Suppressing the M1A Rifle

[Arc Light]

So now that I have experienced shooting suppressed, I want to suppress everything I own I have two M1A's that I bought back in the 90's, a Scout model and a Super Match. I understand that the M1A was never designed to be suppressed, but I see plenty have done it. Some say it worked out great, others haven't been as happy. Have any of you guys done it successfully? Any tips you could share? I would start with my Scout model to see how it goes. From what I have read, I would need a muzzle thread adapter and possibly an adjustable gas plug. Anything else?

 

[CMP70306]

I briefly tried it when PA announced they would allow semi auto for deer, once they rescinded it I lost interest. The little bit of testing I did resulted in a bunch of gas to the face even with the gas set to the bare minimum for function using a SilencerCo Hybrid.

A can with better flow through could have better results but I abandoned the project and probably won’t pick it back up, not worth the investment to get it to kinda work right.

 

[Arc Light]

I briefly tried it when PA announced they would allow semi auto for deer, once they rescinded it I lost interest. The little bit of testing I did resulted in a bunch of gas to the face even with the gas set to the bare minimum for function using a SilencerCo Hybrid.

A can with better flow through could have better results but I abandoned the project and probably won’t pick it back up, not worth the investment to get it to kinda work right.

Did you use an adjustable gas plug like the one made by Schuster?

 

[J. W.]

Never done it, and I'm not sure how the muzzle adapter is made, but I would assume you'd need some castle nut pliers. There is a Schuster adjustable plug, like you mentioned, for regulating gas. Or you can just turn the gas off and have a single shot. Your gas piston and cylinder will probably need cleaning a little more often.

 

[CMP70306]

Did you use an adjustable gas plug like the one made by Schuster?

Yup, ran it down until it wouldn’t eject and that was the only time I didn’t get gas, if it would cycle then I was getting gas blowback. That’s most of what I remember as it’s been 5 or 6 years since then.

 

[Arc Light]

If I don't care about losing the front sight (since I always use a scope) I wonder if I could use this adapter and lose the castle nut altogether? https://www.smithenterprise.com/product/pn-2000a-m14-22-and-18-muzzle-adaptor/

 

[CMP70306]

The one I used had front sight block and I just swapped it over, pretty sure this is the one I used.

PN 2002: M14 Adaptor, Castle Nut Type - Smith Enterprise

Machined from fatigue proof steel bar stock. Includes wire EDM internal male splines and rectangular hole for the castle nut. Threaded 5/8"x24, with .735" length of thread, a common size that fits most other accessories. The dove tail deck will fit any USGI type front sight, including: P/N 2055...

www.smithenterprise.com

 

[Coffee_and_Pipes]

What about an OSS/Huxwrx can, or some other kind of flow through can? It seems like semi autos that are finicky about higher-back-pressure cans take to the flow through designs more readily.

I’ve been waiting on my permission slip to be approved for an OSS 762 can, so I don’t have any first hand knowledge, but they seemed promising enough to try.

 

[Plinker 73]

Didn’t like it on mine. Too much blow back and crud in the action and magazine with a Gemtech can. Still have the adaptors laying around the bench someplace. PM me for info if you want them.

 

[Arc Light]

Yup, ran it down until it wouldn’t eject and that was the only time I didn’t get gas, if it would cycle then I was getting gas blowback. That’s most of what I remember as it’s been 5 or 6 years since then.

If you still have the Schuster adjustable plug and want to sell it let me know.

 

[KYAggie]

I’ve done it without the Schuster. I got a Gaslock Front Sight made by SEI. Google .595x32 to 5/8x24 thread adapter M1A. Several places make them and they range in price from $30-$100; not sure why they should cost $100.

Most important thing is you need the shroud from a blank firing adapter kit. It will cut down on gas to the face, which is pretty bad.

This:

PN 2013: GLFS-D-18 Dovetail - Smith Enterprise

Deck height allows use of GI or match front sight. Chrome-moly, highly advanced metallurgical process. Double heat treated, as well as M80HT, corrosion resistant 60 HRC surface. For 18.0" barrel (i.e. MK14 SEI).

www.smithenterprise.com

Plus this:

M1A to 5/8-24 RH Thread Adapter - Black (Steel)

Convert the threads on your M1A to common 5/8-24 for the use of Muzzle Devices and other .308 accessories on the end of this popular barrel. This grade is made out of high grade black oxidized steel and contains two wrench flats.

www.infiniteproductsolutions.com

Or

PN 2002: M14 Adaptor, Castle Nut Type - Smith Enterprise

Machined from fatigue proof steel bar stock. Includes wire EDM internal male splines and rectangular hole for the castle nut. Threaded 5/8"x24, with .735" length of thread, a common size that fits most other accessories. The dove tail deck will fit any USGI type front sight, including: P/N 2055...

www.smithenterprise.com

Both need this:

Blank Firing Adaptor, with Case Deflector, GI, New, M14 / M1A

Your Source for Service Rifles: M1 Garand, M1 Carbine, M14 / M1A & AR Types

www.fulton-armory.com

 

[KYAggie]

I bet you could turn the gas valve and regulate the gas without a schuster.

 

[Arc Light]

I bet you could turn the gas valve and regulate the gas without a schuster.

I'm thinking you're right. That plug seems to be out of stock everywhere I've checked anyway.

 

[roostercogburn98]

YHM makes an adapter for their cans that allows you to keep the front sight as well. The barrel has 3 grooves under that flash hider, so don’t go twisting it thinking it will come off. That castle but actually “pulls” the cage off as you loosen it.

 

[PBWalsh]

What about an OSS/Huxwrx can, or some other kind of flow through can? It seems like semi autos that are finicky about higher-back-pressure cans take to the flow through designs more readily.

I’ve been waiting on my permission slip to be approved for an OSS 762 can, so I don’t have any first hand knowledge, but they seemed promising enough to try.

You’re going to enjoy that can, I like mine besides the occasional flashiness.

 

[Clayman]

If you want to suppress those platforms do yourself a favor and get an OSS/HUXWRX

 

[Clayman]

Iirc oss just teased the new 7.62 flow at shot show. I'd definitely grab that.

 

[Gustav7]

I would highly recommend looking up and watching Tony Ben's videos on the M1A rifles. He stopped doing youtube 2 years ago or so but he's still on Rumble and Parler I think. If it's been done to an M1a, he's probably knows how to do it.

https://www.youtube.com/@tonyben3/videos

 

[KYAggie]

^^^^^^^ Could not agree more. I’ve not see anything he did about suppressors specifically, but I haven’t see all of his stuff either. What I have seen and read of his is spot on and very informative.

 

[SharpsNitro]

I played around with suppressing the one I had (LRB M25). I used the DeltaP Designs adapter, I had to file down the edges of the slots a little as there was enough metal pushed up proud by the machining that it wouldn’t fit (Krieger CM barrel). Also used the Schuster adjustable gas plug. The original setting I had was nice and easy on the operating rod, the brass would land a few feet away at 3 o’clock. Biggest issue I had was with the scope rail on the M25, I would get brass caught between the op rod handle and the scope rings. Even upping the gas flow didn’t solve the problem, likely needed a small deflector on the mount or Ring to stop it from happening. Sold the rifle a few years ago so never resolved the issue.