Help with 32 S&W Long to .25 caliber conversion project.

[Steppapajon]

The idea of a 32 S&W Long necked down to .25 caliber has been kicking around in my head for 8 or 9 years. Hoping to load 30-60 grain cast between 850 fps to 1400 fps.I want to chamber a break action single shot rifle. I know where I want to end up but I don’t know how to get there. I have a couple of ideas so I am going to post them and let the community guide me in the right direction. I know there are some extremely knowledgeable people on this forum. Thought #1 is to shorten a 25-20 sizing die by .400”. If I run a 32 S&W long case thru the shortened die I get a case with the same length neck as the 25-20 but with a body about .400” shorter. Option #2 I shorten the die by .300”. In the scenario I get a shorter neck but a longer body. Option #3 is to mimic the .256 WinMag but use a 32 S&W Long case and make a mini version.
The second part of the equation is the firearm. I have a Savage 219 that I could have a barrel made to fit. I have a H&R Pardner SB1 that I could have a liner installed in and chambered to the new cartridge. I have a Steven’s 94F and a 94N 20 ga. that I could have a stub barrel made for. So I need some ideas from you guys. I am sure I left out a lot of information but hopefully there is enough to start a conversation. I am attached a photo of some of the drawings I made. That should help convey the ideas better.

[Fast Asleep]

You should take a look at the 25 Schutzen which is the 32 H&R necked to 25 caliber. You can buy dies for this and a rental reamer is also available. I am converting Remington #2 Rolling Blocks in 32 RF to this round using Redmans liners. The breach block is converted to CF as well, but no change for the extractor.

[Steppapajon]

@Fast Asleep,
Can you point me in the right direction for the dies and reamer? I am coming up empty when I search for them.

[Texas by God]

First, make sure that you have a good supply of parent brass. At present, 25-20 brass is rare.
Second, check the firing pin diameter of the donor shotgun. Small is better; the H&R/NEF usually has a small pin diameter. This is important for a small primer cartridge.
Good luck with your project, and we like Pictures!


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[Fast Asleep]

4D has rental reamers and I thought CH had dies—but was mistaken. I use shortened 25-20 dies to neck size and seat bullets.

[Fast Asleep]

Also—I have a sizer reamer that was used to make the die for initial brass forming.

[Jedman]

I have made more than a few successful wildcat rounds with the same idea. I like your plan no. 1 idea,
The OAL difference between the 25-20 WCF and the 32 S&W long is about .410 and when you reduce the neck diameter and shoulder on a strait walled case the length of the sized brass grows a little in length. So shortening the 25-20 size die by .400 should give you a well formed case with the same neck as tho 25-20 and a OAL case length of approximately..930. Your cartridge would look like the middle cartridge in your drawings.
A
Sleveing break action shotguns to make single shot rifles has become an obsession with me. I have used H&R toppers and pardners , Savage 94’s & 94-78 and many others for the conversions.

When working with a small rifle or pistol primered brass , you really need a small firing pin diameter receiver or you will have trouble with primer flow and trouble opening the action after firing. If you have a H&R Pardner SB1 with the small dia. firing pin to use that is your best choice if you want to keep it simpler and less work for the base shotgun to use.
If you are working with a 20 ga. barrel you might get lucky and find a pre chambered take off barrel in 25-20 that can be lathe turned to fit a 20 ga. barrel and save a lot of work.
If you are working with a larger than 20 ga. barrel you will most likely need to start with a barrel blank large enough in diameter to use and then ream with a 25-20 reamer to the depth you need and have the rim recess cut for the 32 S&W long rim size.
With a H&R shotgun, ejectors for the 22 hornet are still available and can be cut to fit the case head and rim size of the 32 brass.
If you use another brand shotgun for your project you may have to either weld up the ejector or make a extension that can be soldered to the original ejector and then reshaped to work with the smaller cartridge head size.
I LIKE YOUR IDEA ! Jedman

[Shawlerbrook]

Just love these projects. Please keep us informed with your progress.

[John Taylor]

Sounds like a fun project. I would use a TJ's liner. Firing pin diameter should be .060" to .080". If your going to use an old shotgun like H&R it is easier to stub a barrel than use a liner. Liners are made from 4130 and new barrels are made from 4140 heat treated steel which is a bit tougher. It is a little tricky to bush the firing pin on single shot shotguns .

[Steppapajon]

Taking into account the great feedback, I spent the weekend digging deeper on my options. The firing pin on the two Steven’s shotguns and both over .110”. The chamber on the .410 is bigger than the 7/16” barrel liner. Finding a .257” takeoff donor barrel with a 1 in 14” twist has proven impossible for me. I looked at new barrels but for the cost it occurred to me I could buy a new CVA Scout and put a liner in it. I am thinking the 350 Legend or the .300 blackout. Is there anything I am missing? Can a 350 legend be drilled for a 7/16” OD liner without any problems.

I have settled on the specs. For the round. I decided to send the drawing to one of the reamer manufacturers and have a custom made. Any critiques are more than welcome. I appreciate all of the input so far!

[MarkP]

IIRC when looking at reboring rife bbl's the shops were wanting 0.110" wall at the muzzle. The 25 cal liner @ 7/16" O.D. is probably reyling on the hoop strength of the original barrel, that of course depends on the max operating pressure of the new cartridge.