National Match Gas Cylinder

[Adamg_55]

So I ordered a National Match Gas Cylinder from brownells. I took the old one off and now I'm trying to get the new one on. It won't slide all the way into place, it stops with about a 1/2 inch space left.

How hard should i have to bang on this thing to get it into place? I just don't wanna break anything.

Any help is appreciated.

Thanks,
Adam

 

[yomomma]

Just replaced mine. Although there were a few burs on the new gas cylinder which interfered with mounting, once deburred putting it on was no problem.

 

[Adamg_55]

Just replaced mine. Although there were a few burs on the new gas cylinder which interfered with mounting, once deburred putting it on was no problem.

How did you go about removing the burs?

 

[Adamg_55]

Als0 on an unrelated note, what size roll pin will replace the one in my oprod guide?

 

[Pop]

Als0 on an unrelated note, what size roll pin will replace the one in my oprod guide?

I'll pass on what Hungry told us at the Dundurn clinic: the holes aren't all a uniform size so the best thing to do is to buy a box of assorted roll pins from Princess Auto (or the equivalent) and pick out one that fits the best.

 

[yomomma]

I have an assortment of needle files, $10 from princess auto. Take your time. I must have put it on and taken it off at least a few dozen times. If you have a digital/dial caliber kicking around measure everything and compare to specs.

 

[mikebaker1129]

Als0 on an unrelated note, what size roll pin will replace the one in my oprod guide?

The USGI M14's use a 1/8 X 3/4 Long roll pin. The M305's use metric pins,but when I converted mine, I used all USGI standard size pins and have not had a issue.
Hope this helps...

 

[45ACPKING]

What Mike said
The only USGI roll pins that don't readily fit your chinese action are the bolt stop and mag release pins. All others are good to go

For fitting a gas system that is hanging up from a misaligned , welded on gas band plate.... I use the dremel sanding drum to deburr and polish the affected area. Needle files are also a good tool but may take longer.
Having to seat the cylinder with a small hammer on a block of wood is desireable.

 

[Adamg_55]

Ok, so I got it on, man is it tight!

Second question, can I use my norc piston in the new gas cylinder? Or do I have to buy a new piston as well? If I have to get a new one where is the best place to source one?

 

[yomomma]

You can use the old one if it fits. Read somewhere they were a little oversized.

 

[mikebaker1129]

I would purchase a USGI spec piston from Brownells (Most likely eill be SA inc) or from Sadlak or locate a take off USGI piston,they are still fairly cheap for $10-15 ea.

 

[ilikeoldguns]

By calling it national match, I assume these gas cylinders somehow increase accuracy?

 

[Rocket Surgery]

By calling it national match, I assume these gas cylinders somehow increase accuracy?

Only if you make videos about them on the internet

 

[Repro77]

By calling it national match, I assume these gas cylinders somehow increase accuracy?

From sadlak.com: IMPORTANT: THE NATIONAL MATCH GROOVE IS INTENDED FOR NM GRADE AMMO ONLY AND IS NOT RECOMMENDED FOR
SURPLUS BALL AMMO OR OTHER LOWER POWER AMMO.

If you plan to shoot NM ammo then the groove in the piston is
useful. Otherwise, it was not intended for regular ball ammo (not
enough power). The groove provides a more consistent pressure
against the op rod by bleeding off some of the excess pressure
inherent in high-power Match ammo. This results in a slight recoil
reduction to help "get back on target" during rapids. It also breaks
the vacuum between the piston and the cylinder allowing the
shooter to hear the piston slide down to confirm it isn't fouled.

 

[Rocket Surgery]

Man I'd love to see a chinese knock off win a shooting match