What the heck is .251 TCR? Well, lemme tell ya...

[dverna]

I love .32 S&W long, and have a couple of them. It's accurate, and can be a fine small-game cartridge. But the goal was a re-loadable alternative to rimfires, and .32 really doesn't do the job of replacing the whole spectrum of .22 rimfires, especially in the field of super-light gallery loads. This cartridge can be loaded to emulate .22 Colibri or 6mm Flobert at the low end, all the way up to hotter than .22 Magnum at the high end. It's just a better fit for the mission than .32 S&W Long.

OK, now I understand.

When the .22 shortage hit, I was going to get a .32H&R or .327 lever action but never could justify it. I was sitting on about 30k .22's and sold half of them at stupid prices (about $1500). After some thinking, realized, the .32/.327 was a want and not a need. Spending $750+ was silly. The .38/.357 guns I had would keep me shooting inexpensively for a long time. Decided to stock up on SP primers and powder instead. I recently added more .22 inventory now that prices are less than $.04 a round.

I admire your skill. You came up with an elegant solution to address your needs. It would be dandy to have a companion rifle for small game.

Good luck on the rifle build!

[Chev. William]

I have to wonder how hard (easy ?) it would be to convert most any .22 mag revolver to this cartridge (maybe lengthen the casing a little to match the .22 mag length of 1.055" ?)? Have to modify the firing pin... Replace or bore the barrel... Cost prohibitive for me, but then again, no more headache of .22LR unobtanium situations. Bullseye and Unique could shine in this, I would think. Many possibilities...

Buy a Lothar Walther Cr-Mo Steel 23+ inch long Barrel blank in 25ACP/6,35 Browning which has about a 1 turn in 9.8 inch twist rate; cost about $230.
Convert a Ruger 'Single Six' .22 CAL revolver from RF to CF and Fit a new barrel to it; cost about $300 plus the cost of the revolver.
Ream and lap the Cylinder's chambers to .251" ID, then chamber it with straight wall piloted reamer to .2795 inch to fit your cartridges; cost about $100.

I went a bit further and have a Custom Ruger "Single Eight" with multiple 8-shot cylinders fitted to it and chambered to:
1. .25ACP (tapered wall chambers) that works with factory .25ACP but allows the Case wall to bulge with hot reloads.
2. .25ACP Straight Cylinder Wall Chambers (SCWC) at .2795" diameter that shoots hot reloads without the bulged walls.
3. .25ALR SCWC for a case length of .960 inch.
4. .25MACP SCWC for a case length of 1.055 inch.
5. .25ALS with tapered wall chambers for a case length of 1.125 inch.
6. .25ALS with SCWC for a case length of 1.125 inch for hot reloads.
7. .25ALRM with tapered wall chambers for case length of 1.250 inch.
8. .25ALRM with SCWC chambers for case length of 1.250 and hot reloads.
The maximum loaded cartridge overall length for these cylinders is 1.410 inches. any longer COAL fouls the barrel forcing cone in my revolver. It has a 10-5/8 inch long tapered barrel fitted to it. The cylinders are made from 'Stressproof' ANSI 1144 Alloy Steel and were purchased mostly from Numerich arms at about $160 each.

The Revolver shoots Much better than I can, as a friend used it to hit a 12 inch gong repeatedly at 100 yards range.
To date I do well to hold a 3" diameter pattern one handed at 7 yards.

I also have a Ruger Standard Auto MKII Pistol converted to .25 ACP with a 8-1/8 inch barrel. This conversion and Barrel were done by John Taylor of 'Taylor Machine' in Paliup(sp?), WA. I Strongly Recommend him for this work.

Best regards for the Holidays,
Chev. William

[Chev. William]

This seems a mighty good idea for revolvers if you can build your own or have one made.

This is the exact route some people are following to make a reloadable .25 Stevens Rimfire, for which countless thousands of boys' rifles and Stevens 44 small game rifles still exist, but for which ammo is so scarce as to bring over $1.00 a round on Gunbroker. Just trim the swaged-down Hornet case to 1.125" and use a 65 grain .258 cast bullet. (Yes, I know Barnes says .251 but all the Stevens and Remington barrels I've collected are .257 plus or minus.)

Occurs to me to add that, before the advent of smokeless high velocity .22s, the .25 Stevens was considered the acme of small game rimfires, so a centerfire recreation of it is very much in order.

The few J. Stevens marked .25 Stevens barrels I have seem to measure around .251" area for Groove diameter. the Bores seem to vary a bit more, from about 246" to about .249" according to slugs my gunsmith did for me.

Chev. William

[Chev. William]

Tinker Pearce,
Very Interesting development!

I have been working on a family of .25 CF wildcats based upon .25ACP/.25 Stevens dimensions for body and rim diameters made from both .22 Hornet and 5.7x28mm parent cases.
I also swage the cases down to .278" max diameter, typically .276" to .277" then trim them to the various lengths I am working with.
With the 5.7x28mm case parent I end up wiht a rim about .314" diameter without need to turn them down. You might look into trying the 5.7x28mm case for your cartridge as I find it swages much smoother because it is Polymer coated as found. I do use multiple stages of swage dies for greater Yield with lower press force required poer stage.

