Converted .17WSM to .25 Stevens rimfire

[ndnchf]

I don't even own a .25 Stevens rifle. But I've read about different ways to make brass, including conversion from .17 WSM. So out of curiosity, I decided to see if it was possible.

First I had to make a simple fixture to hold the case to pull the bullet and expand the case mouth. Then a 3-step mandrel was made from a 1/4" bolt to expand the mouth from .168" to .250".

It took some trial and error, and a few wrecked cases - but I figured it out. It really comes down to annealing the case mouth thoroughly first.

The first couple cases I did, I tried to anneal them, but was concerned about heat getting to the priming compound. I didnt heat them enough and they both split. This time I filled the case with new crushed walnut media to just below the neck. This provided an insulating barrier. Then I held it at the base with a wet, folded paper towel. This helped keep the base and my fingers cool. The case mouth was rotated in the tip of a propane torch flame for 15 seconds. Then quickly the walnut media was dumped out and the case mouth, upside down was dunked into a shallow bowl of water to quench. I was careful not to let water get deep inside.

After annealing, the 3-step expander was put in the drill press, and the case into the fixture that was clamped in a vise anchored to the table. With Imperial sizing wax applied to the mandrel, it was slowly and repeatedly worked up and down until the mouth was fully expanded.

The case length came out at 1.175". The original .25 Stevens case was 1.125". So it was a simple matter of trimming it back .050" to make a perfect .25 Stevens case.

Now that I know it is possible, I may keep my eye out for a rifle :p

[Mk42gunner]

The only part that makes me nervous is the annealing of a primed case. Your use of walnut media as an insulator seems to take care of that issue.

I have read that the .17WSM cases are made a lot stronger than the old rifles were designed for and may have trouble getting reliable ignition.

I know I have passed on a few old single shots in .25 Stevens or .25-10 due to unobtainium ammo.

Robert

[ddixie884]

Cool................

[ndnchf]

I too have heard of ignition problems with these. It seems to primarilly be with the smaller boys rifles. But larger rifles like a Stevens 44 or #2 rolling block may work better. I passed on a really nice low wall a few years ago. If I were to come across another, I'd be more inclined to go for it.

[Shanghai Jack]

A true experimenter seeing as how you don't even own the rifle . . . yet

It appears that you have it clamped to a drill press - are you spinning the expanding mandrel or just using it like in lieu of an arbor press.

[Shanghai Jack]

I too have heard of ignition problems with these. It seems to primarilly be with the smaller boys rifles. But larger rifles like a Stevens 44 or #2 rolling block may work better. I passed on a really nice low wall a few years ago. If I were to come across another, I'd be more inclined to go for it.

I've heard this as well but don't understand the mechanics of the issue. Can someone explain

[ndnchf]

A true experimenter seeing as how you don't even own the rifle . . . yet

It appears that you have it clamped to a drill press - are you spinning the expanding mandrel or just using it like in lieu of an arbor press.

It is not spinning. It was simply a way to both firmly anchor the case and have an easily controllable way to run the 3- diameter expander in and out.

[Shanghai Jack]

You know there used to be a place called Federal Arms that sold primed 22 rimfire brass. I wonder if Winchester would sell primed but not yet charged WSM brass. I'm guessing not due to liability issues

[ndnchf]

I've heard this as well but don't understand the mechanics of the issue. Can someone explain

I think it comes down to mass and kinetic energy of the hammer. In some cases the boys rifles just dont have enough kinetic energy to fire the tougher .17WSM rims. I've encountered a similiar issue with other reloadable big bore rimfires Im working with. .22 starter pistol blanks work fine in my 32s and 44s, but sometimes puncture in military .56-50s. For these I use tougher Ramset blanks. They stand up to the heavier hammer blow.

[3006guns]

I think it comes down to mass and kinetic energy of the hammer. In some cases the boys rifles just dont have enough kinetic energy to fire the tougher .17WSM rims. I've encountered a similiar issue with other reloadable big bore rimfires Im working with. .22 starter pistol blanks work fine in my 32s and 44s, but sometimes puncture in military .56-50s. For these I use tougher Ramset blanks. They stand up to the heavier hammer blow.

Too bad you're so far away. I have a box of .22 blanks for a Ramset (or similar) that I've been trying to give away for about five years.........

[uscra112]

The .17WSM brass has to be much stronger because the pressure is so much higher than even current .22 LR. The older boys' rifles were designed when rimfire ammo had copper cases, and probably never exceeded 8000 psi.

(Modern .22 ammo seems to be loaded to no more than 12,000 psi, in spite of the SAAMI specs. I think this is why it still functions in these old rifles.)

