My shooting partner had one when they first came out like 15 years ago. We ended up using a dremel to open the ejection port way up and then used epoxy to fill in the forward starboard (right) corner of the receiver to help guild the spent cartridges out. Otherwise the thing would stove pipe on all but the most expensive stinger rounds. We tried taking a coil out of the recoil spring too.

This was one of the first Tec-22's made and it along with it's brother's had a rather nasty and exciting problem - going full auto! If you gently squeezed the trigger the thing would let of double taps so fast that you couldn't hear the difference - only the shooter would feel and the target would reflect. Three and four round bursts were also pretty common. If you took a cigarette butt and put it behind the trigger you could empty the whole magazine. We use to shoot the thing at the San Diego police range and my buddy ended up lighting the thing up by accident and had the range officer looking at the thing pretty closely.

He noticed the dremel and epoxy work and thought we might have had at the trigger/sear assembly so he took it and with his typically jerky trigger action could never get it to spray. They were recalled for some sort of adjustments at a later date.