Norc Parts in a USGI Gas Cylinder

Wildcard91

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I'm thinking of swapping out my gas cylinder to make use of a sadlak piston,
besides the gas plug/nut what else needs to be replaced in order to make it work? Will the stock Norc/Poly gas spindle valve and spring work with the USGI cylinder?
 
I am not sure if the Chinese spindle valve will work in a USGI spec gas cylinder. If you have a Chinese barrel, you will need to use the Chinese gas cylinder lock, which usually works with the USGI gas cylinder and USGI cylinder plug. The Chinese barrel band should work with any gas cylinder.

I am not sure, but I think that at one time Sadlak offered Chinese specification titanium coated gas cylinder pistons.

Be sure to get some gas cylinder shims to adjust for proper pot alignment and gas cylinder lock torque.
 
I am running a sadlak tin coated gas piston in my
norc short rifle,no mods to use it.My oprod guide
has been redone,I am using a match oprod spring
guide and a spring from hungry.Gas system is stock
except for the piston.Shoots fine.
 
I am running a sadlak tin coated gas piston in my
norc short rifle,no mods to use it.My oprod guide
has been redone,I am using a match oprod spring
guide and a spring from hungry.Gas system is stock
except for the piston.Shoots fine.

Mine works as well, but as a rule it's not supposed to work. In theory you can wind up with issues with short stroking and whatnot.
 
I put a caliper on it when I got it and the same with norc
stock piston,and decided to try it as they looked and
measured the same.Maybe I got lucky,it happens some
times.LOL
 
Haha me too, when it came up at a m14doc clinic everyone was confused how it wasn't giving me problems. But no hiccups yet. If it works giver
 
Hey, I should look into that .... I do have a Sadlak TiN coated gas piston and a Norc gas cylinder to do this. Now I have to did through my vehicle and M14 tools while on the road right now. Thanks for the heads up.

Cheers,
Barney
 
I originally tried it in my Norc gas cylinder and had no problems either. I was firing boxes of federal and winchester and the piston alone seemed to shave 1 moa off all my 5 round groupings at 100m. It wasnt until I switched ammo to Hornady Superformance SST 168gr ammo that I started running into short stroking problems every 1 out of 7 rounds or so. It kinda makes you feel like your #### will potentially shrivel up and fall off.

I've measured the Norc gas piston and it's diameter is exactly 0.5005" just forward of the gas hole. The Sadlak Tin Piston measures 0.4975" in the same place. Considering that the interior dimensions of a USGI cylinder[ is 0.5006/.5000, I'm wondering how a USGI cylinder will function with my TiN piston with Hornady ammo.

This will officially be the last thing that I do to my rifle in terms of accurizing it, as I'm already getting 1-1.5" groupings at 100m off bipod and prone using 150gr factory ammo. I dont forsee any need for me to bed the rifle and if I wanted tighter groups I'd get a bolt gun or start reloading.

I already know that I'll have to use my norc gas lock, but I was just wondering if I would need to tack on a USGI spindle valve to my gas cylinder and gas plug order. If anyone knows if a chinese gas spindle valve will work in a USGI cylinder that would save me an extra $20 in parts and $40 dollars in carrier brokerage fees. It would also be pretty interesting if someone could come up with a way to mic the inside of the Norc Cylinder.

Cheers
 
If you are using a norc barrel, you need to retain the gas lock. If you use a GI cylinder, you need to also, as a minimum, replace the gas plug. I would also replace the gas spindle, spring and roll pin. This is because the GI parts are stainless and the Norinco parts are not. Also, some of the chinese spindles I have tried would not fit a GI cylinder due to tolerance issues and the GI spring and rollpin are inexpensive and better made than the Chinese ones.

WRT pistons/cylinder fit - it's trial and error. GI and US-made cylinder and pistons are interchangeable. The Chinese stuff appears to have a broader tolerance range and somestimes they fit well, other times not. I have had chinese pistons bind in GI cylinders and vice-vera, but usually if you swap a few around you can find a pair that works and also passes the vaccum test - assuming you have enough parts to try.
 
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