I have an Ithaca Model 51 featherweight 20 gauge in my shop for repair. When you fire the shotgun the bolt does not move and eject the shell. The shell stays in the chamber. When you cycle the bolt to the rear it extracts and ejects the empty shell with no problem. Here is a list of the following actions I have taken.
1. Watched the shotgun expansion with Mr. Dunlap detailing the Ithaca model 51
2. Found that I was missing the gas cylinder retaining pin, fabricated my own and fixed that problem.
3. Removed gas cylinder piston and inspected it for burs damage etc., no damage. Cleaned gas piston.
4. Inspected gas cylinder, there was no damage and gas ports were lined up with gas ports in barrel. Discovered there was only one gas port hole in barrel. 5. Reconfirmed there was only one gas port in barrel by using a bore scope.
6. Scratched my head thinking the 20 gauge model only had one gas port drilled in barrel from factory, even though gas cylinder has two gas ports drilled in it.
7. Cleaned the one gas port in the barrel and gas cylinder and verified they lined up and had no obstructions.
8. Reassembled the gas system and shotgun. Test fired the shotgun with an estate low base 20 gauge shell. Once again met with negative results, no extraction or ejection.
9. Watched the Shotgun expansion with Mr. Dunlap again in case I missed something. This also met with negative results.
10. I checked the internet for the possibility someone else had the same problem, once again met with negative results.
So hopefully the experts here can help me out with this problem. Does anybody know if Ithaca only used one gas port on the 20 gauge model? The shotgun cycles smoothly by hand and extracts and ejects with no problem. What am I missing? Any help would be greatly appreciated.
Answer
Piston seals? Gas leaking past the piston? Sounds like gas is not pushing the piston for whatever reason, so it is either not enough or escaping somewhere. But if it was simply not enough, I’d expect a short cycle and not a complete failure to move. Jeff
Question Follow Up
I checked the schematic and there are no pistol seals I can find on the parts list or schematic.
A lot of 20ga guns use only one gas hole………I don’t know about the Ithaca, but it sounds like that is the case with it. Not opening at all means the piston, gas cylinder are not doing what they are supposed to. Now as to why hard to tell. Did you put tape behind the op handle to insure it isn’t moving just a little bit? Just checking. Ken
Reply
I figured it out, should have tried this in the first place. The cheap Wally World 20ga. shells I was using were to low velocity to cycle the action. When I bumped the velocity up to 1275-1300 fps, she cycled like a champ. So note to self, from now on try numerous velocities after verifying everything is mechanically correct “and should work” LOL. Chris
