Glock 20SF Misfiring [Archive] - Glock Talk


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06-08-2010, 16:57
I bought a new Glock 20SF about a year ago and have put about 500 rounds (both my reloads and factory) through it without a single problem. Last week before shooting, I decided to install a scherer 3.5# connector. Installed it, shot it a couple of times, did not like the feel of it, so I put the factory connector back in. Within twenty shots with the factory connector back in, it misfired (striker did not hit primer hard enough) three times. The striker indent appeared to be higher than normal and noticeably less indented. This happened with both my reloads with CCI 300 primers and a some blazer ammo. I have cleaned it inside and out since the first time, and it still misfires about one in ten shots.

What did I mess up, and how can I fix it?

Thanks in advanced.

06-08-2010, 19:06
I have no idea why the CCI would fail but odds are the failure on the reload was caused by a swelled case head. The swelled case did not fully chamber and the barrel was held slightly open, otherwise known as "out of battery". The high primer dent is telling you the gun was not in full battery when you fired.

06-09-2010, 06:46
Any explanation for the misfire on the factory ammo? Possibly carbon buildup inside the chamber not allowing some rounds to chamber correctly? Just thinking out loud.

I just want to be sure I did not mess anything up while taking the gun apart. This was the first time I took the trigger assembly of this gun apart, and right after it started misfiring.

06-09-2010, 09:36
If you were shooting lead bullets prior, I would suspect a build up at the chamber mouth. This could hold the factory ammo out far enough to stop lock up.
Are you cleaning the barrel before switching ammo? It is real important you clean the barrel before switching from jacked (or plated) to lead bullets.

06-09-2010, 10:25
Never shot lead bullets through it, although recently started reloading rainer plated bullets for practice rounds. Have shot about 100 rounds with them. I have cleaned the barrel, but maybe missed something?

06-09-2010, 18:17
Once again, I suspect a swelled case head is the culprit for the reload FTF.