USGI/Norinco interchangeability question.
- Thread starter Stevo
- Start date
Another in your long, long line of unhelpful posts.
Other than the gas lock and castle nut everything can pretty much be swapped between rifles.
I know some members here run a sadlak piston in their norc gas assy. I would check for fit and function before firing, a caliper would not be a bad idea.
I know some members here run a sadlak piston in their norc gas assy. I would check for fit and function before firing, a caliper would not be a bad idea.
Thanks, Simon.
Could I mix that with some bourbon first?
Generally NO
As mentioned , there a few rare exceptions.
Even though it works in the odd rifle, here's why I don't advise it.
G.I. Spec pistons are generally smaller diameter than chinese.
Running an undersize piston, even if it works, causes "piston chatter". Meaning the piston can rattle around as it cycles.
Over time, piston chatter will wear out both piston and cylinder walls.
Piston chatter also causes vibrations that I suppose, could also affect barrel harmonics. But in that area I'm only assuming
Overall, not desireable hehehe
Thanks. That may explain a comment another member made to me.
Does a GI piston have any markings which would differentiate it from a Chinese or a spec diameter to measure? My old rifle has some GI parts, but put on by the previous owner, so I don't know if the piston was swapped out.
Does a GI piston have any markings which would differentiate it from a Chinese or a spec diameter to measure? My old rifle has some GI parts, but put on by the previous owner, so I don't know if the piston was swapped out.
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In my reading I have learned that stocks can be swapped with a few small modifications, the area where the tripper assembly slides in is a bit different. My concern would be the thread pitch on items such as muzle breaks because as we all know the USA had to be different and not come over to the metric side. But again that is just what I have heard. I am not lucky enough to have a USGI M14 and a Chinese one.....yet.....
You can tell by visual inspection. If you wish, send me an e-mail for a close up comparison photo of Sadlak, commercial SA, Inc., USGI, Smith Enterprise, and mainland Chinese gas pistons side-by-side. leeace99@hotmail.com
For the most part it should work.
Simon is correct. The gas lock and the castle nut are the only two things that will not work because they are threaded using metric as opposed to imperial threads. The gas cylinder and piston on the Norc are ever so slightly oversized by a couple of thousandths of an inch. This is so marginal that a USGI piston will usually still work in a Norc cylinder. There is nothing wrong with the Norc piston and Norc cylinder assembly to warrant a replacement to USGI parts. If it aint broke and she passes the tilt test, just get out to the range and shoot her.
When I swapped in my Sadlak TiN NM non-grooved piston, it would work as well, but short stroking became an issue once out of every couple of hundred rounds. I did find that my groups shrank marginally by about .5" @ 100y after this mod.
Simon is correct. The gas lock and the castle nut are the only two things that will not work because they are threaded using metric as opposed to imperial threads. The gas cylinder and piston on the Norc are ever so slightly oversized by a couple of thousandths of an inch. This is so marginal that a USGI piston will usually still work in a Norc cylinder. There is nothing wrong with the Norc piston and Norc cylinder assembly to warrant a replacement to USGI parts. If it aint broke and she passes the tilt test, just get out to the range and shoot her.
When I swapped in my Sadlak TiN NM non-grooved piston, it would work as well, but short stroking became an issue once out of every couple of hundred rounds. I did find that my groups shrank marginally by about .5" @ 100y after this mod.
