SHIELD 9MM & 40 S&W MAGAZINES

[robkarrob]

This question could be easily answered by someone that has access to both the 9mm and 40 Shield magazines. I am trying to figure out the reason for the 40 mag drop problem. I did have the problem and it is now fixed with the "bump" added to the magazines. My question is: are the magazines the same?

I would think they are different since the 9mm didn't have the drop issue. I am sure the frames are the same. So the magazine well width should be the same. Are the magazines different in width to adjust for the .040 inch diameter difference between the two different cartridges? Logic would be the 40 mags should be a little wider, but the problem with the drops is the 40 magazines are too narrow. There is too much side to side play in the mags and the catch has a very small hold on the mags. When firing, the recoil is enough to cause the mag to move sideways enough to clear the catch and cause the drop. S&W added the bumps to make the mags wider, at the catch area, to hold them in place.

I can easily load 7 rounds of 9mm into my short 6 round Shield 40 mags. This is the same amount the 9mm Shield short mags hold. I can easily load 40 S&W rounds into some of my non S&W 9mm magazines. Maybe the magazines are the same?

Can someone that has access to both mags compare the width just below the mag catch slot. Because the magazines are tapered in that area, the easiest way to measure them would be to outline the mag on a piece of paper using a fine point pen or pencil. Then align the other magazine over those lines and compare the width. A caliper or micrometer could be used to get the actual width between the two lines. I have attached two photos that show that on my 40 mag. The width between the lines is .495 inch. Thanks for any and all help.

Bob

 

[Smitty357]

I thinks the theory behind this relies on a lot of different factors. One factor that I have discovered is the way the shooter holds the gun. For instance I have a buddy who has the mag drop problem. However, I have shot just over 300rds through it for him and I cant get the mag to drop. He shoots it and puts not even 50rds through it and it'll drop.

I'd be willing to bet that most of these are caused by user error. Do i think there is a problem with the gun (yes). But it's 10x's worse when u add user error into the factor.

Now on the other hand, I also have the Shield .40 and ive never had a mag drop issue. And believe it or not when my buddy shoots it, it doesnt drop mags either. He cant get over the fact that his drops mags but mine doesnt drop mags. But at the same time he hates it because his doesnt drop mags when i shoot it, lol. Now we both know when it comes to his Shield, the only difference is the shooter. So this is why i say the shooter has some to do with it.

 

[robkarrob]

This is not a shooting technique problem. Not to say your buddy wasn't causing his problem. There are loads of threads regarding the mag drops and S&W doesn't make a fix for operator error.

Bob

 

[Fabius]

Getting back to the OPs question, I suspect that the reason the .40 drops mags and the 9 doesn't is the additional frame flex from the more powerful .40 recoil.

 

[Smitty357]

Ok so, let me see if maybe I can add a little info to all of this. The mags are exactly the same same size (besides caliber). However, there is a design difference in them, but not a size difference.

The grooves along the sides of the mags are shaped different and also different lengths. I'll post the pics, so u guys can see what im talking about. However, i dont see where this could effect the way it works....Also notice the .40 short mag has the same grooves as does the .40 extended mag. The stories we here are all dropping the long mag. So once again, i dont see how the grooves can have an affect.

 

[robkarrob]

Smitty

I see the difference between the 40 and 9mm mags from your pics, the groove on the sides. The mag drop in the 40's was the mag catch slot problem. With all the threads about the mag drops, nobody can find the exact reason for the drops. Was it a mag catch or magazine problem. We know they were using two different mag catches. When removed from the guns, some were marked 1 and others 2. Without having both side by side it is difficult to find the difference between them, if any.

That is why I was asking the measurements width at the front of the mag, at the catch slot. It is difficult to measure, due to the taper. The outline tracing of the mag is the easiest way I could figure how to measure it, and get a reasonable correct measurement. Trying to use calipers or micrometers on the mag itself would vary greatly, due to the radius on the corners.

Bob