Some of you may be aware of my wildcat developed for the 1895 Marlin. It is based on the 7.62x54R case and shoots 300 grain bullets made for the .405 Winchester.

I immediately recognized the utility of such a rimmed cartridge for use in the Mosin-Nagant and Siamese Mauser. So, I decided to move in that direction, working first with the Mosin. After all, the .405 Grenadier is based on the very same 7.62x54R cartridge the Mosin-Nagant was designed for.

I acquired a proper rifle for the build and began to gather what I needed for the conversion. Then my attentions turned elsewhere and the .405 Grenadier Mosin-Nagant project was put on hold.

Here is my last post on it:

After sitting idle for too long, I have moved fast forward on this project. The above photos should now be labeled "BEFORE".

At this moment, the rifle is with Tom Jackson of Davenport, Iowa. I sent him a new bolt handle, sights, and some dummy rounds topped with various bullets by Swift, Hornady, Hawk, and Woodleigh in weights of 350gr and 400gr. The bullets were seated on the cannelure, and overall lengths were all well below 2.9" with room to spare.

Tom installed the items and rebarreled the rifle with a McGowen .405 barrel I had sent his way. Most importantly, Tom opened the magazine to accommodate the fatter cartridges.

I should have the rifle back in a few weeks, after bluing. But for a teaser Tom sent me this video showing how it feeds everything he throws at it. These are four dummies topped with a mixture of different bullets and weights.

http://vid712.photobucket.com/albums/ww1...zpsqkfwrxzn.mp4

Now it's getting interesting. Expect an update on this very soon. I already have some loads I am just dying to try out.

FWIW - A .405 Winchester with a 400 grain bullet loaded to standard overall length has a usable case capacity of about 52 grains of water. The .405 Grenadier with a 400 grain bullet loaded to 3.0" overall length, cannelure 1/4" beyond the mouth, has a usable case capacity of just over 53 grains of water. Yes, with heavy bullets loaded out the Grenadier holds the same, or even a bit more, powder than the .405 Winchester.