Heavy load revolver help

[Cowboy_Dan]

I have a Thunder Five revolver by Mil Inc. The company doesn't exist anymore so I can't ask them about this, but I bet someone on this forum can shed some light on this. It's a five shot revolver that came in .45 Colt/.410 3" shotshell or .45-70. It seems in an effort to keep costs down they used the same parts for both models, the only difference being the stamp on the barrel and the reamer used on the cylinder. As such, my groove diameter is .458"-ish.

So, in an effort to not have keyhole groups, I have setteled on using light for caliber .45-70 boolits. The problem is, the only data I can find for boolits that large is in the Ruger Backhawk/ Thompson Contender only section (specifically loads designed by John Linebaugh). I have no fear that they are too hot for its Ruger-style action. However, their recoil does cause one problem.

For some unknown reason, this revolver was designed with a thumb safety. It is a switch-actuated rolling bar which stops the hammer short of the transfer bar. When I fire start loads through it, the recoil moves the safety from here:

110293
To here:

110294
Which interferes with cylinder timing.

First, I tried simply removing the safety, but I was uncomfortable with how much travel the transfer bar was allowed. Maybe it isn't a problem? I wasn't sure. Then I got a "genius" idea to reverse the entire safety assembly in the frame so thatbfire was down and the switch wouldbhave nowhere to travel. This was definately a problem. The bar of the safety has a slot cut into it for the transfer bar, which invaribly caught on it in dry fire tests.

So, does anyone have any other ideas? Or is there any problems in the reasoning above? Is it OK to allow a transfer bar to flap while the hammer is drawn? Oh, and here is a picture of the whole thing for anyone who is interested.
110295

[Cowboy_Dan]

I should mention the data I fired:
330-ish gr Gould Express RNHP boolit cast by a friend sized .459"
21.0 +/-.2 gr Win 296
Sellier & Belloit LP primer
Mixed headstamp cases, unknown # of firings (I hadn't kept track using standard pressure loads, but about 3rd loading).

[dubber123]

I would have to assume the safety "clicks" into the on or off position, and if that is the case, I'm sure it has a spring loaded detent of some sort that is supposed to keep it on place. Find the spring and try upping the spring pressure, or if the detent "divot" is very shallow, try deepening it carefully. The idea being to make it harder to activate the safety. You might try moving this thread to the gunsmithing section if you don't get any more ideas in a few days. Good luck.

[lar45]

That looks like a very fun revolver!
I like Dubber's suggestions to make your saftey switch harder to accidentally move out of position.
So I'm assuming that yours is the 45/410 model? Is there enough room in the cylinder to safely chamber the 458" bullets loaded into 45 Colt cases and still have enough room for the case to expand and let the bullet go?
Are you looking for lighter load data for your 300-350gn bullets? If so, post or PM me your bullet length and loaded length along with which powders you have and I can run it through Quickload to get an idea of starting powder charges.

[Cowboy_Dan]

Lar, that wasn't exactly what I was looking for, but whatever works. The boolits seem to have space to leave the case, 5 have done so already. I stopped after 5 shots because I was tired of resetting the safety for every shot. Just did a measurement, loaded round is .478 at the neck, fired is .480 (cylinder dia.).

I am trying to not do anything to the gun which will affect its historical value (if indeed it has any). Dubber's idea may work, I'll have to look closely at the gun. EDIT: safety does not appear to have a divot and spring mechanism but does have some sort of stop. It does not really click.

Boolits are .912
Loaded round (one chosen at random) 1.769, but I could seat further out, I have 3" of chamber.
I have AA#7, Win 296, and IMR PB on hand, but could pick up another powder if need be.

[Jupiter7]

Neat gun, started the big craze leading to the Taurus judge and S&w governor. I have a hunch you'll get best results out of a lighter boolit and normal pistol powders. Don't believe that h110 will do you any good with this pistol.

[I'll Make Mine]

One option would be to lap a mold that throws reasonable weight boolits -- say, 230-240 grain -- to the diameter you need, though that won't necessarily help your recoil problem. Another would be to either modify the existing safety bar so it doesn't interfere with the transfer bar, make a non-rotating pin to replace the safety and retain the transfer bar (i.e. same thing without the external toggle), or make a new safety that works correctly in your preferred orientation. My preference would be to replace the safety with a suitable pin (IMO, a revolver with transfer bar needs a thumb safety like a fish needs a bicycle). Either of the latter two options would allow replacing the original, poorly designed safety, i.e. wouldn't be permanent modifications, hence preserve the historical value of the revolver, as long as you can avoid losing the original safety.

[Cowboy_Dan]

Thanks for the further replies. I think lighter boolits would be the best solution. I don't think I would be too sure of myself lapping a mould just yet. So, unless I can find some even-lighter for caliber .45 rifle boolits (or such a mould), I would be leaning towards fabricating a transfer bar retaning pin to replace the unneeded safety. Barring a better suggestion.

As far as the pin goes, since it isn't structural, I bet it could be made of wood. Just cut it to shape out of dowell and good to go, right?

[DanWalker]

The Mihec Hammer boolit sounds like just the ticket for this gun. I size them to .454 and shoot them in my blackhawk, loaded over 6.5 grains of red dot for a punchy load without a lot of recoil, blast, or pressure.

[Cowboy_Dan]

What does it drop at? My 45-70 compatable barrel needs about .459.

[DanWalker]

What does it drop at? My 45-70 compatable barrel needs about .459.
Mine drops at .460

[NVScouter]

Dan's sugestion is good as is the LEE 340g for 45-70 with a lap job. OR get Accurate to cut you a 280-300 .461 mold. But be careful I'd check the cylinder throats (if any) forcing cone and barrel sizes before ordering a mold.

Why not expoxy the safety in place? Worst case it has to be disassembled and the epoxy removed.

[Cowboy_Dan]

That may also work, NVScouter. What epoxy would you recomend? I would think the J-B Weld I have on hand would damage the bluing if I were to try to remove it.

So solutions to try so far:

Lighter Boolits
Fabricate a transfer bar retaining pin to replace the safety
Epoxy the safety in place

Any others?