[uscra112]

Here is the gadget I made for annealing. No media inside the shell, but rather it is stood up in a little cup of cold water and rotated at about 45 RPM to get uniform heating. Doing both would be even better.

[uscra112]

I am shooting these reformed cases in a Stevens 44, which has plenty of energy due to the much heavier hammer and stiffer spring. I also have a Stevens Model 83 bolt action single shot from about 1938 that reliably fires them. Most Model 83s were .22, but a few escaped the factory as .25s. Possibly the last factory rifles ever made for the .25 Stevens. If you see one, grab it.

[hrt4me]

I may have to try this, as I have a Remington Rolling Block No. 4 chambered in .25 Stevens rimfire...

[Plate plinker]

Your annealing solution could be refined with a split block of aluminum that has a series of holes to clamp cases. Rig up a holder that keeps the bases in bit of water, then easily flip them to quench if desired. Cool idea to work with a old cartridge.

[ndnchf]

I now have a centerfire breech block. I've made about 50 centerfire cases from .22 Hornet. It shoots very well.

[yeahbub]

Not sure this is a possibility, but I wonder if, after having fired the rimfire cases, they could be saved, and converted to centerfire by:

1. Being annealed and internally cleaned (chemically?), using a small pistol primer-sized swage tool to indent and stretch the head material to form a primer pocket.

2. The void in the hollow rim and the gap between the case wall and primer hump soldered/brazed up with a measured quantity of low temp/high strength solder like High Force 44 (Brownell's?), using enough to fill all voids and provide a strengthening fillet radius from the top of the primer pocket hump up the side of the case wall, producing a solid-head case approximately .150-.180" thick.

3. Center-drill a flash hole .075-.080". (I use a small primer pocket drill guide made from a 1/4-20 socket-head set screw center-bored through 5/64" and the threads on the end turned down to .172 with a stop-nut for depth and to hold it square to the case head when I convert Berdan cases to Boxer.)

Sound like a plan? I have no access to any .25 Stevens stuff, but if a center-fire version ever came about, I might take up squirrel hunting again. The .22 RF is good, but it could be better. An inside-lubed boolit of my own choosing in a larger caliber I can reload calls to me.

[SSGOldfart]

Very nice job I might get the girl back on the firing line again yet.
I still have a box of 25 rimfire for my wife's 25 Steven model 1915.;-)

[ndnchf]

The .25 Stevens centerfire I made from .22 Hornet brass work great. The little rifle is quite a tackdriver!

[uscra112]

Show 'em the converted Hornet case you made that uses the 6mm acorn blank as primer. No change to breechblock required.

[ndnchf]

Here is the .25 Stevens case made from .22 Hornet, then converted to rimfire. It uses a .22 acorn blank as the rimfire primer. They are a bit of work to make, but work well.

[uscra112]

They're less work to make than converting the .17WSM, in my book. But it does require a lathe.

The .17WSM rim has a radius behind it. Most old rifles will be loose enough not to notice, but I had to chamfer the chamber mouth of my minty Model 83 to accept them. A modified Hornet case doesn't have that problem.

[ndnchf]

They're less work to make than converting the .17WSM, in my book. But it does require a lathe.

The .17WSM rim has a radius behind it. Most old rifles will be loose enough not to notice, but I had to chamfer the chamber mouth of my minty Model 83 to accept them. A modified Hornet case doesn't have that problem.

Yes, I agree. The .17 WSM cases are quite thick in the rim making reliable ignition in small boys rifles problematic. The acorn blanks or centerfire cases have no reliability issues.

[yeahbub]

can somebody fill me in on the difference in performance between .25 Stevens CF and the .25 Hornet wildcat?

[uscra112]

The .25 Stevens round was originally a black powder rimfire number, and MANY rifles made for it cannot stand loads in excess of 9500 psi or so. Subsonic, in other words. Standard bullet was 65 grains, plain lead.

The .25 Hornet is a centerfire round with almost double the powder space and is usually loaded 25,000 psi and up for MV in excess of 2000 fps..

About WW2 Allyn Tedmon was lobbying for a "high-speed" .25 Stevens. (1400 fps or so) but nothing came of it. It would have been very unsafe in your typical Crackshot or Favorite, is probably the reason. Today we can do it, with the reservation that it be used only in strong actions like the Model 44 or the Model 83. And I will, once I'm back on my feet.

