40 cal to 9mm conversion

[Jaxb_65]

Ok guys and gals , im going to do the 40 to 9 barrel swap im sure this has been asked and ive seen a few answers , but will the 40 cal mags work or will I have to get new mags . Thanks in advance and Happy Shooting

[scattershot]

They'll work occasionally, but not dependably enough to fool with. The conversion barrel works nicely, though, with the proper mags.

[Jaxb_65]

I was told I can pinch the top of the mag just a little bit, I ordered the barrel today, guess I'll start pricing some mag. Thanks so much for answering.

[CGhelofxr]

No, the .40 magazines will not work, you will need 9mm magazines

[Jaxb_65]

Thanks , im still looking for a deal on mags . Are mec gar or pro mags any good

[OKFC05]

Originally Posted by Jaxb_65

Thanks , im still looking for a deal on mags . Are mec gar or pro mags any good

MecGar is the OEM contract manufacturer of S&W M&P magazines. They do not sell them under the MecGar brand at retail. Just get the S&W OEM magazines at the best deal you can find. Brownells sent me an ad they had them on sale.


IMHO, ProMags have serious QC problems.
Promag, any good?

[CGhelofxr]

Originally Posted by Jaxb_65

Thanks , im still looking for a deal on mags . Are mec gar or pro mags any good

Greg Cote LLC

[scattershot]

Second Greg Cote, and Mec-Gar mags are excellent.

[retired2006]

I have used these, they are very good, actually like them BETTER than factory. Available from Brownells, which also has the S&W factory mags on sale for 22.00 !

S&W M&P 9MM 17-ROUND MAGAZINE | Brownells

[Slingn]

Ive tied two different swaps in mine. The 357 sig worked fine in the 40 mags. The 9's didn't work in mine.

[Saudade]

OK, here we go!!!

Bear in mind I live in CA where we are restricted to 10 rounds.

I bought some Promags for my FS. Frankly, they are ****! If you spend a few minutes on your favorite search engine, you'll find tons of complaints.

The spacing on the feed lips of the mags on a .40 are a bit wider than on a 9. This can cause feeding problems. For range use only, you *may* be OK. I would not squeeze the lips closer (OK, that sounds improper) since you may use them for .40 and possibly cause problems there.

Greg Cote is an outstanding vendor.

If you proceed with a barrel swap, please be careful to keep .40 with .40 and 9 with 9. Again, you can search to see the results of shooting a 9mm out of a .40 barrel.

[Raisin]

Try these guys for new magazines. Good prices on S&W magazines.

Smith & Wesson S&W M&P Shield 9mm Luger 8-Round Stainless Steel Factory Magazine

[Jaxb_65]

Thanks for all the answers and advice , this is an excellent site . I wish I would've ordered mags when I ordered the barrel and saved on shipping. Ill check these leads and get back when I do the swap . Barrel should be in the 20th.

[LD-Ordie]

I bought my barrel and a factory mag on eBay for less than I could find from the big distributers, free shipping too. A great conversion to do, also did it on my G27