Kel-tec SU-16 Magazine Woes

[Dukes]

I bought an SU-16 and had to send it immediately back to the factory because of magazine feeding problems. I have it back now and it works fine with the factory 10-round magazines; however, it is advertized to take any AR-15 mag. All of the AR mags that I can find do not feed.

Gun shop people tell me to get "the military surplus mags". I ordered a pair from the Impact Guns website in Utah and received two "British Military" 30-round AR-15 mags that had Singapore stickers on them.

These did not feed either (from either side). Comparing the feed lips of the magazines it appears that the Kel-tec mags have a narrower opening and more anteriorly extending lips. Knowing that differences do not necessarily correlate to problem sources, I ask:

What do you all think is going on?

Has anyone else heard of this?

Can I fix it without sending back the mags from Impact?

 

[DMK]

I'd say it's still the rifle. You shouldn't be having problems with those Singapore mags.

 

[AK103K]

I had some problems with USGI mags when I got my SU-16. My factory mags worked fine and have never been a problem. I've never tried the British mags, so I dont know how well they work, although I have heard they have caused problems in the AR rifles, but again, no personal experience here. In my AR's the only mags I've had good luck with have been USGI mags and Colt mags, the rest have been iffy to terrible. I dont know if this will carry over to the SU-16 or not. The GI mags I have are mostly the "Adventure Line" mags from the 70's. These are the ones I had some minor trouble with in my SU-16. Minor trouble = about the first three rounds from each mag. The bolt carrier was hitting the top of the mag and it took about three rounds for it to "wear in" and after that, they have worked fine. Here's a pic of the top of the mags:

The bright spots on the corners at the rear of the mag are where it was hitting and wore away material from the mag. It was more just a heavy scrape. All the Adventure Line mags hit in the same place with about the same amount of wear. My Colt mags work fine, but they have a different profile of the rear of the mag and of the feed lips and I think this may be some of the problems or no problems. Another issue may be slight differences the position of the mag catch hole and how it positions the mag in the well, but thats a guess on my part. Heres a pic of the rear of a Kel Tec mag(L), an Adventure Line mag(C), and a Colt mag(R):

As you can see, there are differences in the way they are made, although the Kel Tec and Adventure Line are very similar.
When you say your having trouble, is it because the bolt carrier is not going forward? This was the main problem for me. If it is, you may want to try one mag and if you see where it hits on the rear of the mag, keep hitting that area with a file until it clears, if it doent appear to be to much. I dedicated two of my mags that work to my gun. I dont really like the larger mag in the gun anyway and prefer the factory mags, but I do keep a loaded 30 rounder in the stock as it makes the rifle balance better and I always have ammo on the gun. It would be nice if they all would work without having to fiddle with them, but I guess its just going to be one of those things you need to fiddle with until you find something that works.

 

[FrankGrimeyGrimes]

I have a low number SU-16 (No. 013X) and had similar mag problems when using 30rd steel SA80, USGI Labelles, and the new design Bushmaster 10rd mags (the KT 10rd mags worked just fine). These mags all worked reliably in my Bushy 16" carbine, so I knew it wasn't a mag issue.

Most of the feed issues involved rounds on the left side of the mag failing to load into the chamber.

Figuring it was a teething problem related to a new design, I spoke to the folks at Kel-Tec, explained the isssues and even sent the gun back to them with 2 examples of each magazine described above (with explicit instructions not to touch or modify the magazines). I got the rifle and my mags back within two weeks. The listed repair on the work sheet was "polished feed ramps". Now my SU-16 works reliably with all my mags and ammo.

Hopefully as KT goes further along with production, the mag feed problems will be remedied.

 

[Dukes]

Thanks for the advice!

In the balance, it looks like the best thing to do is send the rifle back one more time with the new magazines.

The feeding problem seems to come from the angle at which the cartridge is delievered to the feed ramp. The bolt carrier does not hang up on the magazine. The KT mag seems to point the shell more toward the center of the breech than the Singapore mag.