9mm and .40 magazine compatibility

[fuzzymcnab]

I am looking at a shorty forty MKIII. It would be my first S&W in .40. Because of the lack of factory mags, and the fact that I have many factory 9mm mags, the questions is obvious. Will the 9mm mags work? I have had excellent result with Sigs and HKs taking both 9 and 40 mags but has anyone tried this with an S&W?
thanks,
fuzzy

 

[bigggbbruce]

If you can get 40 cal in a 9mm mag I'd like to see it.

 

[fuzzymcnab]

Hi Bruce,

The rounds fit the mag just fine, obviously a 10 round 9mm mag only takes 9 .40 rounds, but for range use that is just fine. Unfortunately, that's all I can check without the .40 gun and mag in question in front of me.
fuzzy

 

[Sevens]

My answer isn't very helpful but I can tell you that with fullsize 5906/4006 pistols, the magazines and the pistols are very specifically designed to NOT fit the other gun.

S&W uses bumps and ridges to ensure the wrong magazine isn't capable of being inserted.

 

[fuzzymcnab]

Sevens,

Thanks for the reply. Sorry to hear that, I was hoping my magazine problem was solved. Like I mentioned, I use my HK USP 40S&W mags in my P2000's and P2000SK in 9mm all the time. Of course, I would not bet my life on it, but I can run an entire IDPA match that way. Like many others, I have run 9mm in my .40 Glock mags in a Kriss Vector also.
fuzzy

 

[colt_saa]

It obviously comes with a 9 round magazine or two.

Just use the full size 4006 11 round magazines with or without the spacer kit for your extras

The magazines are for sale all over the place....GB.....eBay....etc

Here is an aftermarket manufacturer of the +2 spacer.

Precision Gun Specialties

I do not believe the factory parts are available any longer from S&W

 

[JohnHL]

I am looking at a shorty forty MKIII. It would be my first S&W in .40. Because of the lack of factory mags, and the fact that I have many factory 9mm mags, the questions is obvious. Will the 9mm mags work? I have had excellent result with Sigs and HKs taking both 9 and 40 mags but has anyone tried this with an S&W?
thanks,
fuzzy

Hi, fuzzy!

Your question got me wondering.
I've known for some time that the 9mm mags would insert and lock in a .40 (but not the reverse because of the bump on the front of the .40 mags) but I never tried to check if they would feed .40s until now.
I do not have a Shorty 40 but I do have access to a 4013TSW (the poor man's Shorty 40) and I tried a 5906 mag and a 6906 mag each loaded with a couple rounds of .40 ammo.
I did not attempt live fire but both mags hand cycled through the action just fine.

I hope you find this helpful.

John

 

[Alk8944]

fuzzymcnab,

As JohkHL stated the 9mm magazine will latch into the Shorty Forty just fine. I don't have a 9mm double-stack to check feeding, but my money is that it would work just fine as JohnHL stated his 4013TSW does. The best way to know is try it! As long as the .40 sits high enough in the magazine so the stripping rib on the slide will strip the rounds from the magazine there is no reason a 9mm magazine won't work. At worst it would be necessary to spread the magazine lips just a few thousandths!

The .40 magazines have a large bump about 1/2" above the base plate to prevent them from being inserted in 9mm guns, but there is nothing keeping it from working the other way. If all else simply use the 11 round 4006 magazines! They will hang out a bit and look odd, but there is no reason they shouldn't work just fine.

If the price is right for the Shorty Forty, and it has at least 2 factory magazines, I would go for it, they are really nice guns. I will say I like the look of the 1st & 2nd issue guns better that the Mk III, but there aren't that many around to be too picky if you want one!

Here is a link for a 9 round .40 magazine for the 4056TSW from Bud's Gun Shop. The disclaimer says it could be a stock photo that doesn't represent the actual item, but it sure looks like a Shorty Forty magazine to me except for no Performance Center logo on it!

 

[digiroc]

Shorty 40 magazines

It obviously comes with a 9 round magazine or two.

Just use the full size 4006 11 round magazines with or without the spacer kit for your extras

The magazines are for sale all over the place....GB.....eBay....etc

Here is an aftermarket manufacturer of the +2 spacer.

Precision Gun Specialties

I do not believe the factory parts are available any longer from S&W

I have the Shorty 40 and the 11 round magazines from my 411 and 4046 slot right in with no problems. If I'm in a carry situation where I need a mag change I'm not going to worry about the mag extending from the grip, and the extra rounds would be welcome.

Having said that, I like the look and functionality of the Precision Specialties mag extender. At first look I thought the Shorty had a bobbed lower and that would be a sweet mod.

I just received a 4040PD and the mag situation with that is not so easily solved. It came with a spare mag for a total of two but if I choose to carry it in my custom shoulder holster rig I'll want a third mag to have one in the gun and two in the attached mag carrier. Only problem is that the only 4040PD mags I can find are going for $150!

The 9mm mags for my 3913 & 3914 also slide in and latch up in my Shorty, but loading .40's in them causes them to jam up and fail to feed.

digiroc

 

[fuzzymcnab]

Thanks for all the great input guys. On the 11 round mag issue, not an option because I am in Kalifornia. I will of course buy 10 round 4003 mags if I find them in the future. I did decide to buy they gun, and it does come with 3 factory mags. It was no deal at $1400, but they come up so rarely in this state, and it is LNIB. Now, I will simply test with a variety of factory 9mm mags and report back.
fuzzy

 

[fuzzymcnab]

Alk,
thanks for the tip on the magazine, I ordered it.
fuzzy

 

[Alk8944]

Alk,
thanks for the tip on the magazine, I ordered it.
fuzzy

fuzzy,

Please send me a PM and let me know how it works, I might order 1 or 2. I only have 5 right now.

