AOSC Forum Archive

I've got a King Arms M4 that has a firing problem. Every 6th or 7th shot or so is coming up short, both in semi and auto. It's like there's an air nozzle or tappet plate problem or something. Anyone care to shoot me some ideas?

Update: Sporadic firing. Please help...

It might be that your bucking isn't sealing 100% You might need to do some compression tests to check to see if there are any leaks, because it also sounds like it might be a leak somewhere.

It's not the bucking for sure. It might be an o-ring sealing the hop up, but I replaced the stock bucking after it started with a 2GX, and it's still doing it. It's a major disconvenience because of there being no internal connectors to separate the two receivers without clipping the Deans. Hmmm.... I might reexamine the hopup and see what I find.

Have you tried different mags?

Yes I have. Four different varieties. I'm going to disassemble it soon and check all of the internal piston and cylinder assembly seals and see if one of them is defective. It has to be. This is just a crying pain...

How would I perform a compression test?