Adding a Rim to Rimless Cartridges

The Mauser 1871 was the first rifle designed by the Mauser brothers to be adopted by the Imperial German Army. It fires a large bore black powder cartridge, 11.15x60mmR, commonly known today as 11mm Mauser or 43 Mauser. To reload for these old rifles, there are die sets available as well as bullet molds. However there are only 1-2 makers of brass cases and they are either out of stock or very expensive when in stock. As an alternative, I'm experimenting to convert other cases to work, both 300 Winchester Magnum and .45-70. In this video I discuss the methods of conversion and decide which is the better option.
The Mauser 1871 fires a cartridge known as the 11mm, or 43 Mauser. It's a large bore black powder cartridge that unfortunately is very hard to acquire the brass for today. I previously tested if 45-70 or 300 Win Mag cases can be converted to work as 11mm Mauser. The best solution at the time was 45-70 with an O ring added to the rim so it can properly headspace. The 300 Win Mag conversions were functional, but ultimately they required too much work to be converted and their reloadability was in question. However, I stumbled upon an article online that shows hwo to swage a rim onto a rimless cartridge. Since the 300 Win Mag is technically rimless, I revisit it as a conversion posibility, abandoning any idea of doing it simply, in order to make the best brass I can.

Dave Cushman's website
http://www.dave-cushman.net/shot/44-06_rimmed_douglas.html

DISCLAIMER
All subjects featured on this channel are shown for historical and informational purposes only. All gunsmithing work is intended to restore the item to it's original condition, never modifying to serve any other purpose. In no way, shape or form is anything featured on this channel ever intended to be sold at any time. Any messages regarding selling a firearm, ammunition or an accessory will be removed. Everything shown is legal where the creator is located, please check your local laws.

00:00 Intro
01:30 Rimming the rimless
03:50 Prepping the case
06:48 Making the ring
11:46 Using the swaging dies
14:11 Hydraulic pressing
17:23 Results
18:29 Machining the rim
21:45 Test resize
23:49 Oversized rim
25:31 Shooting
26:44 Conclusion