Another way to empty 357 cases

[jmorris]

I had a 9" section of a 9mm barrel left over from another project I had sitting around for awhile and finally did something with it.

Turned it down to fit the 20ga chamber of one of my 24's. After a fellow tinkerer loaned me a reamer I shot some groups with it today and managed a 1.5" 5 shot group at 25 yards with it today, with some mild cast 158 gn loads.

 

[j357]

That is truly an interesting piece of work and great results IMO. How short is the turned barrel/insert you made as compared to the original m24?

Just for reference, I have a 24 in 22/410 and am curious about expanding use for small game via .38 Spl with a 158 LWC running a little slower than the .357 application.

 

[FITASC]

Neat, but are those threads on the muzzle end of the insert? And if so, why?

 

[JohnKSa]

Neat project!

How do you eject the fired case?

 

[Radny97]

Wow that's some fun stuff!

 

[Kosh75287]

I own a single-shot 12 ga. with a 30" full-choke barrel, that is just ASKING for something like that! That is entirely too cool!

1.5" @ 25 yards is nothing to take lightly! I know many old lever guns that won't do that well.

I'm wondering what you might get in terms of velocity from a 9" un-vented barrel, if you shot some factory loads through it. I guess it might be prudent to not use too hot a load through it, in deference to the shotgun's action, but it sounds like you have a handle on something with considerable potential.

 

[hartcreek]

Those adaptors are already commercially available.

 

[JohnKSa]

I'm wondering what you might get in terms of velocity from a 9" un-vented barrel, if you shot some factory loads through it.

Here's a website that should provide some insight.

http://www.ballisticsbytheinch.com/

Their test results suggest that going from a 4"bbl to a 9"bbl will usually net you about 100fps, maybe up to 200fps in some loadings.

 

[jmorris]

Neat, but are those threads on the muzzle end of the insert? And if so, why?

Yes, they are. The section of barrel was the drop from a suppressed 9mm AR upper build some years ago.

Just figured I would find some way to put it to use turning money into noise.

 

[mikld]

How do you keep the insert tight in the barrel? If it's sloppy fit it might move around affecting accuracy.

Good job, even if you can buy sub caliber inserts, home made is much better! (I think commercial inserts are much shorter by the way).

 

[Kosh75287]

JohnKSa, thank you for the information. I should have known to check there.

I'm finding a couple of sub-caliber insert manufacturers, but none of them make inserts in .357mag. Lotsa .38 Spl. inserts, though. One might expect it to be the other way around, since .38s can be fired in .357 Mag chambers. Curious...

 

[jmorris]

How do you keep the insert tight in the barrel? If it's sloppy fit it might move around affecting accuracy.

It locks up when you close the action and the insert is machined to fit that particular barrel (yeah, that took some time).

I thought about machining o-ring groves to see if I could get more accuracy out of it but then I would also need to machine an ejector that would work in conjunction with the 20 ga unit vs just tipping the barrel up and maybe removing the insert and hand on the muzzle "flicking" the case at my feet.

Not sure I am that interested in it, was just playing around.