Bought a bottle of Trail Boss today Data looks strange HELP!

[Master Blaster]

Well the title says it all I went to the IMR website and looked at the trail boss data for .357 mag and .38 spl in the 158 LSWC bullet style. The load is listed for both cartridges and they both have about the same velocity 800-865 fps. OK its cowboy data and probably not really maximum. BUT
for the .38 spl 158 LSWC they list a max load of 4.2 gr, pressure 13,700 CUP, of Trail Boss.

For the .357 mag case they have 4.2 gr of TrailBoss and they list the pressure as 20,700 CUP

Problem the .357 mag has a larger case and it has a 7,000 CUP INCREASE over a smaller case with the same bullet and the same 4.2 gr load???????

Is the .38spl load SAFE Would it be safe if the real .38spl pressure is like 23,000 CUP?????????


Data is here http://www.imrpowder.com/data/handgun/trailboss-feb2005.php

 

[Oldnamvet]

I just looked at the new IMR booklet and you are right about what they are publishing. Could the standard vs. magnum primer have made that much difference ? Or did they make a typo on the maximum grains since the starting loads for the .357 are higher than for the .38 Spl? Looking at the difference between .44 Spl and .44 mag there is about the same type difference in pressures BUT the maximum loads are also higher so it makes sense here. I would bet that they just copied over the max loads for .38 by accident into the .357 data table.

 

[P95Carry]

If there does prove to be any inconsistency of note - it'd be worth posting that info in the sticky thread about powder recalls -

http://www.thehighroad.org/showthread.php?t=47578

Where I think it could still be useful ref' material.

 

[Master Blaster]

I see the magnum primer for the .357 mag load but that seems a bit odd as well, because trailboss is a fast burning powder like bullseye. Could the primer make a 7,000+ CUP difference in a slightly larger case?????

 

[Slip Shooter]

Flags up

I purchased two bottles of Trail Boss for use with practice loads with 158gr Rainier HP's.

The published data by IMR is confusing and seems as if the data for 38 Special and 357 may be reversed. My original thoughts were that I could probably increase the 38 Special data by 10 per cent and get good velocity out of a S&W M642 and M14. Now I am leery of the data. The 4.2 38 Special charge may be over 20,000 psi in the +P range, or more!

I haven't had an opportunity to actually load and test Trail Boss. I will be doing that later this summer.

Anyone out there got personal data on the 38 Special and 357 Trail Boss loads.

 

[BluesBear]

Interestingly enough, the August 2005 issue of Handloader magazine has an article on pressure signs.

In their testing they tried six different primers ithe the same bullet and powder charge. Now I realize that they were using a 7mm Remington Magnum and that this thread is dealing with handgun loads.

However, it's still interesting to note that with six different primers they only saw a difference of 21fps in average muzzle velocity while at the same time they experienced a difference of 12,800 psi in average chamber pressures.

The loading manuals have been warning us for years that changing components can have a significant effect.

This article also ilustrates how easy it is to get into areas of marginal safety with no readily visible warning signs. Higher velocities aren't always a reliable sign of higher pressures.

Just another reason that I have always compared loads in one manual against loads in another. Typos are always easy to make and sometimes difficult to notice. Thankfully I have always been a better reloader than typist.
I always wait until there's a little more published data available before using a new powder. I firgure I'll let somebody else do the research and dig up the unpublished features. Until they perfect the regeneration of body parts I'll just try my best to keep the ones I already have.

 

[saands]

In their testing they tried six different primers ithe the same bullet and powder charge. Now I realize that they were using a 7mm Remington Magnum and that this thread is dealing with handgun loads.

Were these ALL the same type of primer? For example all magnum or all non-magnum? That sounds like an article I'd like to read. It seems odd that a powder's burn profile could be so dramiatically altered, but hey, if they did a valid test and got valid data, then I have to go reread the back of a one dollar bill and remind myself what it says: "In God we trust" ... the mint left off the second part ... "All others must bring data!"

Is this issue still on the stands?

Thanks,
Saands

 

[Al Norris]

The current issue of Handloader, August 2005 (No. 236), came out on the stands last week. The article is on page 62, "Velocity and Pressure" by Johm Barsness.

 

[Master Blaster]

The 7mm mag data effect is interesting but its a rifle cartridge and probably has either no space in the case or is a compressed powder charge. So I would expect small changes like a magnum primer or an extra grain of propellent could create big increases in pressure.

The pistol loads we are talking about are not compressed or filled to case capacity.


I will call them today and ask about this anomaly with .357 mag and .38spl.

Well I called them and they said the data is correct and safe. The 7500 cup difference is because of the magnum primer.

How many folks here use a magnum primer with a small charge of fast burning powder?????

 

[BluesBear]

The real question is; How many people would think that the primer switch would make such a big difference in pressures?

There are many reloaders who think that just because the case says magnum that you should always use a magnum primer. Oh yes there are. I have talked face to face with several such misguided people.

Yet another reason to not shoot someone elses reloads.

I have alse met people who feel that it doesn't make any difference if you switch primers. "A primer is a primer ain't it?"
Those same people usually are of the mistaken mindset that all XXXgr bullets are the same. "You can just use whatever bullets the shop had in stock right?"

Did I mention that I don't shoot other people reloads in my guns?

 

[roo_ster]

Yet another reason I am glad I use 2400 for my heavy .357 loads: no magnum primer called for.