[yeahbub]

Thank you, uscra112. I was hoping for just such a development as a high-speed Stevens in center fire, but a number of older, weaker actions have been converted to center fire, so any newer higher pressure round would need a longer case for safety's sake, as is the custom for the magnum pistol rounds. There was a thread on this site where someone was working on reviving the .25 Stevens as a CF, complete with pressure data and cartridge drawings. Can't remember where, though.

[uscra112]

One way to ensure that high-speed loads aren't used in weak boys' rifles is to build them in converted .17WSM cases. They are so thick and hard that only full-size rifles like the Stevens 44 and 83 models will fire them. But the process is very labor-intensive. I've got about 20 loaded to a theoretical 1400 fps, and another 70 ready to load, and they will all be fired in my Stevens 83, a rare bolt-action from about 1938. It's so much trouble to make them that I won't make anymore. I have a kit to reprime them if it comes to that.

My .25 Stevens 44 now has a centerfire breechblock; I will try high speed loads in it, too. Have about 40 converted Hornet cases ready.

Waiting for Spring (and for my back surgery to heal up) before I do any serious testing.

The only .25 RF boys' rifle that's easy to convert to CF is the Hopkins & Allen Junior (or 925). It's a true falling block, and I think it could handle a 1400 fps load, but no more. Favorites won't, but they're more difficult to convert, which in this case is a plus. A #4 rolling block might be safe, but it's another difficult conversion. I can't think of any other boys' rifle that I would have confidence in.

[BrassMagnet]

Here is the gadget I made for annealing. No media inside the shell, but rather it is stood up in a little cup of cold water and rotated at about 45 RPM to get uniform heating. Doing both would be even better.

This is so cool! Can you provide a parts list and source so we can build them?

[Bent Ramrod]

A Marksman #12 might be able to handle the conversion, lockup-wise, although that stingy little extractor and the mainspring might give trouble. A variant handled the .44 Game Getter cartridges, IIRC.

I’ve never seen a H&A/M&H falling-block in .25 Stevens. Always been .22 and .32 rimfires, with one centerfire in .32 WCF and the Scheutzen model in books in .25-20 Single Shot. I do recall a lengthy thread on the old Shooter’s site where somebody fitted a 922 action with somebody’s .25 caliber barrel and chambered it in .25 Auto. The thread ended rather abruptly after the guy increased the headspace past the danger level with ten shots or so. Apparently, the hardening of the parts on those is not well done.

I recall in “whatever became of” gun mag articles that the cartridge was judged as “no longer needed” after the advent of the .22 RF Magnum. The number of hunters head-shooting squirrels and grouse off tree limbs at 40 yard distances is apparently no longer judged to be a sufficient market for Big Ammo to bother with. Alas.

[uscra112]

H&A Junior receivers were malleable iron, just like all of the Stevens brood. Case hardened to resist surface wear, but that does nothing for the overall tensile strength, which is about that of a very mild steel. The SAAMI limit for .25ACP is ~18,000 psi. A "high velocity" .25 Stevens would be about 1400 fps, and assuming a 65 grain plain base bullet need not exceed ~12,500 psi. (QL calculation)

I've never seen a Junior in .25 Stevens in the flesh either, but they did catalog them as a "925' model.

The .25 was right when it was invented, i.e. during the black powder era. BP .22's were pretty wimpy, the .22 barrels fouled fast and were hard to clean, and the .25 had the added advantage of being internally lubed. Smokeless in the .22, (and the invention of hard wax lube), made it obsolete. It was never feasible to up the .25's performance because of all the weak rifles and pistols around.

The Marksman has the wimpiest hammer blow of any boys' rifle I've ever fooled with. Barely even marks the .17 WSM rims. I think it will handle 12,000psi OK, the thrust calculation isn't much more than the .32 RF. I've created a centerfire .25 Stevens "Marksman" by mating the front end of a Model 12 to a Model 101 receiver. No more than function-fired as yet, (see post #27). Won't spend much time on it anyway, the .25 barrel I have only rates a "fair".

[uscra112]

This is so cool! Can you provide a parts list and source so we can build them?

Not much to it. The gearmotor is one of dozens to choose from on Amazon

https://www.amazon.com/BEMONOC-Reversible-DC-Geared-Motor/dp/B01D2H4FOY/ref=sr_1_11?keywords=12vdc+worm+gear+motor&qid=1641670252&sr=8-11

The rest is a 4" electrical junction box and cover from the hardware store, , some wire, and a battery from my RC hobby.

I made the cup from aluminum bar stock on the lathe. I.D. is 1/2 inch, so it'll take anything up to the common .30-06 base diameter. To make it watertight, after assembly I drizzled some thin polyurethane into it and let it harden.