Sound Suppressor Can Jam

[Richard H Brown Jr]

Greetings:

Not usually a poster on the mouseguns channel.

Saying that, had a fun time at the National Park range yesterday. Shooting Classic US Mil guns. M-1 carbine. M1903 Springfield.

People in next lane over were shooting civilian m-4 style AR's. Un-screw the flash suppress.. err gas deflect.. whatever. and screwed on what looked to be a oil filter can style suppressor. Ran a mag thru and had another guy try it, and got a fail to fire, and the carrier group seemed to be jammed.

Butted in, and tried to see what was wrong. Charging Handle and bolt carrier group were stuck. Managed to get the rear take-down pin out and tilted the upper group up (keeping the barrel up and down range, in case of a hang fire). Got the Bolt carrier and charging handle out and then removed the front pin and got the upper off the lower receiver.

Bullet was chambered and for some reason the bolt face hadn't locked around the rim. Had to ask around the other shooters for a .223 cal. sized cleaning rod. Ran it down the barrel and the round popped out. No damage to brass and primer not dimpled.

Proceeded to put the rifle back and was about to suggest that they load a single round and see if the problem returned, when I had an idea. Pulled the bolt carrier group and charging handle and looked at the face of the bolt. Jammed solid with what looked like mulched paper or fibre, on the face of the bolt. Scraped it clean with fingernail and a busted jewelers screwdriver, and reassembled the rifle, and had them fire a single round, and then 2 to check for function. AFTER they removed the suppressor can, and put the gas deflector back on. Worked.

Evidently oil filter style suppressors that contain some sort of fibre for cleaning oil, aren't the best type of suppressor for AR platform rifles.

I'm guessing the fibre material was light and loose enough, that the action cycling pulled some out of the can back into the barrel. and either pulled enough back down the barrel to mat up on the bolt face, or more likely the gas circulation pulled some up thru the gas tube and then thru the bolt carrier key. Enough gas and fibre threads to cycle the bolt group back, but enough left over fibre to stick to the bolt face and build up enough to where the cartridge rim wouldn't mate with the bolt face and extractor.

The shooters did have a very wet (lubed) Bolt carrier group, and charging handle and that probably helped gum up the bolt face.

Final reassembly, had them chamber a single round thru the ejection port, and the weapon fired, they then locked a mag and fired 2 rounds to check ejection and feed. Worked. Did suggest that they see a good AR smith, as there may still be some fibre in the gas tube.

When I say oil can suppressor, I didn't look closely at the suppressor, or ask what brand. With just a quick look, it seemed to be a large aluminum can with just one hole on the top of the can threaded to mate with an AR barrel threading and locked with a lock washer. the other end was flat thin metal, and the passage of the bullet just punched a hole thru the end of the can.

Did a fast image search for oil can sound suppressors, and it looks to be more like the solvent can style suppressor.

They were happy that they could keep shooting, and I JUST had to add insult to injury by letting them each fire a single .30-06 round out of my 98-yr old Springfield M1903 mix-master. While making comments that it's official zero was around 247 or so yds. And would reach out past 2,700 yds using the M1905 iron sights. And no buffer springs and gas bleed off to lessen the recoil into the shoulder.

So if you play with sound suppressors, it might be a good idea to figure out a way to blast air down the gas tube once in a while to clean it out really good. And the bolt carrier key face that mates the end of the gas tube. Computer dry air can and the plastic tube might work.


Just a heads up on an unusual (to me at least) jam, fwiw.


RHB

[PhillipM]

There is no vacuum to allow atmospheric pressure to push oil filter material to the bolt face.

[joem]

There was a guy that sold adapters that allowed one to screw a oil filter can to a rifle or pistol. When the oil filter was worn out simply go to a auto parts store and but another oil filter. I guess the BATFE put him out of business.

[Tuna]

You can still buy them but they have to be registered like a normal suppressor. Last price I heard was around $80 for the adapter that you put the oil filter on. I have seen them on .22 LR pistols and they seem to work very well.

[dave]

I have seen them for sale at a lot of gun shows (adopters) and always wondered if people were using them illegally.

[noslack327]

I would guess the ones, oil filters I see at gun shows are illegal, I do know that with a mistic x on a ar, it gets filthy with carbon. and when I shoot a TR45 on a 45 auto it takes better than an hour to clean the pistol frame of carbon, cleanest seems to be a 300 blk bolt action suppressed.

[TomSudz]

I see "adapters" at every show I go to. They are sold as solvent traps for use when cleaning firearms. They are completely legal when used for the stated purpose. If used to mount an oil filter for the purpose of acting as a suppressor they are illegal- unless the owner goes through the process of registering the adapter. I've seen the adapters for oil filters and more recently fuel filters. A friend told me he has seen one designed for use with a maglite flashlight body.