Jennings .22lr

Well, the reason for that is that the gun is just not very well made. It is basically a Saturday night special. What you are experiencing is completely normal with a Jennings, they are usually finicky with ammo.
There have actually been occasions where a .22 Jennings has gone full auto on someone. The best thing to do if it does that is get rid of it, fast. A lake usually works well for this. Also, never speak of it again. The BATFE wouldn't hesitate to throw someone in federal prison for a very long time, regardless if it was your fault or not that it went full auto. I'm not saying it will go full auto on you, I'm just saying it's possible. Most won't ever go full auto.
As for fixing it, maybe some of the gunsmiths around here would know what you could do.

 

With a gun like the Jennings, if you find an ammo that works well just stick with it. It's not made for a lot of shooting and you lucked on which one works already. As far as gunsmithing I always avoided them in my shop because no matter what I did to the gun, even just replacing a grip screw, when and I do mean When something went wrong I had worked on it. There's no winning on a gun like that.

 

I have a Jennings J-22. It mostly just sits in the safe. It will cycle Mini-Mags, Stingers and Velocitors fairly reliably. Do not carry it around with a round in the chamber. That would be very unsafe. I do not use mine for anything other than plinking at the range. The cleaner you keep it the better it will work. If I was you I would save up for something a little better. If money is tight you could look at a High Point. I would not be surprised to see a used one for $100. High Points are cheap but actually good guns. Your Jennings can be fun until you get something better. Be sure to wear eye protection.

 

Jennings- bryco/ jiminez firearms, otherwise known as "saturday night specials" and "throw down guns". They are one of the worst guns ever made,and are known for their catastrophic failures. It would be more expensive getting the gun fixed then it would to just to buy a new one "not a jennings". Im not being an azz, its the truth.

 

I don't know about the Jennings, but my PPK/s requires HV ammo.
Standard velocity does not have enough power to overcome the mainspring reliably to cock the hammer.

Understand that the problem is not normally with a rifle. The longer barrel provides a higher velocity than the short handgun. Some handguns are designed for standard velocity ammo.

As said before, find the one that works and stay with it.

 

I have a Sig Mosquito that's very picky on ammo. CCI Mini Mags cycle well and almost nothing else. Some guns are just picky

 

The gunsmith at the LGS that I work flat out tells people that working on a Jennings is a losing proposition. He won't take them in for repair. Just not worth the headache.

 

That's been my feeling on them since the first one showed up on my bench in the early 80's. I won't even take them in trade because I wouldn't be willing to sell it to anyone!

 

Is the Jennings one of those jewels that have plastic internal parts?

 

If the old jennings is like the jeminez. My buddy got pissed at it jamming so we took it out and shot about 400 rounds threw it. It swelled the slide and he hasn't had anymore problems since.