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M1 Carbine converted to 5.7MMJ 200 meter range report

Posted: Sun Jan 13, 2019 2:44 pm
by Rapidrob
5.7 MMJ Johnson Spitfire M1 Carbine conversion from the 1960’s

A few decades ago I acquired a M1 Carbine that had been converted to 5.7 MMJ or the .22 Johnson Spitfire cartridge.
This is the .30 Carbine case necked down to .223 with a shoulder common to our .222 Remington.
Without going into the long history of Melvin Johnson’s conversion and manufacture of these carbines, I’m just going to write about mine.
This is the 2ND converted carbine I have owned, however this little guy was a very early conversion of a once beautiful Winchester M1 Carbine. Remember that carbines were 20 bucks from the DCM. They had millions to get rid of.
Mine was what we would call today a “Bubba” job, be it though very well done but not thought out fully.
The stock had the oilier slot filled in with wood, a recoil pad was installed to increase the length of the pull and then a Weaver scope was mounted.
This was the carbines Swan Song. The receiver had the rear sight milled off and the receiver was drilled for a very low mounted set of rings. So low in fact that the fired casing would not eject 95% of the time when fired.
Regrinding the face of the ejector did not help this problem.
The carbine was very accurate at 300 yards, in fact it was so good I hated to not shoot the thing but it was just too hard on brass and a pain to clear the jammed action and crushed brass.
Jump to the last week of 2018. A local gun show had a guy with tons of carbine parts.
I found a brand new Springfield Armory receiver for a very fair price. Quality is first rate.
So began the journey to bring the safe-queen out to be shoot at our range.
I bought a receiver and barrel wrench and proceeded to disassemble the carbine down to its component parts. All are Winchester marked.
I mounted the 5.7 barrel into the new receiver and timed and head spaced it as needed.
I then found a well used Korean stock set of wood that had returned to the states.
The barrel was not milled for a front sight and I had to do that. I also installed a milled rear sight and zeroed it.
The completed carbine at least looks OK now and was serviceable.
I made up a hundred cases which is very easy to do if you don’t rush the resizing of the neck and shoulder.
This barrel has the correct rifling twist of 1:14”. Some of the later barrels are much tighter and you can get into trouble using the maximum load data with too high of pressures and blown primers or case heads.
Col. Johnson loved the 40-45 grain bullets used in the .22 Hornet and .218 BEE loads and that is what I use.
You can go heavier but accuracy and pressures are affected that are hard on the carbine’s action.
I use IMR-4227. I have tried other powders such as 2400 and flake powder from overseas with poor results at 200 plus yards.
Using 14.0 grains of IMR-4227 and a nice round nose or semi-spitzer tipped bullet really is the way to go. You cannot seat a polymer tipped bullet deep enough to fit the magazine and be able to crimp the bullet properly.
My carbine will feed any of the .22 Hornet or .218 BEE bullets with any type of tip with no problems.
Ejection is swift and sure. The fired cases are two feet away in front of the firing point.
I took the carbine to the range yesterday. It was cold but calm.
We placed our reduced size man torso AR500 steel target at 200 meters and I fired from the prone.
The little bullet strikes 1 foot high at this distance. Being so fast and light I expected this.
Using a six o’clock hold placed the rounds just above dead center if I did my part.
The target was hung on a chain and this allowed the target to turn sideways after a couple of shots, which it did. This became a real challenge to hit but the carbine did hit it many times.
I fired 100 rounds of ammo using five different types of bullets. All shot to the point of aim only having to adjust for windage to compensate for spin drift.
On of my club’s members provided me with a full can of Arizona Iced Tea to use as a target. I set it on the rail at 50 meters and fired at it. When the bullet struck, the full can of tea exploded as if an M-80 had been dropped into it. The remains were blow 20 yards from where it had sat. One piece was never found. The members who witnessed the shot were duly impressed with the striking force of the 40 grain bullet moving at 3,000 FPS.
Recoil is very mild, a little less than shooting an AR-15 with M198 Ball ammunition.
Report is much less than expected. If you were hunting with this little carbine your ears would not be ringing when you fired it.
Here are a few of the targets shot using the 5.7 MMJ carbine at 200 meters. The second man torso group was using the same bullet and me trying to hold the sights on target the best I could. Of course the target spun making it much harder to hit. (Notice the raindrop shaped hits from the steep angle of impact.
Melvin Johnson’s full automatic mini-version of the M1 carbine is reported to have gone to South America. With its NFA short barrel and folding wire stock would have been ideal for jungle fighting. I can only imagine how well it must have worked.
With my newly revamped toy I’m really happy with it at the range.
I have to try it at 500 meters just for giggles to see what it can do.
Here is what it used to look like
carbine5.jpg (263.82 KiB) Viewed 2705 times
Here it is now
carbine1.JPG (42.97 KiB) Viewed 2705 times
this was the first target using 5 diff bullet types
target1.jpg (89.44 KiB) Viewed 2705 times
2ND target with one type bullet and really trying to shoot a group
target2.jpg (171.86 KiB) Viewed 2705 times
Target turned even farther and I got a hit on the edge of the target
target3.jpg (116.57 KiB) Viewed 2705 times
Here's whats left of the can of iced tea at 50 yards
iced tea can.JPG
iced tea can.JPG (132.48 KiB) Viewed 2705 times

Re: M1 Carbine converted to 5.7MMJ 200 meter range report

Posted: Sun Jan 13, 2019 5:06 pm
by ammolab
that little rifle looks “right” now. ...good work. Now engineer some brace for the target hook or pole to keep that little target square.

Re: M1 Carbine converted to 5.7MMJ 200 meter range report

Posted: Mon Jan 14, 2019 5:20 am
by vandle
ammolab wrote:
Sun Jan 13, 2019 5:06 pm
that little rifle looks “right” now. ...good work.
I tend to agree.

Re: M1 Carbine converted to 5.7MMJ 200 meter range report

Posted: Mon Jan 14, 2019 7:13 pm
by m47dragon
Very cool! Way to resurrect a classic👍