Glock 20 Malfunction Question - Please Help

[Anthony]

Hello Everyone,

My Glock 20 is having a couple of malfunctions that are occurring more frequently than I would like. Could someone give me some help in diagnosing the problem?

The gun is entirely stock except for the Arotek extended slide release I installed onto the gun when I bought it in 1999. It is one of the models with finger grooves, but no rail.

Using full capacity, factory 15-shot magazines I am having the last round and occassionally the next to last casing of the magazine either get caught on the extractor and not eject or (more commonly) wedge itself perfectly in the center part of the top of the ejection port with half of the casing in the gun and half of it out.

Last weekend out of 150 rounds fired I had 2 of the ejector style malfunctions and 3 of the wedging style. It has had this problem with a range of loads and more than one magazine. Plus, the gun was well lubricated with oil on the rails and on top of the barrel when these problems occurred last weekend.

Am I doing something wrong? Weak mag springs? Weak recoil spring?

Can someone please help?

 

[Vitamin G]

If it wasn't doing this before the aro-tek release, i'd swap it out for stock and see if that makes a difference. Beats me how, but the interaction of parts is like quantum physics and women. I have no idea how they work.

 

[Lennyjoe]

When was the last time you changed springs? I'd say for starters change out the mag springs and put in a new recoil spring. Most likely it's the mag springs but since your gonna change them might as well do the recoil spring too.

I suggest using Wolff springs.

 

[dmallind]

I'm no Glock armorer but I'd be inclined to go for the recoil spring and mag springs too. Certainly the timing of the cycle is being screwed up somehow. I'd probably be MORE likely to go for recoil spring, perhaps compunded by slightly weakened mag springs, being the main culprit but agree with Lennyjoe that, with low the price of replacing both, do both. I would however be tempted to do one first and see if that cures it, then if it does still replace the other as normal maintenance but you have the culprit definitively identified for next time/next gun.

If you haven't changed the recoil spring since 1999 you definitely should consider doing so anyway. They don't fail that often but it's a bugger when they do.

 

[PO2Hammer]

Recoil spring would be my first guess.
I used to have a G-20 and I started to have problems as soon as the full capacity magazines were available.
With mine (and several others on GT), the rounds in the mag would not come up to the feed lips properly, and the slide would hit the side of the cartridges, not the rear, causing jams.
It always worked 100% with 10 round mags.