Thread: Suppressed 9mm

Originally Posted by Fssprecision

Yes a friend got a set a while back of various calibers, not got round to making one yet though, we could also do for 32 acp. as they run ok in old 303 barrels off cuts

I was thinking a 9mm might be subsonic out of a 2-3” 9mm ‘Barrel’ inside a .410 barrel. Once the projectile cleared the rifled section of the barrel it wouldn’t get any extra speed while travelling down the overbore section of the barrel.

A welded in adapter could be an easy way to achieve what your working toward while a removable adapter could give the option of a suppressed rifle that can convert quickly to .410 shotgun. The removable probably wouldn’t be very accurate but that wouldn’t be the end of the world as you wouldn’t be stuck with it.

The other adapter I always thought could be worthwhile is a .410 to 22 Hornet. Plenty of .224 barrel off cuts to get the raw materials for that one.


I do remember seeing an article in an old black and white shooters bible about a .303-.32ACP cartridge converter. They were trying to sell the idea as the poor man’s DeLisle carbine.


At any rate this is a neat option that your putting together, great idea for pig hunting.

Originally Posted by hotbarrels

My experience using a suppressed Marlin Camp before the great confiscation was that subsonic 9mm fails to expand the projectiles. Drilled pencil holes in goats and they kept running. Finding a good projectile and hand loading will be key to making it an effective hunting gun.

Personal experience of shooting goats with 158gn 38sp bullets from 20" Rossi at around 1200fps is that truncated cone or flat points do the job into engine room, neck or shoulder. The flat edge creates a much better wound channel than anything round. I have not gone subsonic tho,

Originally Posted by 300CALMAN

A bolt action in 9mm would be a great project. Considering the low pressures i guess a tube gun would hold up?

A 9mm bolt gun might be a cool rifle

But there is simply no comparison between the 9mm and 45 ACP
I have done 12 gauge chamber converters for both
9mm is a sweet little round but from my experience pretty unsuitable for hunting anything
The 45 ACP though is a large step up in diameter and power and does become a realistic hunting option of care is taken and it is used within its obvious limitations

Originally Posted by akaroa1

A 9mm bolt gun might be a cool rifle

But there is simply no comparison between the 9mm and 45 ACP
I have done 12 gauge chamber converters for both
9mm is a sweet little round but from my experience pretty unsuitable for hunting anything
The 45 ACP though is a large step up in diameter and power and does become a realistic hunting option of care is taken and it is used within its obvious limitations

My idea for 9mm was just a plinking gun. Yes especially if you want subsonic there's nothing like a 45.

Originally Posted by Cordite

Yes, works well. Have a footlong 12G adapter made from a .303 barrel but after making I got stung $50 for a box of fifty .32 ACP, no doubt flying fast out of the footlong barrel instead of some short-barrel pocket aberration.

The next one I might chamber in 9mm with a gradual throat reamed in, to squeeze 9mm lead bullets down to .303 and thus have better BC bullets emerge at slightly higher velocity (anyone remember the Myra Extruder?). Lead ball 9mm is much cheaper than .32ACP.

but you COULD use lead buckshot in your .32APC could you not???

Originally Posted by Micky Duck

but you COULD use lead buckshot in your .32APC could you not???

Haha. I have several hundred Lyman .32 90gn semi-wadcutters for when my hitler-suicide .32 FMJ cartridges are all spent.

My only burning question is ... will a single shot 12G 3" SG hold up to a .303-to-12G adapter? I guess the "rim" of the steel adapter would not hold and the adapter would get forced into the forcing cone.

