Thread: Eccentric over barrel rifle suppressors - anyone know?

To take a quote from a silencer forum I briefly became a member on "baffles are good".

Originally Posted by gundoc

I have made a few eccentric screw-on suppressors. They are a pain in the arse to make in comparison with concentric units, and the only major advantage they offer is the ability to use iron sights. They do give a slightly better suppression performance because of the inconsistent gas flow. The best eccentric design I have made in terms of performance and suppression is of rectangular cross-section, giving a greater internal volume than a cylindrical unit of similar dimensions.

If I had a lathe etc I would definitely give one a go. Another advantage is keep weight low and I guess potentially have unlimited volume without blocking line of sight.

Got a ~75cm lenght of galvanised 1 3/4" galvanised steel tube I found in my garden after former neighbour's trampoline blew across and dented my garage. Good place to start. Might do a really long counterbore on the SMLE and vent holes along the sides of the counterbore (think Madsen rifle). If she shoots OK I'll proceed further.

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This is the forum that I joined. 7 posts and haven't done one since I joined 3 1/2 years ago lol
from the land where you have to get a federal permit for a silencer the same as a rifle. It is issued to that silencer. Definitely not allowed to make your own willy nilly

Originally Posted by csmiffy

SilencerTalk - Index page
This is the forum that I joined. 7 posts and haven't done one since I joined 3 1/2 years ago lol
from the land where you have to get a federal permit for a silencer the same as a rifle. It is issued to that silencer. Definitely not allowed to make your own willy nilly

Yes, strange how the US is so awash with laws, including against silencers. Less "land of the free"; more home of the deaf. A moronic law.

I don't know what the actual stats are, how many murders get committed with suppressed guns vs with sharp/blunt objects, but I guess it does not matter. After all, it's plain from movies that killers for hire always use silenced guns...

I have one on my 357mag lever gun. Not sure who made it as it came with the gun and has no markings on it. Its a fairly sophisticated piece of kit.

Originally Posted by hotbarrels

I have one on my 357mag lever gun. Not sure who made it as it came with the gun and has no markings on it. Its a fairly sophisticated piece of kit.

Attachment 99987

Nice stainless can. Someone who is not a novice set it up in a 4-jaw chuck and did some eccentric turning.

Sounds like a familiar design.... mine was 405mm long and 2" dia, it is pretty heavy though, if I get my mits on another barrel I might try for some slots near the muzzle end, or maybe just fluted with ports at the bottom of the flutes. The only tricky bit with your idea is getting the crown sorted depending on how deep you counter bore it, maybe a brass rod that is a good fit for your hole with the end turned/filed/ground to the same angle as the drill bit and some valve grinding paste. Im not really convinced the baffles in mine do anything but I have a lot of relatively small ports

Originally Posted by Chilli_Dog

Sounds like a familiar design.... mine was 405mm long and 2" dia, it is pretty heavy though, if I get my mits on another barrel I might try for some slots near the muzzle end, or maybe just fluted with ports at the bottom of the flutes. The only tricky bit with your idea is getting the crown sorted depending on how deep you counter bore it, maybe a brass rod that is a good fit for your hole with the end turned/filed/ground to the same angle as the drill bit and some valve grinding paste. Im not really convinced the baffles in mine do anything but I have a lot of relatively small ports

Yes, prob with long counterbore is keeping it concentric with the bore, or the crown will not be at 90 degrees to the bore either. I think main thing is to counterbore to somewhere where there is good rifling (that is why this rifle is getting chopped), less important to have a beautiful looking crown. Some dude out there did experiments with simply hacksawing a new hunting rifle one inch at a time and shooting the rough end with only obvious burrs removed, no effect detected on accuracy. Anyway, if you use a drill with more of an angle on the cutting edges it's self centering.

I have an alternative idea taken from overbarrel silencers, where a barrel protector sleeve is often added. You can extend that sleeve forward of the muzzle right to/through the front of the silencer and perforate it to your heart's content. A small barrel counterbore of 2 inches can still be done, with side venting ports, and the sleeve can be perforated over those ports. Baffles can be welded to the sleeve if desired.

Both solutions seek to address @gundoc's stated/hated no. 1 problem with eccentric suppressors - alignment.

Originally Posted by Cordite

Yes, prob with long counterbore is keeping it concentric with the bore, or the crown will not be at 90 degrees to the bore either. I think main thing is to counterbore to somewhere where there is good rifling (that is why this rifle is getting chopped), less important to have a beautiful looking crown. Some dude out there did experiments with simply hacksawing a new hunting rifle one inch at a time and shooting the rough end with only obvious burrs removed, no effect detected on accuracy. Anyway, if you use a drill with more of an angle on the cutting edges it's self centering.

I have an alternative idea taken from overbarrel silencers, where a barrel protector sleeve is often added. You can extend that sleeve forward of the muzzle right to/through the front of the silencer and perforate it to your heart's content. A small barrel counterbore of 2 inches can still be done, with side venting ports, and the sleeve can be perforated over those ports. Baffles can be welded to the sleeve if desired.

Both solutions seek to address @gundoc's stated/hated no. 1 problem with eccentric suppressors - alignment.

Attachment 100111

Mine drilled pretty straight with a plain old jobber drill, its probably easier to build than the drawing above

Originally Posted by Chilli_Dog

Mine drilled pretty straight with a plain old jobber drill, its probably easier to build than the drawing above

Thanks, just revisited your .410 de lisle thread and saw your long 10mm drill construction.

Yes, think you're right about avoiding the complication of the barrel sleeve. If I index the front and back caps to the outer sleeve I may be able to hold it all together simply with a thread at the end of the barrel. Some de Lisles have a short bit of barrel sticking out front of the silencer and that could be the treaded bit holding a screw-on retaining cap. Sleeve and baffles can be added at will later but the design will work to a degree without such.