Please consider submitting your .251TCR cartridge to "Ammoguide Interactive" for inclusinon in their cartridge master listings (ammoguide.com) and then add your load data to the Listings.

In my longer barrels I find BE-86 gives more Velocity with reasonable pressures so perhaps you might consider trying a pound of it in your cartridge.

In .25ACP cases, I have fired 3.0 and 3.1 grains of BE-86 behind 50 and 63 grain bullets with an estimated pressure of around 29,000psi. I figure my 8-shot 1144 cylinders can handle up to around 43,000psi ultimate stress due to the locking cut in the side of the cylinders, it is the "thin point" in the chamber walls.

I estimate a working peak Pmax of 30,000psi for my revolver loads and use 25,000psi Pmax for the Auto Pistol so far.

Best Regards,
Chev. William

[Tinker Pearce]

You have some very interesting projects there yourself! The TJ's barrels are a 1:14 twist; it's be nice to have something a bit tighter. I typically use 4140 for my cylinders; I lined the stock cylinder for my test gun, but the second gun I just put together has a bespoke 5-shot cylinder. I did a six-shot originally, but didn't like the thinness in the lock notches; with the five-shooter they are offset enough to avoid this issue. It's a converted Well's Fargo repro, so the cylinder is pretty small diameter.



I need to look up Ammoguide; I was wondering if such a site existed.

[Tinker Pearce]

Wow... Ammoguide.com is a real time-travel experience! That is one seriously antique website. I tried to use their .app to add a cartridge, and repeatedly got a '404 error' when I tried to download it. Any helpful thoughts?

[303Guy]

Wow... Ammoguide.com is a real time-travel experience! That is one seriously antique website. I tried to use their .app to add a cartridge, and repeatedly got a '404 error' when I tried to download it. Any helpful thoughts?

One has to be a paid up subscriber. I've been a subscriber for years.

Care to build me a lightweight 25 hornet break action? Or a falling block with side eject? That's been an idea I've had for some time.

I'm intrigued by the concept of lightweight pellet type projectiles. For that the TCR would be ideal I should think. It looks to be a well proportioned cartridge and uses the thicker case body rather than a stretched out already thin hornet neck so makes a lot of sense.

I'm wondering how a 410 barrel insert in TCR would work out? With a long barrel insert (not full length) it should be pretty quiet.

[Tinker Pearce]

I bought a subscription before I even tried it.

I'm a strictly amateur gunsmith, do building for others is a no-go.

[Chev. William]

303Guy,
Hmmmm
A Falling Block action with Side Eject feature.
That sounds like a very Complicated mechanism to drop the Breech Block pull the empty back and kick it to the side to eject.
Were you thinking of loading it through the side port or using a repeater function for the reloading mechanism?
I guess it would not be as "Monkey Motion" as the Luger Pistol trigger system.

Chev. William

[salty dog]

Thanks for the data. That's quite a variety of bullet possibilities.

[uscra112]

Frank DeHaas' "Vault Lock" falling block design side ejects.

One thing that is interesting about the .250 groove cartridge is that there's a jacketed hollowpoint for it that will work at pistol velocities. All the .257 jacketed types are made for .257 Roberts velocities and up.

[Tinker Pearce]

Frank DeHaas' "Vault Lock" falling block design side ejects.

One thing that is interesting about the .250 groove cartridge is that there's a jacketed hollowpoint for it that will work at pistol velocities. All the .257 jacketed types are made for .257 Roberts velocities and up.

That was the main reason I selected .251 instead of .257- the cartridge is conceived to work in pistols, and short-barreled (4") ones at that. The existence of the 35 gr. Gold Dot sort of sealed the deal.

[uscra112]

Early on in my quest to make .25 Stevens rimfire out of .17 WSM rimfire, I bought a .25ACP liner from TJ. (There's information on the web, as well as in Barnes, that claims the Stevens cartridge uses a .251 bullet, but it turns out to be bunk.) It's stored away, since I held on to it too long to return it. Now you're making me think about it digging it out.

[Tinker Pearce]

Early on in my quest to make .25 Stevens rimfire out of .17 WSM rimfire, I bought a .25ACP liner from TJ. (There's information on the web, as well as in Barnes, that claims the Stevens cartridge uses a .251 bullet, but it turns out to be bunk.) It's stored away, since I held on to it too long to return it. Now you're making me think about it digging it out.

If'n you don't let me know... might be we could work out a thing.

[uscra112]

Check yer email.

[Tinker Pearce]

Check yer email.

