I bought my oldest son, 12, a Rossi 20 ga./.243 combo about a month ago for his first deer season. I put a scope on it and a hammer extender to allow easy cocking with the scope so close to the hammer. The first time we took it out to sight in the .243, the gun worked fine. Later, I tested the 20 ga. and it worked fine as well (heavy recoil). A week later, I took the .243 out for a final check (day before deer season) and the rifle wouldn't fire a round. It was "light Striking" the primer.
I tore the gun apart, cleaned it and tried everything to get the gun to shoot... no luck. A friend of mine happened to have a Rossi muzzleloader in his truck, so I tried to fire the weapon with his lower receiver... still no luck. The last thing I tried was removing the hammer extender, thinking that might decrease the weight of the hammer and speed up the strike... worked like a charm. I fired about 10 rounds with no failure. When I put the extender back on, the gun woudn't fire again.

First day of season, my son and I finally spot about 10 deer on a ridge. After a struggle, he gets the rifle cocked and aims in on the biggest deer about 70 yards away. He applies a slow steady squeeze... click. Luckily the deer were still looking at us, so he recocks the rifle. This time the rifle fires and he puts a textbook heart shot on a nice doe, who drops after about 3 steps.

Needless to say, this gun will not be going back to the woods with us. I am now eyeing the .243 barrel as a jack handle for my 12 ton hydraulic jack. It looks plenty sturdy for that task. I sincerely hope you have better luck with your gun.

Semper Fi, George