I Come Seeking Guidance and Knowledge: Trail Boss 45 Auto Rim

[challenger_i]

I am getting ready to load target rounds for my 1858 Remington w/Taylor cartridge conversion cylinder.
I will be using 45 Cowboy Special brass, so as to keep my "1858-specific" ammo separate.

As many are aware, finding load data for Trail Boss can be "challenging".

I have used TB in the past, for various BP cartridges, so I am familiar with the powder.

I can find data for 45 ACP, no problem. However, when comparing published data for 45 ACP and 45 Auto Rim,
in standard smokeless loads, there is a startling difference between the two. I do realize the cylinder gap plays a decided
part in the pressures observed (when One can find pressure data associated with powder charge/bullet data).

There is nothing published about "pressure" limitations for the Taylor cylinder, just "velocity" limitations (850fps).
However, as the cylinder chamber walls are rather thin, I would prefer to not tickle the pressure tiger.

My issue is this: the published 45 ACP/Trail Boss loads, in the 750-800fps range, show pressures in the 15,000 to 16,000psi neighborhood. Again, these are derived in a "closed breech" system, not a revolver.

I would enjoy further input.

[Winger Ed.]

My understanding was the .45Auto rim was toned down so people wouldn't get in trouble
using the ACP data in older revolvers like a WWI and maybe WWII Webleys.
They could shoot .45 ACPs, but it's real hard on them.

Do your own research, this is just a vicious rumor.

[challenger_i]

Ah! See, THIS is the reason I cast this subject out there!
I am aware of the tales about the dangers of shooting 45 ACP in a 1917, be it Colt, or a Smith. The Webley tales are well founded, as the MkV and MkVI were marked at Birth as to their pressure rating.

For a comparison to "Cowboy" loads, which the Taylor paperwork does recommend: Magtech 45 Colt Cowboy (250gr) ammo is marked on the box as generating 750fps. It would be helpful to know a pressure rating for that load, so as to assist in figuring out a comparable Trail Boss load for the 45 CS.
As they say, the Devil is in the details.

[rintinglen]

recoil is directly related to velocity. (Which is related to pressure.) My guess is that by suggesting a velocity limit, Taylor seeks to limit both recoil and pressure. Were it I, I'd start at Hodgdon's starting 200 grain load, 3.5 grains, and ladder up to 4.5 grains, well below the 16,000 CUP that their upper load runs at and accept whatever pressure that gives me. Given that these are target loads, "enough is enough." You'll only need enough oomph to pierce the target, not a Grizzly Bear. The fly in the ointment may be sight regulation.

My 1860 conversion doesn't shoot to point of aim, though it is close enough for popping a Half-size cowboy metal target.
I use an old Lyman 456-401 which is roughly 190 grains.

[challenger_i]

Thank you, sir. My 1858 has performed admirably with the Magtech and my light load 45 Colt hand loads. Is amusing that, with C&B or cartridges, my 1858 is the most accurate sidearm I have ever pointed at a target!

[lar45]

[challenger_i]

Yes sir, I have that flagged. What I am looking for is "Real World" user information.

[rintinglen]

FYI, I use ww-231 in my Schofield loads, using the starting load for a 200 grain boolit.

[challenger_i]

Originally, I was intending on 45 S&W for my stand-alone cartridge for the 1858 but was disheartened when I discovered it would not fit my Colt New Service in 45 Colt. Wishing I had continued down that path.

[45 Dragoon]

Pressure data doesn't include bc gap. That varies from revolver to revolver. Chamber pressure is CHAMBER pressure. The bullet moving forward is the pressure "relief" until the gap is crossed and then it still continues diminishing for the length of the barrel. The .45 cal column of relief is your best friend for dumping pressure . . . more so than .429" or .357" or anything smaller.
The main reason the cylinder manufacturers use velocity rather than pressure is it's easier to understand. Nobody makes an "off the shelf " round in 45C with 250gr bullet at 1000fps that is more than 14K psi. The term "cowboy load" means nothing. Your cylinder is the "limiting" factor so find a load within tier 1 pressure that your revolver likes and you're done.

Mike

[murf205]

Well, my info is not Trail Boss but my 625-3 does 790 fps with Accurate # and a 253 gr boolit. I never had it pressure tested but of course my gun is different from yours. That is 1 neat pistola you have there.

[Tall]

I've been looking for Trail Boss for years. According to my local gun store it was discontinued many years ago. I have never seen any available.