Im meaning load your .32apc wit ha single buckshot ball instead of its usual projectile so it will be very similar so no difference to adaptor.
my single .12ga of older Spanish manufacture seems to be holding up to mid level .45/70 pressures well.
my way of looking at is was the pressure of cartridge fireing will be going in all directions and the force going rearwards is pushing a flat rimmed cartridge against a flat face of the shotgun...all the rest is inside the steel adaptor tube or dissapearing up the barrel...IF disaster struck and you got a SHTF moment,the gases would be going out sideways and down into action of shotgun,your face is behind that line...having experience one blowup,its NOT something I ever want to do again,so are cautious.

but if you meaning the rim holds adaptor back against face...Vs adaptor snug against forcing cone...well against forcing cone would be ideal....shouldnt be too hard to lightly shim it to do so with insulation tape if its loose...mine is so snug of fit,if anything heavier than light oil is applied to outside of sleave it wont slide inside SG barrel.

Originally Posted by longshot

I do remember seeing an article in an old black and white shooters bible about a .303-.32ACP cartridge converter. They were trying to sell the idea as the poor man’s DeLisle carbine.


At any rate this is a neat option that your putting together, great idea for pig hunting.

It was a flawed idea and never took off. .32ACP is same price as surplus .303, so not for the "poor" man. Also, .32 ACP (even better the hotter 7.65 Browning CIP/European loads) are very supersonic out of a full length rifle barrel.

Originally Posted by Cordite

Yes, works well. Have a footlong 12G adapter made from a .303 barrel but after making I got stung $50 for a box of fifty .32 ACP, no doubt flying fast out of the footlong barrel instead of some short-barrel pocket aberration.

The next one I might chamber in 9mm with a gradual throat reamed in, to squeeze 9mm lead bullets down to .303 and thus have better BC bullets emerge at slightly higher velocity (anyone remember the Myra Extruder?). Lead ball 9mm is much cheaper than .32ACP.

I just remembered I made this a few years back, a bit of old 303 barrel that acted as a liner in a shotgun, on top of that I built the suppressor, extractor and chambered it for 32 ACP. A guy wanted it for dispatching sheep and said he could get to within 20 yards or so but wanted it super quiet.

I ended up quite incredible and was just about silent and even though a rough old bit of barrel the bloody thing was hitting fence posts at 70 yards

now that is a thing of beauty!!!!!!!
would .32/20 work with same old 303 barrel perchance???

Originally Posted by Micky Duck

now that is a thing of beauty!!!!!!!
would .32/20 work with same old 303 barrel perchance???

To be honest I've no idea, with stuff like this you just have to try it to find out......would need a bit of research on comparable velocities and diameters to give some idea but like with the above it was a tired old bit of 303 barrel (maybe 5/10) and it just worked.

Originally Posted by Micky Duck

now that is a thing of beauty!!!!!!!
would .32/20 work with same old 303 barrel perchance???

The .32 S&W long is gruntier than .32 ACP, and cheaper.

Originally Posted by Fssprecision

To be honest I've no idea, with stuff like this you just have to try it to find out......would need a bit of research on comparable velocities and diameters to give some idea but like with the above it was a tired old bit of 303 barrel (maybe 5/10) and it just worked.

Nice work!!!

The .32 ACP bullet is 7.94mm, so expectedly good for worn .303 barrels as .303 bullets are 7.9mm.

How now did you attach the rail for the red dot? I suppose if you welded in the adapter then no worries about weakening the surrounding SG barrel chamber, or is it safe to drill and tap a couple of threads atop the chamber?

Originally Posted by Cordite

The .32 S&W long is gruntier than .32 ACP, and cheaper.



Nice work!!!

The .32 ACP bullet is 7.94mm, so expectedly good for worn .303 barrels as .303 bullets are 7.9mm.

How now did you attach the rail for the red dot? I suppose if you welded in the adapter then no worries about weakening the surrounding SG barrel chamber, or is it safe to drill and tap a couple of threads atop the chamber?

I made up a short rail and screwed it to the shotgun barrel, quite safe, don't forget that the 32 acp section was a liner that slid in. Really quite safe in most applications as long as you use short screws and don't drill through into the chamber, I also always use a smear of epoxy un the underside when mounting a rail.

Holy hecka- thats a lotta talent mate!