stamp on the barrel as viewed through the ejection port. My gun looks no different than a "factory-made" M&P 357. It will be permanent 357. I will not be switching back and forth between 40 and 357. I have another gun for .40 which I use for CC. The 357 will be used for home defense.

The recoil was no big deal. It seems rather impressive when combined with the loud and sharp report from the 357. The holes in the target are nice and round as though burned through. Holes for the 40 are a little raggedy.

I shot 125 gr Speer Lawman FMJ. I intend to shoot 125 gr JHP for defense - probably Speer Gold Dot.

 

[ppro]

I have the regular M&P 357 Sig and I also have a M&P 40 which I just put a sig 357 factory bbl. in.

Question: I noticed the color code (color on the factory recoil spring) is red on the M&P Sig, but it is yellow, on the 40 version. Do you or anyone know if the color difference signifies a different poundage weight ?

The Sig does have a bit more resistance to slide racking than the 40 with the Sig barrel installed.

Paul

 

[robrossk]

On the full size, I think the springs are the same part number. May want to check the S&W website.

 

[dswancutt]

My M&P357 has a blue spring. I bought a factory 40S&W barrel and it shots fine.

 

[mewisemajic]

The places where I've found factory parts all show the FS springs being the same regardless of caliber 9/40/357. One place stated the weight was 15#, the others said 16#. Wolff makes springs from 13# to 24# if you want to change the strength of yours to help tame the .357 Sig.

 

[Coastie762]

ppro, you noted the spring colors on your M&Ps. Are they full sized or compacts?

Both my full size 9 and 40 have the blue factory springs. My 9c has a yellow spring. I have a 40c inbound, now I'm curious to see what that has.

Does anyone know of a source for replacement springs/guide rods for the compacts? All I've seen are for the FS pistols.