Using 6946 magazine in 4053TSW

[jimdvan]

I took delivery of a 1999 4053TSW today. It came with the original box but no paperwork and only one blue follower magazine. Just to see what would happen, I tried one of my spare 6946 magazines in the gun and it fit. It also fed and locked open the slide after firing 5 rounds. Is there any reason not to continue to use the 9mm magazine?

 

[jimdvan]

I just took some measurements. The exterior dimensions of the two magazines are identical. The .40 feed lips measure. 357" wide and the 9mm measure. 332". That's only a dfference of .025".
The 9mm lips are only about .079" longer than the .40 and the 9mm follower is only .05" narrower. Not a lot of difference between the two.

 

[TTSH]

When I bought my pre-rail 4013TSW years ago, it came with one 4013TSW magazine... and one 6906 magazine. Fact!

That said, there are plenty of 4013TSW magazines out there and not crazy expensive.

++++++++++

EDIT (7/29/2019): Just to be clear, this was not some shop mistake. The previous owner of the gun had been using a 6906 magazine in his (now my) pre-rail Model 4013TSW before he traded it in. -ttsh

 

[JohnHL]

You're right, Jim!

I've noticed that also.

It seems the 40 mags have a sharper bend on the rear corners and also have that bump on the front to keep them from being inserted in the 9mm models.

Although I would be much more concerned about thoughtlessly inserting a loaded 9mm mag in one of my 40s and jacking a couple rounds of 9mm into that barrel before I got one to light.

While I know they fit and the lip dimensions are slightly different, I've never fired it that way.

I wouldn't trust it for self defense and there's always the danger of getting your loaded mags mixed up, but other than that, if it functions, I see no reason not to use it/them as range mags, until you get some more of the right ones.

BTW, the full size, 11 round 4006 style mags will work in your 4053.

John

 

[VASCAR2]

Mixing ammo can be a real concern. I was at a retiree shoot and the shooter next to me had a failure to extract on his Glock 23 40 caliber. He cleared the malfunction and finished the stage.

When we reviewed his target there appeared to be a key hole. On the next stage the shooter encountered another failure to extract. Upon inspection the round failed to extract from the chamber. The shooter had inadvertently loaded a few 9 MM cartridges in with his 40’s.

The pistol appeared fine but that explained the key holes in his target. Once all the ammunition were 40’s in the Glock 23 the shooter experienced no further malfunctions.

Inadvertently loading 40’s in a 9 MM pistol mag is another potential problem and a good reason to keep 9 mm and 40 ammunition in separate locations.

Even though a 9 MM mag might work I’d look for additional 40 caliber magazines.

 

[BLUEDOT37]

Not a lot of difference between the two.

I just found myself in the same position, only reversed, & found another difference you didn't encounter.

I just bought a 3556TSW (9mm) this weekend, in seemly unfired condition, & it included everything except a second magazine.

Not having any full-sized double stack 9mms in my collection to borrow a mag from, on a whim, I tried a mag from one of my full-sized double stack 40s in it.

Rounds feed & ejected fine (manually cycling) until the last round. It never feed because the slide would lock back with the last round still sitting on the follower.

The difference, & problem going from 9mm to .40 I found, is that while the relief notch on the left side of the follower, to push up on the slide stop lever, are of difference depths (the 40's notch is ~.004" deeper than the 9mm's), the last 9mm round is pushed up higher because the 40's magazine's lips are wider causing the follower to push up the slide stop lever just enough to lock back the slide back before the last round is picked up every time.

.

 

[jimdvan]

Even though the 9mm mag worked just fine I still like having the right tools for the job. When I found two, new 4053 mags for $30 each I bought them.

 

[VASCAR2]

Glad you were able to find a couple more mags.