DIY USA Glock 17 Magazine Modification

Rocky Mosasaurus

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Dear NES community members,

I recently went to the range and had a problem with my USA brand G17 18 round magazines. They have a lip at the front of the base plate that juts out into the mag well. At one time this lip may have been soft and malleable...but over time the lip hardened and it will prevent any operator from successfully inserting and removing their magazine. At the time I stubbornly jammed the magazine into the mag well until it fit snuggly. However, after running a magazine without failure and hitting the magazine release my magazine would not eject properly. I had to remove my slide, a range supervisor came and pulled the frame off the firing line, he lubed up the magazine in their shop on site and popped the magazine out. With USA mini-14 magazines I ran into a problem with feed lips...but this time I knew there was a simple solution and I was determined to conquer my phobia of USA magazines. Below you can see side views and a front view of the problem at hand.

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I decided I would cut the base plate lip off, allowing the magazine to fit flush into the mag well. If you are planning on making this modification please be very careful. I will let everyone know the following: I did not use a normal knife: I used a soldering blade to saw through the plastic feed lip. This actually turned out to be a difficult process...the soldering blade was quite small and I did not use a vice to secure the base plate because I had to complete the cut on my front porch so it would not stink up the entire house of plastic. This meant I had to keep switching grips to avoid nicking my fingers with the blade. My soldering knife broke in the process and I had to finish the job with a cheap but sharp karambit knife I ordered online awhile ago. But the result came out great and I filed the remaining plastic down with a metal file.

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Here you can see the jutting lip of a factory magazine:

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Here you can see the flush fit of a modified magazine:

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Anyway, I told some people I was going to cut the plastic feed lip off of one of these magazines on a thread regarding preban square notch mags that sold for $180 each. As an aside, I wish the buyer nothing but success with those magazines and I am happy for the seller for making some good cash as a result of their sale. But this thread is for people who may want to save some money and modify their USA brand magazines into decent range magazines. I will follow up and let people know how the magazine functioned at the range within a couple weeks. Thank you all for your time and again please be extremely cautious when carrying out this modification.

Best Regards,

Ben
 
What purpose did that nub have in the first place?

Been looking at some USA Mags. Haven't pulled the trigger yet due to all the so-so reviews (to put it lightly), but they are temping due to price point. I figure I'm good with modding things, so maybe I can get them reliable.
 
What purpose did that nub have in the first place?

Been looking at some USA Mags. Haven't pulled the trigger yet due to all the so-so reviews (to put it lightly), but they are temping due to price point. I figure I'm good with modding things, so maybe I can get them reliable.
I think the nub originally had a little give to it and served as an adhesive material for the polymer frame of the Glock and the steel body of the magazine in order for the mag to fit snuggly. However, USA went out of business before 1994 and I believe over time this material hardened and could no longer could serve its intended purpose.

That being said, I feel like this modification process could have been completed with other tools as well, maybe a small hand saw of some kind. The soldering blade did produce a really nice cut and filing the remaining jutting bits off with a metal file should conclude any persons mod steps.
 
I think the nub originally had a little give to it and served as an adhesive material for the polymer frame of the Glock and the steel body of the magazine in order for the mag to fit snuggly. However, USA went out of business before 1994 and I believe over time this material hardened and could no longer could serve its intended purpose.

That being said, I feel like this modification process could have been completed with other tools as well, maybe a small hand saw of some kind. The soldering blade did produce a really nice cut and filing the remaining jutting bits off with a metal file should conclude any persons mod steps.

Given the smaller body dimensions of the USA mag (just a steel vs polymer/steel sandwich thing), I wonder if it provided forward/aft stability to ensure the mag didn't rock in the mag well. Kind of like what the side fins are doing for lateral movement.
 
That would also make a lot of sense. As it stands the mag does wobble slightly in the mag well. I plan on taking it to the range this weekend or next to find out how it functions once and for all because I want to find out which mags I am going to be comfortable with using in my Glock 45 as an every day carry and which ones I should designate range mags.
 
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glock intentionally employs a polymer magazine catch. it is designed to function with polymer magazines
if one insists on running metal magazines i would keep an eye on your magazine catch as it will almost certainly exhibit accelerated wear
if your metal magazine is getting stuck, i would be concerned about peening or digging-in against the magazine catch, or some other internal damage to the frame

regarding the nub on the baseplate, that was probably designed to interface with the gen 2 pistols (these had a cutout in the front of grip) although i'm speculating.
i would be very cautious using these mags to avoid over-insertion, as a metal magazine getting over-inserted can damage the ejector or ejector housing

the central element of glock reliability is their magazine. when one deviates from glock OEM mags, nothing good comes about.
the capacity argument is out the window. while a 10 rd mag limit is unconstitutional, I need 10 rounds that cycle reliably more than 17 that might fail me
 
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glock intentionally employs a polymer magazine catch. it is designed to function with polymer magazines
if one insists on running metal magazines i would keep an eye on your magazine catch as it will almost certainly exhibit accelerated wear
if your metal magazine is getting stuck, i would be concerned about peening or digging-in against the magazine catch, or some other internal damage to the frame

regarding the nub on the baseplate, that was probably designed to interface with the gen 2 pistols (these had a cutout in the front of grip) although i'm speculating.
i would be very cautious using these mags to avoid over-insertion, as a metal magazine getting over-inserted can damage the ejector or ejector housing

the central element of glock reliability is their magazine. when one deviates from glock OEM mags, nothing good comes about.
the capacity argument is out the window. while a 10 rd mag limit is unconstitutional, I need 10 rounds that cycle reliably more than 17 that might fail me
Well now the nub makes a lot more sense. With old frames the magazines would have been perfectly compatible.
 
Good news and bad news. The magazine functioned fine but my front sight popped off and my factory 10 round mags wouldn't work so I don't know if my Glock is malfunctioning but I am planning on sending it in to the factory to make sure everything is okay.
 
I just sent my Glock 45 into the factory so I'll let you guys know if anything undesirable happened to it in the process of trying to make the Glock accept these weird magazines.
 
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