old jeff

I have shot maybe 400 rounds of factory 9mm through my STI Target Master. Last week after firing the last round in the mag (by count of shots), the slide locked closed. So tight I couldn't budge that in the field. I removed the mag and saw no problem with that. The slide would move back about 3/4" (not accurately measured) and the barrel dropped down a bit so I felt the link was pulling properly out of the lugs.

I went back to my shop and used a brass rod and tapped smartly. I had counted the rounds fired and knew there was no round in battery and that was confirmed when the slide opened up. The slide freed up and worked perfectly. I disassembled and check all the components and saw nothing out of ordinary. Cleaned and lightly lubed the pistol and later fired 8 rounds to check function. Every once in a while the slide will still "catch" a bit but not tightly.

I did remember that the slide started not staying open after firing the last round prior to this lock up.

What do you all suggest happened. I will NOT send back to the factory, so how about some pointers.

I am just wondering if the mag is at fault.

Thanks for helping a new guy to this forum

danf_fl

Do you have other mags?
That would be the first thing.

Are there any "galling" marks on the rails?
Are the rails straight?

old jeff

I looked at the rails and slide and could see nothing out of order. The same gap all the way in the slide.

I had been thinking about using a different mag to see what is up.

Thanks for getting back to me and I appreciate your help

Jeff