Greetings, folks. Few tech questions

[Tigerclaw_x]

After having a HORRIBLE experience with Taurus 24/7 OSS 9mm (it shot everything just fine, but all over the place, since front of the slide was moving inside the frame by 1mm to either side), I pretty much gave up on polymer pistols and stuck to steel. (Cz75, Arcus 98DA, Tanfoglio Witness Match, ATI FS9,Taurus 92), however, after handling my friends Glock 17L and his S&W M&P pro, I decided to give plastic guns another try. I have few questions about M&P, which I hope you, gentlemen, can clarify to me. You obviously have expertise and knowledge. I seen the threads on this forum to similar subjects, but I just want to make sure that I understood everything right. English, as you can see is not my first language. Right now, I have a dillemma between Glock 35 and S&W pro. I like the angle on handle of Glock 35, however I like the trigger on S&W pro. So it is a toss up for now. So, few questions:
1. When going from 40 S&W to 9mm do I need to replace ONLY a barrel, recoil spring and magazines (obviously, mags need to be replaced as 9x19 and 40 S&W have different case dimensions and for reliable feeding mags need to match the ammo)? Do I need to replace bolt face? Do I need to replace extractor?
2. When going 40 S&W to 357 Sig, do I need to replace a recoil spring?
3. Is there a way to add an external safety to M&P? I am so used to having an external safety for my own piece of mind that I would really like to have one if possible.

Yes, I would like a modular gun (9mm, and 357 Sig).

Thank you for your reply.

With all respects

D

 

[RobzGuns]

Welcome to the Forum!
You only need to get aftermarket Barrels and mags. The recoil springs are the same.
Some simply buy factory 9mm barrels, as the 'fit difference' isn't that great, but personally, I'll spend a couple extra bucks and get a 9mm barrel that was made specifically to fit the .40 slide.

 

[Johnmuratore]

If the gun doesn't presently have a thumb safety, there needs to be notches in the polymer frame to accommodate it, but the safety itself can be easily installed by removing the sear housing block roll pin and the block itself and reinstalling with the safety.
The recoil spring assembly for the 40, 357 Sig, and 9mm are the same.
And +1 with Rob. Get the 40 to 9 conversion barrel. I did and it works perfectly.

 

[pfir]

I think that angle is important. I think that's why people love or hate Glock, the angle feels right to some and feels **** to me and others. Interesting that you love the M&P trigger. I do on some M&Ps but not on my new one (not yet broken in). Triggers can be adjusted or upgraded, the angle is the angle.

 

[pfir]

Oh, and you can order an M&P with a thumb safety. I did.