I was thinking about trying to make a 22LR center fire out of a 25 ACP cartridge. I wonder if it has ever been done before.

It would take modifying the firing pin to center fire but that would be the only gun mod necessary. The cartridge would have to have the rim cut to .278" and extractor recess cut to .224" diameter and the web reduced on the outside and the sized in an appropriate die.

There are two things I wonder about:
1. the reduced internal capacity (room taken up for primer and web)
2. If a small pistol primer would dislodge the bullet too early for the powder to properly ignite the powder.

I am thinking a 40 grain lead bullet at 1250 fps (duplicating that average high velocity 22LR ammo). The bullet would have to be rebated much like the standard 22 ammo bullets and probably crimped in place with a collet style crimping tool. (the outside of the case is the same as the bullet diameter)

Since the priming compound for the rim-fire is no longer easy to get (primary explosive) I figure it might be a challenge to make a center fire version.

I don't expect it to be marketable or even cheaper to load than the rim-fire cases are to buy. Just an idea that I am considering.

the 22 epperson cricket by a fellow with the screen name Vibe is the only one i know of. look on w.saubier.com & other small cal. forums.I have thought about the same cartridge or maby even use the 25 acp as is. the lot to lot variations,lack of 22 ammo and discontinuation of rimfire cartridges make it an aggrivation sometimes.

Here's an old thread, maybe this can help you:

http://forums.accuratereloadin...=611106601#611106601

What you describe is pretty much the FN 5.7x28. You could shorten that case and use the same dies and reamer for your project. I can see a niche for a .9" case length version.

It was done about 1938 - 39 by Col. Askins, and Pachmayer

Called the caliber, 221 Askins.

They converted a Colt Woodsman to centerfire 22 LR.

J Wisner

I think the Askins cartridge was the .22 Velodog revolver round.

They took the velo case, and shortened it to the LR length. Then turned the rim down to the same as the LR case.
That way it would fit in the magazine, and chamber.

J Wisner

Fellas
Some interprizing soul will find a market for for reloadable 22 centerfire cartridges, such as the modified 22 Velo Dog.
The ammo companies don't seem real interested in ramping up rim fire production. Reminds me of Colt's ignoring the poor quality control in production and producing what the public wanted.
Colt had the market then and now there's dozens of 1911 manufacturers.

Jim

I seriously doubt there will ever be a real market for a 22LR center-fire round but it is an interesting thought experiment. Once I get some of my other projects done I might even make the attempt at making a center-fire conversion kit for my old 581 Remington. Then if it turns out to be less than I want I can always go back to rim-fire.

The major set backs that I foresee are:
1. the lathe work required before the sizing process.
2. the sizing dies and shell holder
3. making a die for casting the rebated bullets.
4. making the collet crimper for the loaded case.
5. having it acceptable in actual competitions in place of the rim-fire round.

If I could get number five done then it would be more likely to be a success... but some manufacturers would have to get on the band wagon too in order to make it viable for the mass market.


Keep in mind that I am thinking of a direct center-fire replacement for the rim-fire cartridge.

Take a 22 Hornet case, shorten it to the length you want (below the neck), neck what's left to .224". Inside/outside neck turn if necessary. I suppose rim dia. could be reduced slightly as well. Wouldn't surprise me if it's already been done. Probably very similar to the one mentioned above by J. Wisner.

.22 JGR I believe was made from either a shortened Hornet case with rim turned off or possibly the .32 ACP necked down to .22. It came from Canada as I recall.
C.G.B.

It is relatively easy to neck a cartridge down to 22 caliber but that is not what I am after. I am after an exact replacement for the 22 LR (size and shape) in a center-fire case.

so you mean to possibly swage the 25 acp into a 22 rimfire size cartridge. i hadnt thought of this. i am pretty sure it can be done with the proper dies.

quote:

Originally posted by Phil Brousseau:
so you mean to possibly swage the 25 acp into a 22 rimfire size cartridge. i hadnt thought of this. i am pretty sure it can be done with the proper dies.

Yep! that's what I am thinking about. That's why there will be lathe work involved. I will have to trim the rim to the right diameter and thickness and cut away a bit just forward of the rim (web area) to enable the case to be sized down to the right diameter all the way to the rim.

Since the bullet and case are both .224" in diameter I will need to make a collet crimping die to crimp the rebated bullets into the case.

