.30 Carbine piston problem

[Boondox]

AND almost forgot to mention ... FWIW .... you keep putting that on and taking it off a lot ................ you may find she doesn't tighten up like it used to .......and all the more reason for something to be used.
I'd do it once and let it be ..... but I understand some have the need to clean and what not

[Boondox]

Checked the number for you ... in loctite ............... 243 is the number you want

[Gunsnwater]

I can understand that an under-powdered cartridge might send the operating rod only partially backwards, not enough to extract, but once in a while the rifle fires and that's it. No action at all resulting from gases or recoil.

I have the proper wrench, have removed the piston nut and piston, cleaned the port (which actually seemed clean, as well as the piston cylinder). The piston appeared in nice condition.

I figure one of two things are happening. One possibility is the piston is able to cock occasionally and "wedge", with no force transferred to the operating rod, although the tolerances seem tight enough to preclude that.

The other would be the bolt remaining in battery and locking up against any cam action.

This fired case remaining in chamber happens approximately once in a dozen or so rounds, and not at all at other times, so it is pretty random.

Actuating the operating rod manually at various (by hand) speeds does not result in any wrong results.

Not sure what to look for or how to test for it. Help!?

These are my own handloads. They are each carefully weighed at 15 grains H110 (max).

I am not talking about weak cycling. I am talking about bolt remaining unmoved during and after discharge. A lack of piston action, occurring occasionally.

As it turned out, the piston retaining nut had come loose. I have the wrench. Super-cleaned everything involving the piston system, installed the retaining nut tightly and all is well. Thanks to all for responses.

Also, bought the bolt tool. Shopping pays bigtime. $50 plus from Amazon, $23 and reasonable shipping from SARCO.

See now the 1st post says you took out the piston so how did you miss the nut being loosened? Good job figuring it out.

[Bang]

Good catch. First post, it hadn't come loose. Next time it happened, it had (likely that I didn't tighten it enough when reinstalling it). Now I'm wondering if I have found the cause! Time will tell.

[Bang]

Checked the number for you ... in loctite ............... 243 is the number you want

Thanks. I'll try it. And Permatex makes sense, it being designed to deal with hot engines.