Hey guys quick update on this project.
I finally got to load some 10mm mag ammo for this little beast
180 grain hornady xtp over 21 grains of h110
Yields one group of under an inch at@ 14 yards
Hope to get the chrono out on it soon
So far very happy with the results.
More data to follow .
Thank you all for the info and the brass.

I was wondering how you were coming with your project.

I waited 4 months for my reamer and they shipped me a 10mm Auto instead so I waited another month for the correct one.  In the meantime, my Gunsmith took another job and I have not been able to find anyone local to rechamber it yet.

I hope you do better than I am.   

Yeah it's been a bear to try and get this project rolling .
I also picked up some 41 mag brass reformed into 401 powermag
I will try and trim those down to the right length. And load them for
The 10mm mag.
So far I'm very happy though.

I like the idea but how much 10mm mag can a gp handle?

Related thread for rimmed.

https://www.10mm-firearms.com/general-discussion/10mm-rimmed-case/

Did my full write-up here

http://smith-wessonforum.com/s-w-revolvers-1980-present/647533-making-10mm-rimmed-brass-use-610-a.html#post141118897

I've been working at the school as a teacher for many years now, and it's important to me that the kids graduate with some sort of military knowledge base. To do this, I show them weapons and ammunition live. A month ago, I ordered 10mm revolver ammunition so the kids would understand the drill. Next week I'm going to show them the Remington 700 rifle; I've already ordered the missing ammo, such as rings, from https://ballachy.com/best-scope-rings-for-remington-700/. Specifically, Vortex Optics Pro series scope rings.

Wish I could post photos . Took a nice boar javelina @90 yards with the 10mm mag revolver. With the 21 gr h110 over the 180 xtp.
Pretty happy with the project so far. 😊

Quote from: hollywood63 on October 24 2021 04:24:24 PM MDT
I like the idea but how much 10mm mag can a gp handle?

When the GP 10mm first came out, someone posted on the Ruger forums that Dave Clements refused to
do the conversion, saying the gun would shoot itself apart.

When it comes to big-bore magnums, I go with the single actions.  Much easier on the hand.

@Troutramp - have you tried any heavier loads yet? I was debating with myself about bumping my Match champion up to 10mag, but when I shoot the Doubletap 230gr load (1120 fps) the empties stick and require a good rap on the ejector. When I measure the bases, the unfired rounds are .420, while the empties are .428-.430. That has discouraged me from wanting anything hotter in that revolver. As it is, I'm thinking that I will not be reloading that brass. Then again - maybe the larger case would give lower pressures for a comparable load?