Going through a box of brass and ran into this. It is labeled .351 trimmed and ready to load. It is headstamped R P 357 Max. It is trimmed 1.372 to 1.374. It has been shortened and looks like it has been put in a lathe and turned to semi-rimless cartridge. It is pictured with a standard 357 max R P Case. It appears to be made from new brass. If it was turned on a lathe it had to be very labor intensive. I am guessing I have 140-160. What is the name of the cartridge? Demand?

All input appreciated

Thanks
Doug

Those have been made into 352 WSL cases
(.351 Winchester Self Loading (Rifle)

Case length is listed at 1.375.
Somewhat odd bullet dia at .352
The case is a semi-rimmed design and does headspace on that very slight semi-rim. That allows for crimping of the bullet into the case.

They did a nice job. Even put a factory style extractor groove cut in the case with enough clearance so as not to jam the extractor against the case when chambered.

The Winchester Model 1907 semiauto rifle is what they get used in.
Blow-back operated design w/a detachable box magazine. All of the WinSLR series used the same design. Very heavy recoil spring and heavy breech block = heavy weight rifles for their calibers.

Older stocks of factory ammo are still around if you look (box/50) but the prices have really gone up due to collectors and shooters.

Reloading is what most people that like these Winchester Self Loaders do.

The 1907 in .351 is probably the most popular of the bunch.
The 1910 in .401 is fun to shoot. I load for that one and make cases from 7.62x39mm brass.
The 1905 Model was offered in two even more obsure calibers. The 32WSL and the 35WSL.
But brass can be made from existing common types and they can be put back on the range.

The Model 1907 was popular as a Police and Corrections Facility firearm.

Bullet diameter is actually 0.351”, cast bullets are typically sized 0.352”. I have some of the .357 Max converted cases, and those do look nice from the photos. This is not a particularly difficult job for one with a lathe as I understand it.

Lately, I have been converting .223 Rem into .351 WSL for shooting at the range or woods use.

Buffalo Arms has a listing for these cases of $63.00 per 100, or 79 cents each. They are apparently out of stock currently.

I have used .357 Max., .357 Mag. and .223 brass for the .351 Win. I think the new .350 brass would work just fine. Trim it to headspace on the case mouth and you would be good to go.
C.G.B.