Print Page | Close Window

10mm Magnum M1 Carbine (Video)

Printed From: The Carbine Collector's Club
Category: The Club
Forum Name: General Discussion
Forum Description: Carbine Related
Printed Date: Mar 01 2024 at 5:09am
Software Version: Web Wiz Forums 12.01 -

Topic: 10mm Magnum M1 Carbine (Video)
Posted By: TonyRumore
Subject: 10mm Magnum M1 Carbine (Video)
Date Posted: Sep 18 2023 at 2:27pm
This was assembled back in 2003 on an old stripped surplus Iver Johnson receiver.

Tony" rel="nofollow -

Posted By: floydthecat
Date Posted: Sep 18 2023 at 3:19pm
Conversions are interesting and a fun project. They are much more practical when converted to a caliber that is more available and much cheaper than 30-carbine such as 9mm.

Posted By: W5USMC
Date Posted: Sep 18 2023 at 5:10pm
Tony, welcome to the forum. Always like reading about conversions especially when they run as they should. The 10mm Mag is pretty impressive. Thanks for posting.

USMC Retired
NRA Life Member

Posted By: New2brass
Date Posted: Sep 20 2023 at 8:45am
Tony, Nice job!
you said the piston is bigger and longer, or just longer?
Did you modify the weight of the slide or use stronger springs?

I am sure there are some that would like to see the trigger housing modification for the magazine.

IN the past year I have been helping with the Larry Ruth estate and handled many different conversions, I had little interest in most of the conversions and in hindsight I wish I would have paid a little more attention.
.30 carbine short
.256 Win Mag
.40 S&W
.45 Win Mag

There is a 10mm in the collection made by Walter Halfler that uses modified M1 carbine magazines.

Some interesting carbine conversions I did take note of.
Aberdeen Proving Ground Small Caliber High Velocity test gun in .244. this was what lead to the M16 cartridge. this uses slightly modified M1 carbine magazines.

Gordon Ingram Police prototype in .223, This is not a caliber change in the simple sense, It is a longer carbine receiver and takes the M16 magazine. Gordon Ingram is a noted gun designer and father of the MAC 10

There is also a conversion to a pump action. It is still .30 carbine
It is not like the Universal Vulcan, which was a caliber change. I guess this was to have a M1 carbine that was not semi auto.

Most of these can be seen in one of these threads" rel="nofollow -" rel="nofollow -" rel="nofollow -" rel="nofollow -

If anyone wants specific pictures let me know

-------------" rel="nofollow - Club Survey Saginaw Receivers

Posted By: floydthecat
Date Posted: Sep 20 2023 at 3:12pm
I won’t answer for Tony but since I have been involved with various 30-Carbine caliber conversions I can comment on what it takes to make one run. If one selects a caliber with a round that closely reproduces the original chamber pressure design, no modifications to the gas system may be required. In some cases one might encounter a situation where a particular caliber may even produce excessive chamber pressure. The caliber choice has to be compatible with the required chamber pressure or modification to the gas system might be required and must not exceed an OAL longer than the action can accept.

Posted By: floydthecat
Date Posted: Sep 20 2023 at 4:29pm
PS: Modification of the gas system can mean shaving the inside of the piston base to increase stroke, countersinking the piston nut deeper for the same reason, opening the gas port to allow more flow…or some combination of all three. In my experience, a type V or VI slide cannot be used due to the changes made in those later slides to retard bolt opening.

Posted By: TonyRumore
Date Posted: Sep 21 2023 at 10:19am
The piston is .513" diameter externally with a .630" stroke.  I'm not sure of the ID of the gas cylinder I made.  I also put one together in 502 Thunder Sabre, but I don't have any pics of that one.  It was on a Universal.


Posted By: floydthecat
Date Posted: Sep 21 2023 at 10:53am
I’ve managed to keep my conversions as close to GI spec as possible only having to modify the piston and nut using a spec re-bored barrel. Your work demonstrates thoughtful engineering and craftsmanship. Working out the magazine solution can be an issue and it seems you’ve handled that well also.

Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.01 -
Copyright ©2001-2018 Web Wiz Ltd. -