When I first got mine I was having feeding issues and called Cust Svc. They just sent me 2 or 3 no charge. This was about 15 years ago though, doubt they have any more. They were original P.C. magazines.

 

[ZoomieG]

Fuzzy,

I can chime in on this; I recently had the same thought. As I have acquired a few S&W 40s, and Mec-Gar makes readily available 5900 mags, would they be usable in the 40s?

Here's my experience with the following: 4006, 4003, 4013TSW(no-rail), 4013TSW, Shorty 40 MkII, and Shorty 40 MkIII.

As Sevens and JohnHL mentioned, the S&W 40 mags have a bump on the front about 1/3 of the way down the mag body. All the S&W 3rd Gen 40s have a corresponding channel cut in in the front of the magwell to allow these to slide home. Since the 9's don't have that channel, the bump will stop a 40 mag from being loaded in a 9. However, nothing prevents the 59/5900 mag from seating in a 40, with some exceptions. Aside from the color of the follower and the round count holes, the other differences that are easy to miss: the feed lips on the 40 mags are ~1mm wider, and the shape of the back corners of the mag body are different. The back corners of the 40 mags have a curve (both full size and shorty/TSW), but the 9mm mags have a sharper corner, to include 69/6900 short mags.

My 5900 9mm mags will fit in the full size and TSW guns. They will not fit in either of my shorty 40s. If you look in the magwell of the guns, the shorty 40s have rounds at all four corners. The full size 40s and later TSW guns have a sharp corner cut into both rear corners of the mag well flare; it actually looks just like the cuts in my 5900-series guns. My theory: the shorty 40s, being PC guns, had their mag wells cut to fit the new 40 mags, but the full size and TSW guns (production models) had the mag wells cut on the same machines as the production double stack 9s of the same frame size.

Just last weekend I took the 4003 to the range, and I actually loaded a Mec-Gar 5900 15 round mag with 11 rounds of 40 S&W. It loaded and fed just like one of the 40 mags, no problem.

So, to answer the question, a S&W 9mm mag will load and feed in a 40, as long as it has the same mag well cuts at the back corners as the 9s do. It seems that the shorty 40 series, at least, does not. I can't talk to any other PC 40s, but the shorties are a no go.

Regards,
ZoomieG

 

[TercGen]

Very interesting discussion, I've often wondered about this subject. The only observation I'll add is that my 5906TSW mag well is cut to accept .40 cal mags. I've had a cheapo LEO 4006 mag in my 5906TSW for dry-firing purposes for months now.

 

[digiroc]

I think there is a feeding issue with single stack 9mm magazines when trying to run 40's in them that is not present in the double stack 9mm magazines.

digiroc

 

[TercGen]

That's a bummer, I'd always thought to try and use a 3913 mag in my 4040 at the range sometime, just to see if it was a viable option. Maybe if enough folks back order them at Brownell's, S&W will make another batch for us (fingers crossed).

 

[fuzzymcnab]

Thanks again guys, this has been a really fun discussion. Zoomie, I really appreciate your in-depth info. You have nailed this issue completely. Of course that translates into the fact that the one .40 cal S&W I will soon possess is the THE gun that won't accept 9mm mags. Of course, I will try it nonetheless and report. Digirock, I agree that the single stack guns are a whole different issue. In my limited experience it is only the double stack mags that are sometimes trans-gender, oops, I mean trans-caliber friendly.
You guys are the best!
fuzzy

 

[ZoomieG]

Glad my info was helpful, Fuzzy.

As another data point, I had to go check more magwells after reading about TerGen's TSW; My 5943TSW and PC 9 Recon both have the magwell channel to accept 40 Mags. I had assumed the whole point of the bump/channel on 40s was to keep them from fitting in the 9mm variants, to prevent ammo/gun mismatch mishaps. Looking at photos online, it seems 9mm TSWs and PC shorty 9s (predecessor of my Recon) have the 40 channel.

There is probably a simple reason for the change: The TSW and PC shorty 9s are actually built on 40 frames. If you compare a 59X3 to a 59X3TSW, the frame of the TSW looks a lot more like a 40X3TSW. It is far beefier at the front rails, and has no frame "step" above the trigger. Likewise, the shorty 9 frames look exactly like shorty 40 frames, which have subtle differences from a stock 6906 frame.

This sort of change to a common frame for 9s & 40s is replicated in the M&P line, if I'm not mistaken.

As far as the single stacks (3913/4040), I don't have a 4040 or mags, but I can't load 40 in my 3913 mags. There is a seam on the left side of the mag where the sheet steel overlaps that is too narrow, preventing more than 1 round of 40 from being loaded. I would guess the 4040 mags and magwell are just slightly wider, much like the non-interchangeable 4506/1006 mags.

 

[fuzzymcnab]

This just goes to show that magazines are a whole story of their own. this became quite clear when I tried to put into service some old 659 mag bodies using 5906 orange followers. That was also a long series of posts but also very informative.
Blessings to you and yours
fuzzy

 

[GeoJelly]

If it wasn't for that cotton-picking bump on my 4013 mags I think they would work fine for range use my 6906. The feed lips are a little wide but none of the 9mm rounds popped out when I loaded them into the 4013 magazine. 6906 magazines have dried up completely - even 10-rounders - I guess they are made out of unobtainium ...