Maybe make new cases to your spec from steel via cnc machine instead of all the bother of forming cases like you said with the added benefits of a steel case? Make them strong capable of higher pressure and velocity. You could sell them and hotcakes wish they went so fast.

Didnt Cooper Arms market a .22 centrefire rifle and supply turned brass cases ? I am pretty sure I got a turned brass case off them back in the late eighties/early nineties???

quote:

Originally posted by muzza:
Didnt Cooper Arms market a .22 centrefire rifle and supply turned brass cases ? I am pretty sure I got a turned brass case off them back in the late eighties/early nineties???

Muzza,

I have never heard of any 22LR center-fire cartridges but I will do some searching for Cooper arms to see what I can find. The problem I ran into when searching 22 center-fire cartridges was that there are so many from the 219 Zipper to the 220 Swift. In all those cartridges I didn't find any that duplicated the 22 LR case.

If my memory is correct , the case was a rimmed one that looked like a scaled down 22 Hornet more than a 22LR. Was definately a centrefire , and definately lathe-turned and definately Cooper that supplied it .

Hope thats of some help , although not a lot to go on. Good luck.

The 22 squirrel is a shortened hornet case just under an inch long.

quote:

Originally posted by DenisB:
The 22 squirrel is a shortened hornet case just under an inch long.

Yes but there is even more difference between the Hornet case and the LR case than with the 25 auto.
The 25 auto needs .015 trimmed from the rim (.030 off the diameter) then thin it by .003" and trim the bottom of the case (just above the rim) .004" (.008 diameter) and then thin the web so it can be swaged. To make the cartridges identical you would need to use an inside reamer to clean up the web and the size and trim to length. It would be easy to run a few hundred through a CNC machine but I only have an old manual lathe. It will not be hard to run off a few to get some to play with and see how much powder it takes to get the 1250 fps with a 40 grain bullet.
I am thinking 1 - 1.5 grains of HP-38. That might be too much but only actual tests would confirm it.

the 22 cooper centerfire is just like the 22 mag rimfire size wise. it is not on the hornet case.

quote:

Originally posted by Phil Brousseau:
the 22 cooper centerfire is just like the 22 mag rimfire size wise. it is not on the hornet case.

So the Cooper uses a regular .224 bullet and it fits inside the case - not like the rebated bullet used in the 22 LR?

yes. i think what they made was a reloadable 22 magnum. small rifle primer& regular cup& core .224 bullets.

Have you actually taken the time to place a small rifle primer next to a 22LR case?
Talk about no brass at all right where it is needed.

Have you looked at the 25 ACP case? The difference between the two is just .054" diameter. That means cutting only .027" off around the primer pocket (less than the extractor groove). The 25 ACP case already has the primer pocket in it and the pressure we are talking about is less than 20,000 psi.

The case is fully supported by the chamber in a 22 so with a modified 25 ACP it will have thicker brass than the 22 LR rim has.

For a better comparison compare your SP primer to the rim of the 22 LR.

Years ago, I developed different versions of low velocity ammo for the .22 Hornet.

Some for indoor shooting practice.

I tok some cases, and opened them up by expanding the neck to the same diameter as the body.

I made brass inserts - of varying lengths - to fit into the case.

The longest of these went just under the neck junction.

I drilled a hole through them for the primer flame to go through.

After the inserts were glued into the cases, I ran the cases through a sizing die.

I used mainly Bullseye with them and they worked great.

I have moved house twice since then, and see to have lost my notes on them.

I took my grandson to a gun show over the weekend, bought a box of Coliberi (?) 22 RF with priming compound only, no powder. The data sheet says 500 fps for the smaller bullet. Now I wonder if something like that could be developed using a centerfire primer...

Extremely intersting thread. I would have never thought of this had I not read this. Cool!

I have built two forming dies and a final sizing die. I have a primer seater, a decapping pin and a case turning plug.
I have completed one case - I now have a center fire 22 LR case. I have looked for bullets or casting molds for them with little success. I may have to make my own molds to make the bullets and I need to make a crimper.

The case chambers nicely in all of our 22's. As soon as I get some bullets and more cases completed I will load some up to fire through the chronograph to make sure I get around 1250 fps. The gun I will be using to test them is a Contender because it already has center fire capability.