Suppressed Mini-G issues

[txarsoncop]

Actually mine's a Mini-(BM)G I guess? Has Shuff even come out with an official designation for the Minis with the BM59 drop-down cylinder?

Anyway, I bought one of the 'builder gas locks' from Standard Parts and had a LGS who claimed to be capable (and was recommended) thread it up for me. He also installed the muzzle adapter for the suppressor and told me I was 'good to go.' I took his word for it, took it home and test fired with out the can and could only get single-shot fire out of it no matter how I adjusted the Schuster. Got frustrated and screwed the can on and tried it and was finally able to get some semi-auto function but not reliably and TONS of gas in my face. After giving up and taking the can off I heard a light rattling. Turned out I'd had a minor baffle strike. Took the muzzle adapter off to reveal a thread job that looked worse than any plumbing pipe I've ever worked with. The gas lock was also visibly non-concentric. Quick call to Tim and check of the rifle verified that LGS screwed gas lock on two turns two far and occluded gas port.

Has anyone else used one of Standard Parts 'builder gas locks' and had any luck with a competent 'smith threading it?

Kinda wishing I'd stuck with the Mini-G config and could just order the threaded gas lock from Fulton Armory..

25062507

[timshufflin]

All I can comment on this is that you have to have the gas port aligned to make the rifle work and the threads have to be concentric to make a suppressor work. I'll also add that there is no way there's enough support on that muzzle for a suppressor. I have no idea what the guy did, as in the whole story, but just what I've seen here isn't good.

I have had customers suppress these. One had me make an extra long muzzle which he had someone thread for some type of screw on sleeve and nut tensioner. He reported good results as the Schuster vents off the gas that you had blow back in your face. Hard to vent anything though when the gas port isn't lined up.

[timshufflin]

I'll also add that, and I don't know suppressors, it would seem that they would have threaded the ENTIRE gas lock to get more support and have a nut on there to tighten it.

[txarsoncop]

Tim,

Appreciate your comments as always. The gas lock was threaded the necessary amount to seat the muzzle adapter's shoulder and could not be threaded completely. Was hoping somebody else had gone/tried this and might chime in with some advice or references.

Thanks for the tips in helping to get the gun running again. If I can get the gas lock issue figured out I'll get back with you on an extended muzzle.

[timshufflin]

Tim,

Appreciate your comments as always. The gas lock was threaded the necessary amount to seat the muzzle adapter's shoulder and could not be threaded completely. Was hoping somebody else had gone/tried this and might chime in with some advice or references.

Thanks for the tips in helping to get the gun running again. If I can get the gas lock issue figured out I'll get back with you on an extended muzzle.

It is my opinion to thread the entire thing and use a jamb nut. That’s the method I’ve seen that worked.

Edit, also did someone TIG or braze your gas cylinder?

[timshufflin]

I keep coming up with more stuff. Did they thread the muzzle of the barrel or Standard Parts gas lock?

[timshufflin]

What suppressor are you using?

[ordmm]

What suppressor are you using?

Would be interested in the thread spec....was this for an oil filter adapter?

[txarsoncop]

It is my opinion to thread the entire thing and use a jamb nut. That’s the method I’ve seen that worked.

Edit, also did someone TIG or braze your gas cylinder?

I get what you're saying about the jamb nut. And yes, the GC was TIGed closed on both sides since I wasn't planning on using grenade sights.

Only thing the local 'smith threaded was the outside of the gas lock. Gas lock threads on like normal.

Suppressor and muzzle adapter are both from Rugged, the can is the Surge 762 with ADAPT module. Pretty quiet, kinda long with the extra module added (doesn't have to be used), but I can also change the endcap when I shoot sub .30 caliber to 5.56 to keep things quieter.

[timshufflin]

Would be interested in the thread spec....was this for an oil filter adapter?

Like Greg said, what's the thread and pitch? It is my opinion that you need to have someone thread this who can take it in and do it in house. Preferably someone who makes cans. I'd let them know before hand if the amount of support you can make from the lock is enough to support the can.

[txarsoncop]

Would be interested in the thread spec....was this for an oil filter adapter?

5/8x24, fairly typical for .30 caliber and no.

[timshufflin]

Sounds like the barrel is going to have to be threaded or a larger diameter hole will have to be used on the suppressor.

[jbkf1003]

Is that a BM59 Gas cylinder that's been filled in?

[txarsoncop]

Sounds like the barrel is going to have to be threaded or a larger diameter hole will have to be used on the suppressor.

Assuming you're referring to an extended muzzle? Since barrel can't be threaded larger and longer would interfere with gas lock fit unless it was re-threaded for the entire ID.Only about 1/2 inner length came threaded OEM and am beginning to suspect these were non-concentric to be gin with but have yet to try threading it onto my other two Garand rifles to check. Also noted they have not been offered by Standard Parts since my post..

Larger ID suppressor would put my into 'Big Boy' category and into significant more money or a complete custom which would be the same thing. If that's my only option, I'll let her bark.

[txarsoncop]

Is that a BM59 Gas cylinder that's been filled in?

As mentioned in Post #9, yes. I had the grenade launcher cylinder TIGed closed because I have no intention of firing dummy grenades from my carbine.

[Punch The Clown]

I don't think the M1 gas system lends itself to using a suppressor. The dwell time is just way too long.

[ordmm]

Assuming you're referring to an extended muzzle? Since barrel can't be threaded larger and longer would interfere with gas lock fit unless it was re-threaded for the entire ID.Only about 1/2 inner length came threaded OEM and am beginning to suspect these were non-concentric to be gin with but have yet to try threading it onto my other two Garand rifles to check. Also noted they have not been offered by Standard Parts since my post..
:
Larger ID suppressor would put my into 'Big Boy' category and into significant more money or a complete custom which would be the same thing. If that's my only option, I'll let her bark.

How was the threading performed on your rifle? With a die or single pointed in a lathe?

EDIT to add comments----

A few things to take into account---

--I guess you could swap any one component, or all of them to other barrels. Unless ALL the barrels were exactly the same---threads exactly the same spec? O.D. of barrel to bore--are they exactly the same in regards to concentricity? And there would be more considerations I think, but, and it's just my opinion, swapping between barrels with specs that most probably differ would not mean much.

--Parts "stack up"-- Lots of thread interface combinations going on with your installation. But, if the gas lock was installed with the rifle barrel bore indicated between centers or a spider, or even a four jaw chuck, then most probably any run out from the gas lock would be removed when turned to size in preparation for threading while still setup between centers, or other means to ensure no change.

--The M1 rifle poses a lot of challenges in regards to hanging things on the front end. Even if everything was indicated, turned on centers and centerline of bore in relation to final threading was dead nutz on, then what about repeatability if all the parts are removed down to the gas cylinder and then re-installed? Most probably you would want to recheck the whole installation again. Maybe a range rod ground to fit the barrel bore and installed device might be a prudent thing to have.

---And why the part is not offered anymore.----Same as other items that are not posted for online availability. One observation is when problems are brought onto the internet for discussion instead of a phone call to vendor or source to discuss the issues first. In most cases many internet discussions jumps the shark and heads in multiple direction in multiple venues and becomes nothing more than a dumpster fire. Not saying that's the case here, but most often time it is.

So, the part in question was done to a print by a qualified shop well versed in firearm parts and C3 weapons. The print called out certain requirements as to thread spec, use of a certified thread gage, material and so forth.

Since we are about to the bottom of the bin on this component it's simply easier to drop it from inventory.

If you have any questions you can contact me thru this site, or via email thru our website.

Greg
StandardParts LLC

[timshufflin]

Shouldn't matter if the gas lock was concentric or not, those who lathe it/thread it should be making it concentric. Even if that lock was made concentric though, I don't see the necessary support. That lock would have to be threaded all the way back and even then, would the suppressor manufacturer say that was enough support? There's a lot of moving parts here.

I'll say it again though, the one guy who I saw a Mini-G successfully suppressed, used an extended muzzle and a jamb nut.