Project: Silenced M1 Garand

[NICKT93]

Will be very cool once complete

 

[Zellybob]

I’m debating suppressing my Garand, but nervous about the 1/2 threads. Have you had any issues or advice now that you did yours?

 

[Zellybob]

Here’s the route i’m thinking of taking for a suppressed Garand. 308 Mini-G Garand. Use afulton gas lock thread adapter with the tread adapter machined off to create a shoulder.

With the modified gas lock installed on the barrel, cut a 1/2-28 thread in the barrel and match finish machine the shoulder in the gas lock. Then install a 1/2-28 to 5/8-24 thread adapter. This creates sufficient spacing for access to an adjustable gas plug.

Then install the suppressor
+

I’m thinking the OSS suppressor for the low blowback. I’m thinking all this should work. Just still agonizing about the 1/2 thread in the barrel...

What has been the forum’s experience with 1/2 threads on 308 sized barrels?

 

[Zellybob]

The assembly:

 

[Zellybob]

OP, any advice/lessons from your project?

 

[laf]

OP, any advice/lessons from your project?

I don't trust tolerance stacking that much on the thread adapter. If it was just a brake or flash hider you're putting on then sure, but a $1,200 OSS can and then a few months wait if you punch a baffle or endcap and it needs service wasn't worth the risk.

My route was new Criterion .308 barrel since hunting loads for the .308 are just as good as .30-06 for ranges and animals I want to harvest. When I bought the barrel I had it threaded at a machine shop 1/2x28 because there was not enough diameter to do the common 5/8x24 pitch. I have a YHM Phantom in .30 and YHM has quick detach mounts that are 1/2x28 pitch and rated for .30 cal. Their webpage has diagrams on what they expect the length of the threaded area to be because it is different than 1/2x28 rimfire and .223/5.56 ratings. I did have to cut off the gas cylinder lip to expose the barrel threads. I also have an adjustable gas plug on the end from Schuster. It is impossible to adjust it with the can on so be prepared to remove and re attach your can often while you dial it in. I don't care if it doesn't work when the can is off because I spent a lot of time and money to make it silenced and it's way cooler when it's quieter.

I also bought a spacer block to prevent loading .30-06 rounds in the magazine. It shouldn't chamber them, but rather be extra safe.

I kept the .30-06 korea era barrel, gas plug, and gas lock in case I ever return it back to as-purchased but I don't plan on doing that.

For OSS, I see them a lot on youtube channels and not sure if they're paying to get the name out or if they really are that wonderful. I already had my can and YHM is much better on mounting solutions than anyone else. They support "weird" pitches for European threads and they were the only ones that would easily share their spec for a QD 1/2x28 .30 cal mount and they sell it as a brake or flash hider. Everyone else's 1/2x28 QD mount was .22x diameter and that wasn't going to work for me. It looks like that OSS adapter is for .22 diameter to step up to fixed mount 5/8x24 and isn't going to let a .308 go through it.

I should subscribe to my thread because I missed all your posts. Sorry.

 

[Zellybob]

Thanks! Appreciate the thorough response. I had missed the adapter for .22 diameter... haven’t received it yet so i’ll have to see if it can be drilled out. The benefit i was thinking is the spacing it provides to still allow access to the gas plug for adjustments. Now you have me worried about the tolerance stack though... more thinking to do until i receive all the hardware.

 

[Zellybob]

Got it set up Friend with expert skills. Runout is less than .0005. Getting him some good whiskey!

 

[WalterSobchak]

Very cool project

 

[laf]

Cool project! Tanker style as well. Now where’s the video of it working??

 

[Zellybob]

Still waiting for the suppressor to be released... will be quite a few more months...

 

[Zellybob]

[video=youtube_share;dUPn9gG1rEw]https://youtu.be/dUPn9gG1rEw[/video]

 

[jwamplerusa]

[video=youtube_share;dUPn9gG1rEw]https://youtu.be/dUPn9gG1rEw[/video]

Is that an Ultimak upper handguard rail? I have one on mine. What is your LER scope?

Wonderful setup!

 

[Zellybob]

Thanks. Yea, ultimak with leupold fx-ii scout, 2.5x28

 

[laf]

Really quiet for being short! Super glad you finished it and it’s working. You get the gas system dialed in? Plans for it? Deer season is coming up

 

[Zellybob]

It’s super quiet, very happy with it. I didn’t have to adjust the gas plug at all, it’s an OSS suppressor, not much change to the back pressure. Not much of an hunter here, just plinking on the range

 

[Greffy]

The ejection angle is certainly different. Rearward for the standard and forward for the suppressed. That's what it looks like to me. Brass have any odd damage, or is otherwise normal?

 

[Zellybob]

This was the one time I didn’t pick up my brass, but noticed that too on the video. Next time going to play with the plug to see how much of a difference there is. Was too excited to shoot it the first session...