[NFA] Suppressing an M1 Garand?

[heypete]

Something odd occurred to me while I was cleaning my M1 Garand this evening: the threads on the barrel that are used, in combination with a little screw-on bit and the gas plug, to hold the front sight assembly on the rifle would be ideal for mounting a suppressor.

Obviously, it'd need to be fit properly and with enough room for the gas plug to screw in, but I figure it'd be possible.

Now, a suppressor would probably muck with the pressure curve and might stress the op-rod, but I wonder if that could somehow be compensated for?

Anyone know if such a suppressor exists? I know there are many .30 caliber suppressors on the market, but most of them are for bolt-action guns, not semi-autos, and I've certainly not seen any for the M1.

 

[PercyShelley]

http://www.surefire.com/maxexp/main/co_disp/displ/pgrfnbr/517/sesent/00

Surefire has a number of sound suppressors intended for semi auto weapons in the 7.62mm range.

 

[Ian]

I talked to and emailed a couple suppressor companies about this very question not too long ago, and they basically all said it would have to be a one-off custom deal (not enough market). You'd have to first get a custom-made barrel extension of some kind; the threading for the gas plug isn't long enough or of the right size for a standard suppressor.

 

[mpmarty]

Then you have to figure out how to get an ancient battle rifle to operate at all with a sub sonic cartridge. Ya see ya can't suppress a cartridge with over a thousand feet per second velocity the "crack" a rifle makes is the bullet breaking the sound barrier as it exits the muzzle.

 

[Zak Smith]

Ya see ya can't suppress a cartridge with over a thousand feet per second velocity the "crack" a rifle makes is the bullet breaking the sound barrier as it exits the muzzle.

However, the "crack" is not the loudest part of the report. There is a dramatic difference in shooting a suppressed vs. unsuppressed centerfire rifle with full-power ammunition.

 

[heypete]

Ian: I figured there'd be some custom work involved, and I know a few local manufacturers that can build such silencers, but I just wonder about the gas pressure involved -- the M1 is particularly sensitive to the pressure curve (needing to be very close to M2 Ball spec, else it bends the op rod) and I know that silencers would change that pressure curve a bit.

mpmarty: Not entirely true. I've fired suppressed M16s (yes, full-auto ones) and while the crack from the supersonic shots is still present, the muzzle blast (usually quite a bit louder) was greatly reduced.

This is evident when shooting .22LR ammo suppressed, and you can see the difference between super- and subsonic ammo both suppressed and unsuppressed here.

As Zak points out, there's a significant difference in the noise generated between suppressed and unsuppressed rifles shooting supersonic ammunition. Obviously, the shot is far quieter with subsonic ammunition, but it's still reduced quite a bit even with supersonic stuff.

 

[Correia]

Ya see ya can't suppress a cartridge with over a thousand feet per second velocity the "crack" a rifle makes is the bullet breaking the sound barrier as it exits the muzzle.

I fired over 1,000 rounds of suppressed 5.56 last weekend. The supersonic "crack" is really more of a mild chuff, and even on my 10.5" gun it sounds like an unsuppressed .22LR.

 

[Ian]

Hmm...I have no idea how much impact a suppressor would have on the pressure curve. However, I'm not sure the Garand is quite so fragile as you make it sound. A slightly lower pressure/velocity loading would solve any potential problem, I would guess.

If you find out any more info on how to do this, please post it - I'd be really tempted to get a suppressor for my M1 if I could.

 

[Bartholomew Roberts]

The other nice thing about a suppressed full-power rifle cartridge is the "crack" of the bullet travels with the bullet, unlike the initial muzzle blast. I love shooting my suppressor on bays where you can here the crack reflect back off all sides of the berm as it travels downrange.

 

[loadedround]

FYI, Brownells sells a muzzle brake/suppressor for the M1 Garand that is a no 'smith drop in.

 

[Ian]

That brake is made by Smith Enterprises, who specifically states that's it's not for use with their .30-cal suppressors. I don't know why, though - could be that it doesn't have a tight enough straightness spec (something that would be necessary for a long suppressor but not for a simple muzzle brake), or just because the QD system isn't compatible with it.