Shotgun chamber adapter 12ga to 357

M

mikerjf

Member
Joined
Sep 19, 2018
Messages
2,171
Reaction score
3,505
Had my first try with a $20 adapter off ebay. Adapts any breakopen 12ga to shoot 357 ammo.

This is a minimal length unrifled adapter. Essentially it is a 2-3/4" 12 gauge shell made from solid stainless steel, with a 357 chamber and short unrifled barrel stub machined into it.

Due to range rules I was forced to try this at 25 yards on a full-size sillhouette target. With a 20" shotgun having no sights (not even a bead) I was dubious. But I broke out a box of 38 Special range loads and had at it.

Result: Every single shot was on the "guy". Most would have been serious.

Kind of amazing with no sights and what amounts to a <1" unrifled barrel. Shows what I know.
 
Register to hide this ad
I would advise caution. I had an adapter to fire .30 Carbine in a .30-30 chamber. The adapter split longitudinally on the 2nd round. My last experience with an adapter. Not trying to rain on anyone's parade.

Kaaskop49
Shield #5103
 
I have quite a few adaptors. They are intriguing to me. I regularly carry either a 30-06, 308 or 30-30 and I have adaptors for each the 32 ACP. I will occasionally shoot a grouse or rabbit while toting one of the above. I have many adaptors of different calibers. In the above rifles, when sighted at 100 yards, 3" high with high power hunting loads, the adaptors usually print 1" low and 1" to the right when shooting at 25 yards with factory ammo. Plenty good enough for rabbit or sitting duck. I cronographed a few 32 loads in the longer tubes and got up to 1200 fps. Some of the other caliber adaptors are useless. The old Marbles adaptor from 250 Savage to 25ACP is hopeless even at 15 yards. Though I have 45-70 x 45 ACP and a 35 Remington x 380 ACP I have not tried them for accurate or point of aim. The shotgun adaptors are another story. I have quite a few unrifled in different gauges and different caliber. Everyone is only capable of pie pan accuracy at 25 yards and about have the bullets are keyholing at that distance. I do have a rifled 12 gauge x 22 LR that gives respectable 25 yard accuracy and point of aim. The new rifled adapters are too long to work on anything but break actions. I bought a rifled 12 x 9mm that I am going to shorten so it can be used in a conventional gun. Interestingly I have several adaptors from one gauge to a smaller gauge and getting good 25 yard patterns.
 
Just to note that you can get, for example, an 18" long adapter that is fully rifled.
 
Last edited:
Have a couple .32acp in a .30-06 inserts, never shot game with them but I’m sure they would be effective. Would be good to carry deer hunting to dispatch a wounded animal quietly if you don’t want to spook anything.
 
I have a polish flare gun I bought years ago along with adapters for my bass boat. One adapter was for .45 Colt/.410 rounds, one adapter for 12 gauge flares only and one adapter for .22 rim fire. It is an inexpensive operation as an emergency or survival gun. The .45 Colt rounds tumble at about 20 yards.
 

Attachments

  • 100_2604.jpg
    100_2604.jpg
    127.2 KB · Views: 37
  • 100_2605.jpg
    100_2605.jpg
    148 KB · Views: 28
  • 100_2606.jpg
    100_2606.jpg
    101.8 KB · Views: 28
Do you have to manually punch the spent shell casing out?

A novel idea I guess, but nothing I would try. Especially, if I had no idea of the grade of stainless being used. There is a plethora of grades.

I once had a pair of Shimano " stainless" fishing pliers I kept in in the back of my truck that had a Leer cap. Just the exposure to the atmosphere in the back of the truck rusted them to the point of being unusable.:eek:

I would be cautious
 
Here's an adapter I made for 45/70 Trapdoor to .22 LR. I couldn't make the barrel stub any longer or it wouldn't slide into the chamber.


I haven't tried it for accuracy (probably none.) yet but it goes bang just fine.
 

Attachments

  • Adaptorfinall.jpg
    Adaptorfinall.jpg
    236 KB · Views: 43
  • Adaptorcol.jpg
    Adaptorcol.jpg
    104.4 KB · Views: 31
I have some 12 to 20 gauge 'Lil Skeeter" adapters that work amazingly well..but have never tried anything else. I didn't even realize they made shotgun to rifle/pistol cartridge conversions.

I'm surprised you were able to keep any bullets on target, given the circumstances.
 
Breakaway500 said:
I have some 12 to 20 gauge 'Lil Skeeter" adapters that work amazingly well..but have never tried anything else. I didn't even realize they made shotgun to rifle/pistol cartridge conversions.

I'm surprised you were able to keep any bullets on target, given the circumstances.
Click to expand...

These adaptors are a re-invention of a old product. Back in the days when a woodman carried a gun all day, everywhere. They generally carried just a lightweight carbine. With it they carried, all their needs, usually in a pack. With these little adapters allowed for the carrying of large quantities of small game ammo for every day meals, while enough firepower in the rifle cartridges for protection and big game hunts. Many woods wanderers carried them. Ammunition manufacturers used to make full sized ammo with lightweight bullets and minimal powder for small game hunting. These were listed a "minatures".
 
You have to watch out for some of the available chamber inserts for shotguns to rifle/handgun calibers .
They seem to be made from nothing more than CRSteel or low grade stainless.
They can be OK with low pressure small dia rounds most times. But with many handgun rounds running in the 35K and over range in pressures, they need a quality steel and a good chamber cut just as much as any firearm.
I've seen a few of them split when fired.

The usually large dia and sloppy firing pin fit on most break open shotguns isn't a good thing for those high pressure rounds either.
Pierce a primer on one of those rounds in the breakopens and a lot of damage can happen to both the gun and the shooter.
That's why the firing pin is usually 'bushed' in conversions of the shotguns to CF calibers along with a gas seal system to at least protect the shooter.

Keep those glasses on..
 
Interesting. Would someone please post or PM links on shotshell to CF rifle adapters. I think I'd like a SxS in 500 S&W if can be safely done but also needs to be somewhat accurate, which may be asking for too much.
 
lamarw said:
I have a polish flare gun I bought years ago along with adapters for my bass boat. One adapter was for .45 Colt/.410 rounds, one adapter for 12 gauge flares only and one adapter for .22 rim fire. It is an inexpensive operation as an emergency or survival gun. The .45 Colt rounds tumble at about 20 yards.
Click to expand...

I have one of those plastic 12 gauge flare guns. It makes noise with 12 gauge shells emptied of their pellets. I've thought about loading the emptied shells with hot pepper flakes or something similar and using it on dogs when I'm on my bike.
I used to live in a county where people did not restrain their dogs. I've since moved away. A couple months ago a delivery driver was attacked over there and lost one or both of his hands to some mutts.
 
30-30remchester said:
Ammunition manufacturers used to make full sized ammo with lightweight bullets and minimal powder for small game hunting. These were listed a "minatures".
Click to expand...

Indeed they did. Back in the earlier days of the 20th Century, the ammunition companies loaded many of the more common rifle calibers (such as .30-30) as light lead bullet loads intended for shooting small game at close range and for finishing-off shots on wounded larger game, so as to not destroy much meat. The idea was for a hunter to carry a few of those rounds in his pocket in case they were needed. Somewhere I have a few of those rounds in .303 Savage. The Marble cartridge adapters allowed using low-powered handgun ammunition in CF rifles, e.g., using .32 ACP cartridges in .30 caliber rifles. I remember seeing some of those back when I was a kid, but haven't seen any for a long time.

The only adapter I ever had was a short one (not much longer than a fired shotshell) which allowed using .410 shells in a 20 gauge shotgun. I never had much use for it, but it did work OK the few times I fired it. I had to pry out (or punch out) the fired .410 casing. I thought it would be nice to have a longer rifled-barrel adapter, maybe 10"-15" long, in a rimmed caliber such as .30-30 for use in one barrel of a 12 gauge O/U or SxS double shotgun.

The idea is far from new, as even today, many skeet shooters using O/U shotguns have full length gauge reducing tubes so that their 12 gauge shotgun can also be used in 20 gauge, 28 gauge, and .410 events. But those tubes are pricey and usually have to be custom designed and fitted to the gun.
 
Last edited:
I remember old timers that had a few miniatures or gallery loads in their pockets for grouse and finishing off. There were quite a few larger rounds that were factory loaded with shot for small game. For years my 30 caliber hunting rifles had homemade miniatures loaded with 110 grain round nose FMJ's designed for the 30 carbine. A small amount of Unique lit it off.
 
I love guns and they are my hobby. I cut corners but when it comes to my hobby, I don't. I got a Lothar Walther 12 gauge conversion to .38 Special. It has a rifled insert and is minute of beer coaster at 25 yards.
 
mikerjf said:
Had my first try with a $20 adapter off ebay. Adapts any breakopen 12ga to shoot 357 ammo.

This is a minimal length unrifled adapter. Essentially it is a 2-3/4" 12 gauge shell made from solid stainless steel, with a 357 chamber and short unrifled barrel stub machined into it.

Due to range rules I was forced to try this at 25 yards on a full-size sillhouette target. With a 20" shotgun having no sights (not even a bead) I was dubious. But I broke out a box of 38 Special range loads and had at it.

Result: Every single shot was on the "guy". Most would have been serious.

Kind of amazing with no sights and what amounts to a <1" unrifled barrel. Shows what I know.
Click to expand...

I have such an adapter that is dated 1901. It is chambered in .32-20. Will see if I can find the pictures of it and post them.
 
You must log in or register to reply here.

Similar threads

H
LC Smith 12ga shotgun DOB info
Replies
5
Views
451
2152hq
2
M
Picked Up A Project Shotgun
Replies
10
Views
803
merl67
M
Narragansett
Mossberg 12ga skeet gun
Replies
3
Views
413
kscharlie
kscharlie
R
$89 New Shotgun
2
Replies
38
Views
2K
THE PILGRIM
THE PILGRIM
Y
Shotgun ‘Smith for trigger jobs?
Replies
10
Views
696
BARgunner
B

Latest posts

Back
Top