Replied

[303Guy]

303Guy,
Hmmmm
A Falling Block action with Side Eject feature.
That sounds like a very Complicated mechanism to drop the Breech Block pull the empty back and kick it to the side to eject.
Were you thinking of loading it through the side port or using a repeater function for the reloading mechanism?
I guess it would not be as "Monkey Motion" as the Luger Pistol trigger system.

Chev. William

The idea is that the body and block are open top and side or maybe side only. Side only would allow for scope mount while top and side would make for a more open action for easier loading.

I must look up the "Vault Lock" falling block.

The Vault Lock is exactly what I had in mind with a cylindrical falling block (ease of manufacture) , engaging below and above the breach. For smaller low power cartridges (like the 22 hornet) I envisioned part of the top support omitted on the port side to create more access space. My conceptual design uses the more conventional lever down to open the breach.

https://www.bevfitchett.us/rifle-plans/info-ifc.html

[Chev. William]

Tinker Pierce,
Congratulations on your Published .251 TCR on 'ammoguide.com'; it was announced in the January 2020 Newsletter.
" New on AmmoGuide...

(Most recent at top)
1069. .40-60 Marlin New
1068. .251 TCR New Wildcat!"

Being based upon swaged down .22 Hornet Case, I guess the Maximum pressure for the cartridge would be about 40,000psi Pmax MAP (SAAMI procedures) with reduced pressure for the older, small frame revolvers you have converted.

Perhaps you will post some of the Loads you have developed along with their Muzzle Velocities and details of what the 'Test Firearm' is for each load?

Best Regards,
Chev. william

[Tinker Pearce]

Tinker Pierce,
Congratulations on your Published .251 TCR on 'ammoguide.com'; it was announced in the January 2020 Newsletter.
" New on AmmoGuide...

(Most recent at top)
1069. .40-60 Marlin New
1068. .251 TCR New Wildcat!"

Being based upon swaged down .22 Hornet Case, I guess the Maximum pressure fo rthe cartridge would be about 40,000psi Pmax MAP (SAAMI procedures) with reduced pressure for the older, small frame revolvers you have converted.

Perhaps you will post some of the Loads you have developed along with their Muzzle Velocities and details of what the 'Test Firearm' is for each load?

Best Regards,
Chev. william

Thanks for the calculations- I'm not equipped to measure the pressure. I've posted a comprehensive listing on Ammoguide, but here's a selection of tested loads:

31gr. H&N Grizzly LHP- This is actually an airgun pellet shaped like a bullet.
1.0gr. Power Pistol 257 fps. 4.6 ft/lbs SD: 28 fps.
Gallery load. Flies straight and groups well at 15 feet
2.5gr. Unique 843 fps. 49 ft/lbs SD: 79 fps

2.8gr. Power Pistol 1104 fps. 84 ft/lbs SD: 57 fps

35gr. Gold Dot Hollow Point
2.7gr. Power Pistol 769 fps. 41 ft/lbs. SD: 41 fps

3.5GR. Unique 1024 fps. 82 ft/lbs SD: 24 fps

3.5gr. Power Pistol 1214 fps. 115 ft/lbs. SD: 38 fps

4.0gr. Power Pistol 1464 fps. 167 ft/lbs. SD: 54 fps.
These need to be loaded with great care; any inconsistency with crimp or seating depth will result in yawing or keyholing (I haven't actually measure the proper OAL... oops.)
Not a terribly stable bullet at these velocities...


35gr. LWCHP- These were swaged from the GDHP listed above.
2.5gr. Power Pistol 726 fps. 45 ft/lbs. SD: 45 fps.
Need to see how hard I can push this bullet. The greater surface area might keep it stable.

38gr LSWC- I swage these from ¼” lead wire.
2.0gr. Power Pistol 698 fps. 41 ft/lbs. SD: 41 fps.

2.5gr. Power Pistol 875 fps. 65 ft/lbs. SD: 26 fps.

2.7gr. Power Pistol 912 fps. 70 ft/lbs. SD: 24 fps.

2.0gr. Red Dot 1184 fps. 118 ft/lbs. SD: 35 fps.

50gr. PPU FMC
2.7gr. Power Pistol 831 fps. 77 ft/lbs SD: 13

3.5gr. Power Pistol 1108 fps. 136 ft/lbs SD: 21

55gr LRNFP Rimrock
2.5gr. Red Dot 868 fps. 92 ft/lbs SD: 38
4.0gr. Power Pistol 1157 fps. 163 ft/lbs SD: I forget...

57gr SPJSWC- I swaged these from cut-down .243 rifle bullets.
3.8gr. Power Pistol 1078 fps. 155 ft/lbs SD: 13

The test gun for all loads is a 3-1/2" Uberti 1873 BP converted to .251 TCR. There is a second gun based on an 1849 Wells Fargo reproduction, with a new 3-1/4" barrel and a bespoke 5-shot cylinder made from half-hard 4140. Also converted to a sheathed spur-trigger... that trigger-guard was tiny!

[35 Whelen]

This is a fascinating thread/project and I humbly admire your prowess in metal working. Please keep us updated!

35W