Now here's a stupid question. Can the thumb safety be added? Mine doesn't have one, but I see the insert that fills the slot where it would go.
Hey Gunny,
Nice pull, 40c's typically go for $399 with LE discount, so $325 is a great deal! I have the FS Pro Series in 40, with Apex FSS trigger/kit, and also have 9mm and 357Sig barrels, and can convert back and forth. I shoot a lot of 9mm when training/at range, and switch to .357Sig for defense/personal use. Oddly enough, I don't shoot the 40 that much, I just keep the barrel and some ammo on hand in reserve

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The 9mm barrel is easier to find, you can go with a S&W oem barrel, or a Storm Lake conversion barrel. Add a couple 9mm mags and you are good to go. For range use, you can even get away with using your existing 40/357Sig mags, you just won't be able to lock back on last round, and might have feed issue with the last round or two. I'd suggest going ahead and picking up a few 9mm mags along with the barrel if you want to shoot 9mm. You can find them at a bunch of places for $25 ea. Also, re the 9mm barrel, you can either try to find an oem S&W barrel, or get a Storm Lake conversion barrel. the S&W will be cheaper and it will work, but it will be *slightly* undersized in the lug area - this is S&W's attempt at preventing end users from doing exactly this change. There is a whole monster thread on 9mm barrel in 40 M&P Slide on the big AR forum I think, plenty of pics and measurements - worth a read if you are considering trying out 9mm in the 40. I started with the oem barrel (shown below), but wound up buying the SL conversion barrel for peace of mind. IIRC, the only other issue is the 40 breech is sized for the 40 while the 9mm is slightly less, so the general consensus is the 9mm conversion is best for range/training use only - not for carrying/SD use. Some will disagree there, though.
EDIT - the 40/9mm barrel thread I mention is linked here -
http://smith-wessonforum.com/smith-...ems-40-9mm-conversion-kits.html#post135820458
The S&W OEM 357Sig barrel is harder to find, but is a true drop in (S&W actually sold kits to LE with both barrels at one time), and no issues using for carry/SD. Also uses the 40 mags you already have, and is a blast to shoot, at least in a Full Size. Maybe not so much in a compact lol. Storm Lake also makes a 357Sig barrel for the compact, if you can't find an oem. 357Sig ammo is priciest of the three, and sometimes very hard to find, and is a bit finickier to reload due to the shoulder and case sizing, etc, but if you are experienced reloader it shouldn't be an issue.
As for adding the safety, used to you could not without a new sear block and some filing on the frame, but with the newer models that have the cutout, you can add a safety by exchanging a few parts - Get the parts from Speed Shooters Specialties (thumb lever and detent block with spring, part # 1960 & 2022 I believe, but call and double check). You don't need a new sear block either anymore.
Anyway, good luck with the 40c. I thinking about adding one as well, I've been carrying a buddies Glock 23 for a few days to try it out, but I still like the M&P's better. Actually heading to a gun show tomorrow, if I see a good deal I'l probably grab it, otherwise will just do an LE order for one...
Oh, and for ammo, I like HST... there are newer, fancier rounds, but imho HST just gets the job done. Horandy XTP Custom is also good, as are the ones you already listed.