Another way to empty 357 cases

jmorris · November 17, 2015, 06:04 PM

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 · November 17, 2015, 10:03 PM

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 · November 17, 2015, 10:10 PM

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

**JohnKSa** · November 17, 2015, 10:11 PM

Neat project!

How do you eject the fired case?

Radny97 · November 17, 2015, 10:18 PM

Wow that's some fun stuff!

Kosh75287 · November 17, 2015, 10:22 PM

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 · November 17, 2015, 10:31 PM

Those adaptors are already commercially available.

**JohnKSa** · November 17, 2015, 10:58 PM

Quote:

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 · November 18, 2015, 09:24 AM

Quote:

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 · November 18, 2015, 12:04 PM

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 · November 18, 2015, 02:34 PM

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 · November 18, 2015, 09:19 PM

Quote:

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.

November 17, 2015, 06:04 PM	#1
jmorris Senior Member Join Date: November 22, 2006 Posts: 3,077	Another way to empty 357 cases 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.

November 17, 2015, 10:03 PM	#2
j357 Senior Member Join Date: January 25, 2009 Location: Liberty Twp, OH Posts: 283	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. Last edited by j357; November 17, 2015 at 10:13 PM.

November 17, 2015, 10:10 PM	#3
FITASC Senior Member Join Date: December 6, 2014 Posts: 6,441	Neat, but are those threads on the muzzle end of the insert? And if so, why? __________________ "I believe that people have a right to decide their own destinies; people own themselves. I also believe that, in a democracy, government exists because (and only so long as) individual citizens give it a 'temporary license to exist'—in exchange for a promise that it will behave itself. In a democracy, you own the government—it doesn't own you."- Frank Zappa

November 17, 2015, 10:11 PM	#4
JohnKSa Staff Join Date: February 12, 2001 Location: DFW Area Posts: 24,972	Neat project! How do you eject the fired case? __________________ Do you know about the TEXAS State Rifle Association?

November 17, 2015, 10:22 PM	#6
Kosh75287 Senior Member Join Date: October 15, 2007 Posts: 820	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. __________________ GOD BLESS JEFF COOPER, whose instructions, consultations, and publications have probably saved more lives than can ever be reliably calculated. DVC, sir. انجلو. المسلحة. جاهزة. Carpe SCOTCH!

November 17, 2015, 10:18 PM	#5
Radny97 Senior Member Join Date: July 8, 2015 Posts: 1,021	Wow that's some fun stuff!

November 17, 2015, 10:31 PM	#7
hartcreek Junior member Join Date: April 22, 2014 Location: Washington Posts: 1,549	Those adaptors are already commercially available.

November 18, 2015, 12:04 PM	#10
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	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). __________________ My Anchor is holding fast! I've learned how to stand on my own two knees...

November 18, 2015, 02:34 PM	#11
Kosh75287 Senior Member Join Date: October 15, 2007 Posts: 820	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... __________________ GOD BLESS JEFF COOPER, whose instructions, consultations, and publications have probably saved more lives than can ever be reliably calculated. DVC, sir. انجلو. المسلحة. جاهزة. Carpe SCOTCH! Last edited by Kosh75287; November 18, 2015 at 03:00 PM.