Mini Trail Boss review: 357 Magnum


Peter M. Eick
December 28, 2005, 08:11 PM
CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

I shot some trail boss test today with my Python. Here is an example of the results:

This is 50 shots, offhand, 15 yards.

The load is an OVERLOAD of new starline brass, cci-550 primers, 158 grn Lasercasts SWC and 4.4 grns of Trailboss loaded to 1.590 COL. Let me be BLUNT. The max book load is 4.2 grns with the same parameters so I am not advocating this load for your guns. This just worked well in my gun.

My thoughts are that this load is still very mild. Just about a 38 special load in the gun. I did not chrono it (the range was still a zoo with newbies). It was much more mild then 4.5 grns of Titegroup which was my previous plinking load.

The gun was very very clean. Trailboss burns with a weird smell, but it is very very clean. It put titegroup to shame in this respect! The Python is a bit dirty because of the 300 rnds of 14 grns of 2400 I blasted afterwords, so don't judge the gun by the dirt.

Although I think the load was accurate, it is just to mild for my desires. In my guns I will up the load slowly till I can equal my 4.5 grns of titegroup in accuracy and general recoil. I have my guesses as to how much of an overload that will take, but I will not post that number here. It will require some serious pressure ring measurements and chrono mapping to figure it out.

By the way, a double charge of 4.2 grns spills out of a 357 mag case and is nearly perfect for my safety requirements. I can handle a squib load from no powder since I am a target shooter, but I am very careful about double charges when I am not using a lock-out die. In my Pro-2000 I swapped the lock-out die for a Redding Profile crimper if the load will spill on a double charge. If it will not then we are back to the lock-out die.

So my summary:
1) Great powder
2) Accurate
3) Weird Smell
4) Existing load data is very very mild (noticed this also with my 38 special experiments).
5) It has become my standard revolver powder for target loads. Now I just have to use up the titegroup, 231, Bullseye and AA2 Improved!

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Jim Watson
December 28, 2005, 08:33 PM
I read earlier today - can't find now, maybe it was too explicit and was deleted under new SASS policy banning load data - that the limit on Trail Boss loads was that it would not tolerate compression. Reportedly, much of its burn rate control is dependent on granule ("Cheerio") shape, and if you distort many of them, it gets erratic. But there are people loading autopistol cartridges with TB which usually requires compressed loads for function, and they haven't had any trouble... yet.

Peter M. Eick
December 29, 2005, 08:19 AM
Interesting on both points. I did not know that SASS was not allowing load data anymore. I only rarely go there because it is so hard to find anything in the churn of threads.

It does make sense about not compressing Trailboss. In my 38's and 357's they are not even close to compression yet, so I will just not worry about it.

I am looking forward to burning out the rest of my fast powders in my 45acp so I can standardize on Trailboss for my Revolvers. The safety factor is great with the stuff.

No more "Titegroup squint". :) :) :)

December 31, 2005, 11:54 PM
As a relatively new reloader, the can of Trail Boss I bought has been a G-dsend.

I've loaded up .357mag plinker loads for my SW686 and .44mag plinker loads for my wife's 92 lever gun. I'm not going to risk a double charge of Bullseye in a plinker load for my wife. Just ain't gonna happen.

With 2400 for hot loads, I'm one happy revolver reloader.

I would really like blessed load data for other, non-CAS cartridges. While the maufacturer is at it, how 'bout some reduced rifle loads with TB?

The Bushmaster
January 1, 2006, 12:07 PM
Peter...Have any idea what it does over a chronograph?

Peter M. Eick
January 1, 2006, 03:05 PM
The public range I go to is a zoo after christmas with all of the newbies with the new guns from christmas. I would not risk my chrono to them and I try to avoid it myself to avoid getting shot by some idiiot. I pity the RO's dealing with the newbies who don't know basic gun safety.

My guess is the round would chrono right at 800 fps though. I would prefer about 1000 fps with Lasercast bullets. They seem to do pretty well at that velocity. Hence the reason I am uploading slightly.

I will chrono them along with my ladder test this month and let you know.

The Bushmaster
January 1, 2006, 04:27 PM

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