Glock 20 Loose Slide/Frame Fit

[Rick_F 5]

Greetings. I posted this on a Glock forum but figured I would get opinions here too. Recently got a Glock 20 Gen 4 and before I brought it to the range, I decided I would purchase a G19 as well. I spent a good amount of time looking over and dry firing both before I had time to test them out. They both had a slide to frame fit comparable to my other dozen pistols, and were near identical to each other. Last week I brought them both to the range, and put around 250 rds through the 19 and 100 rds through the 20. When I looked them over it home, I noticed the 20 become pretty loose. The rear of the slide clicks back and forth when I put lateral pressure on it, and it rattles around now (not the firing pin rattle) quite a bit, be it cocked or not, with or without magazine, and with or without a snap cap in the chamber. For polymer pistols, I have an HK P30, USP 45T, Walther PPS, & a FiveseveN. None of these are as close to being as loose, regardless of the amount of rds through them. I read a few posts about Gen 4 21s being loose, but what sets my case apart is that before I fired it, it was pretty tight. Now it rattles like a can of krylo n, while the 19 seems just as before. My 1911s and SIGs loosened a little after a lot of rounds, but this is a night and day difference. Does this seem normal? Thanks in advance for your input.

[Vicious 138]

If it shakes, it shoots. Play in a Glock is normal.

 

ETA: If it really feels that loose, check that the rails are still solidly in place. Never heard of a problem with them, but that's all I could see happening to cause an undue amount of shake.

[Rick_F 5]

If it shakes, it shoots. Play in a Glock is normal.

 

ETA: If it really feels that loose, check that the rails are still solidly in place. Never heard of a problem with them, but that's all I could see happening to cause an undue amount of shake.

Thanks for the reply. When I take the slide off, the rails don't show any movement. I am just perplexed on how it went from a standard slide/frame fit to noticeably loose after 2 boxes of ammo. Not knowing anything about Glocks, if it was initially that loose, I would have thought it normal. The degradation of fitment happened really fast. I guess there's only one way to tell if it's gonna get looser.

[Vicious 138]

Did you clean it before you went shooting? Maybe there was an abnormal amount of the anti-sieze compound on the rails making it feel tighter.

[Sandy 44]

I had an M&P 40 Pro series that was put together very loose. Being used to striker fired guns , I knew the different. Some play is normal , this felt absolutely loosey goosey. It shot well out of the box , but eventually ( after about 300 rounds)I was plagued with FTEs and FTFs. THEN I got it back ( replaced bbl ??) and a few thousand rounds later it went 3 burst auto on me.... Sent it back again , and Smith cited something about incorrect tolerances and a prematurely worn out sear , replaced the gun , which means I had to burn a permit. Grrr.

 

People will tell you rattling is normal , and it is. But if you have other polymer guns and are well aware of what it should feel like , and this one feels off , it probably is. Where did you get it?