I have a Tanfoglio TA-90 in 9mm that I picked up for a good price sometime back. The guns shoots well enough but i have a problem with the slide catch engaging when it shouldn't i.e. when there are still rounds in the magazine. It typically hangs up every three shots or so but on occasion may hang up every shot. The slide remains to the rear but will readily strip off the next round and return to battery when the slide catch is pushed down. I can hold the slide catch down and it will perform flawlessly with no stoppages of any sort. My thumb is not inadvertently pushing up on the catch. I've double checked this.

I had an 18 lbs recoil spring in there and thought this may somehow be part of the problem. Went back an put in a new 11 lb spring which is the factory weight. No change.

The tab on the catch looked to be a bit long and I thought maybe it was catching the round coming up into the top position. I trimmed the tab a bit but this did not stop the problem. I pulled off the slide and inserted a loaded magazine. It does not look like the tab is engaging any of the cartridges.

The slide catch spring does hold the catch down with some force. The force is not as strong as on my Baby Eagle in 9mm but it "seems" strong enough to prevent the catch from jumping up and engaging the slide to hold it back as result of recoil forces.

Your ideas about cause and or possible fixes are appreciated.

Eric

99 percent of the time this happens is improper hand position.

One of your thumbs is contacting the slide stop causing it to ride up and engage during recoil.