Trail Boss in .357 Mag

[Black Jaque Janaviac]

Trail Boss lists a max load for .357 which is about the same as for .38 spl and is fairly low velocity. I believe those loads are what TB considers "Cowboy Action" loads, or smokeless loads that produce equivalent black powder velocities for cowboy action competition.

For cartridges that do not have a listed recipe for TB, they recommend following this procedure:

Listed below we show a few examples of such loads throughout the Reloading Data Center, but the fun doesn't stop there. If you
don't see Trail Boss data for your favorite cartridge we have a formula for developing loads for all cartridges and it's simple to
follow. This formula may be used in both rifle and pistol applications:
Find where the base of the bullet to be loaded is located in the case and make a mark on the outside of the case at
this location. Then fill the case to that mark with Trail Boss, pour into the scale pan and weigh. This is your
maximum load. Pressures will be below the maximum allowed for this cartridge and perfectly safe to use!
Take 70% of this powder charge weight (multiply the maximum load from step 1 by .7), and that is your starting
load.
Start with this beginning load and work up to your maximum charge, all the while searching for the most accurate
reduced load. Once found, the fun begins!

So, is it crazy to stray from the TB .357 published recipes and follow the process listed above?

[Chainsaw.]

Nope. I’ve done it several times. This is the ONLY powder I would recommend this with though.

[Tripplebeards]

I just did the measure thing myself from the base of the boolit. Big variance compaired to published loads. The published START loads crushed powder for me in 44 mag. I had a 400 FPS variance through my chrony with crushed powder.

Here’s my post

http://castboolits.gunloads.com/showthread.php?376310-Loading-44-mag-with-trail-boss-what-am-I-missing

[44Blam]

With this powder DO NOT compress a load. Just load to the bottom of the boolit and that's it.

[Black Jaque Janaviac]

The published START loads crushed powder for me in 44 mag
Really? According to the Make-your-own-recipe you don't exceed 100% load density.

[SvenLindquist]

There is a free book available with TB cowboy action loads for TB.

[Black Jaque Janaviac]

cowboy action loads for TB.

But I don't know if I want cowboy loads. I am pretty sure that cowboy loads are based on a velocity limit that competitors have to be under in order to participate in CAS events. So I suspect that for, say .357 mag, TB could go as high as 100% load density without exceeding max pressure. I'm just checking here to see if my thinking is correct.

Although one guy here is saying that published loads of TB exceed .44 mag 100% load densities - so maybe those CAS loads are based on maximum safe pressures?

[tsubaki]

If you have some loads you are already using with Trail Boss go back to Hodgdons site and recheck your data.
They recently changed some of their data using Trail Boss.

[JoeJames]

Nope. I’ve done it several times. This is the ONLY powder I would recommend this with though.No kidding. I ain't even going to speculate on the results you would get with any other powder, and sure ain't even going to mention the name of any other powder - shudder - shudder.

[reddog81]

100% load density in a .357 magnum case will still feel like a "cowboy load".

[Tripplebeards]

Really? According to the Make-your-own-recipe you don't exceed 100% load density.

That’s why I suggested to make your own recipe instead of using book recipes. It all depends on your boolit and seating depth. The problem I ran into is most bullet/boolits are different measurements. If you load to the same aol with various longer and shorter boolits they are going to be at different seating depths that poses a problem. Your better off to mark to the side of your case where your boolit will be seated, fill to the line with powder which is your max load and start with 70 percent less to start. I minused .2 grains from my fill line just to make sure I didn’t crush the powder. It takes all of a few seconds to check and then you know your not crushing powder.

[Black Jaque Janaviac]

100% load density in a .357 magnum case will still feel like a "cowboy load".

That's fine. TB is not a magnum powder, I was just curious if I was limited to published data, when Hodgdon clearly gives excellent instructions for how to come up with your own max charge. And it appears that the DIY method may actually be better than published.

About the only other powders that come close to the simplicity of TB are black powder and its substitutes. Although with those you pretty much must go straight for the 100% load density.

[Harry O]

Follow the directions you posted. You can go quite a bit above published loadings that way.

I was doing some loading with a 45 Long Colt a few years ago using brand new Starline brass. I think the max. load published at the time was about 5.5gr. It did not even seal the cases in the chamber. They were all black on the front 1/3 of the case and the accuracy was poor. I kept increasing the TB a little bit at a time. It eventually sealed the cases and accuracy got better. I took it all the way up to a full case without compressing the powder. It was about 9.0 or 9.5gr. I have no way to tell what the pressure of the load was, but the felt recoil was less than some of my Unique loads so I believe they are not a long term problem.

I also load 44-40 and 38-40's with Trail Boss. The brass for them is so thin that 5.0 to 5.5gr of TB will seal the cases and give good accuracy. I would think that .357 Mag cases are heavy enough that they would need more than minimum TB loads to seal them.

[DaveTNC]

There is a free book available with TB cowboy action loads for TB.

I haven’t found this book. Do you have a link to somewhere to get it from?

Thanks

[Dieselhorses]

I've read that it depends on what gun you have and that there are the basic old light loads, medium loads and "Ruger only" loads. Also like Tripplebeards mentioned-depends on seating depth, bullet style etc. Lyman 4th has useful info concerning this powder.

[eric123]

http://www.hodgdonreloading.com/data/pistol

Can't find link to pdf, but this works

[Mitch]

http://www.hodgdonreloading.com/data/pistol

Can't find link to pdf, but this worksit is on hogdon.com strangely the links are not on the reloading data site.
https://www.hodgdon.com/resources/data-sheets/

[sniper]

I decided to try something. I got a .357 case, measured and marked to the base of a 158 gr SWC boolit, which I figured would be the longest projectile I'd be likely to use, then used my Dremel to cut it off at the bottom edge of the line, to compensate for any error on my part. I filled the short case to the top with Trail boss, leveled it, then weighed the charge. 4.6 gr. :o The only max. load I can find anywhere was from a publication...4.1 gr for 357 Magnum and .38 Special. Just to double check, I went to the Hodgdon reloading data, and found that apparently, lately, Hodgdon has added a few loads to their data! sure don't remember seeing it there before! For shorter 125 gr. boolits...5.3gr. max; 158 gr.,4.2 gr. max. Right In the ballpark! I reduced my measured load .3gr to 4.3, and figured it would be a conservative max...not compressed, and no excess space. Sooo...now to work up carefully to and beyond the published max, and see if there may be a "good" load in there somewhere.:)

[Black Jaque Janaviac]

Here's a link to the page that I originally quoted:
https://www.hodgdon.com/wp-content/uploads/2018/12/trail-boss-reduced-loads-2018.pdf

[sniper]

Thanx; Seen it, got a copy in my files. Used it for my recent activities.:smile: