Trail Boss strangeness

[Sam1911]

I had an odd discovery today.

When I'm in a revolver-shooting mood, I tend to put a lot of .44 Spcs. through my 629, and my pet load is about 6.7 gr. of Trail Boss under a 200 gr. LRN-FP. That gets me right to 850 fps, which is high enough for me to shoot either revolver class in IDPA.

But rather than stick with a good thing, I decided to do a minimum load batch to take advantage of IDPA's new very low power floor rule.

Trail Boss is listed with a starting load of 4.3 gr. in .44 Spc. with a 200 gr. slug, so that's what I loaded. When I chrono'd a bunch of them this afternoon, I had really DISMAL results.

An average group of six rounds would clock anywhere from almost 650 fps to below 400! I had extreme spreads over 100 fps. This is by far the worst load I've ever come up with!

It's bad enough that I really was questioning whether something was wrong with my chronograph and I might go back on a day with less direct sun to see if I get the same results.

I'd have thought that a powder dedicated to the SASS guys making cowboy-fart loads would be polite at lighter charges. Anyone else see something like this happen?

 

[SPW1]

Most powders will have a certain pressure or density they perform best at. It is rare to find a powder that will burn consistently and have a low standard deviation across a significant range of loadings. I like trail boss for light loads in the 44 special, but I usually load around 6 grains or so and never had any desire to go lighter than that. My guess is the load simply does not produce enough pressure to be reliable.

 

[Sam1911]

That's a thought that crossed my mind, and if I was playing with H110 or something I'd have said, "of course!" I think I was just expecting more flexibility from a "cowboy" powder.

How DO those guys get those "sound-of-one-mouse-coughing" loads?

 

[SPW1]

That's a thought that crossed my mind, and if I was playing with H110 or something I'd have said, "of course!" I think I was just expecting more flexibility from a "cowboy" powder.

I learned a long time ago trying to make just about any powder to "flexible" usually comes at a the cost of poor accuracy, poor SD, dirty burning, or unpredictable pressures. Now I don't usually try to use the same powder to get a wide range of velocities. I find out where the powder does best and use it for that. Most of the time powders perform best near the maximum working pressure they were designed for. Sometimes you will find exceptions, but not often. The nice thing about trail boss is near "maximum" loads for it that give the best groups, lowest SD, and cleanest burning are still relatively mild loads.

How DO those guys get those "sound-of-one-mouse-coughing" loads?

One thing to remember is that they don't need great accuracy to hit large steel plates at close range. A lot of the real "mouse cough" loads they use will have terrible accuracy and poor SD, but for their application it doesn't usually matter that much. If they want a little better performance because they aren't happy with the sort of load performance your getting they just increase the charge a bit till they reach a consistency level they can live with. The weakest loads have to be just right to work well and that can include fiddling with hotter primers to try to bump the pressure, softening the brass so it expands easier, and probably other tricks too. From my point of view it isn't worth it to try to push the envelop to get the weakest load possible just like it isn't worth it to push the envelop trying to get the most powerful load possible.

 

[Waywatcher]

The nice thing about trail boss is near "maximum" loads for it that give the best groups, lowest SD, and cleanest burning are still relatively mild loads.

This has been my experience as well.

I'm really glad the OP brought up the new SSR Power factor. That was news to me, and good news at that!

 

[Sam1911]

I'm really glad the OP brought up the new SSR Power factor. That was news to me, and good news at that!

Good news? Bah! Just makes it that much harder to be "competative" with a 200 gr. bullet load!

I think I calculated that if I switch to some of the 300 gr. slugs on my reloading bench I only have to break 350 fps now.

I think maybe I'll stick with what's worked so far up at the top end of the range.

Thanks guys!

 

[Lost Sheep]

Try this

Load up some more of the same charges and when you run them over your chronograph try this:

Point the gun straight up and then lower the muzzle to level and fire a round over the chronograph (keeping the powder near the primer end of the cartridge). Do this several times and observe the average velocity and distribution of deviations.

Point the gun straight down and then raise the muzzle to level and fire a round over the chronograph (keeping the powder near the bullet end of the cartridge). Do this several times and observe the average velocity and distribution of deviations.

Report your results back to this thread.

When my shooting buddy did this with some 800 fps 300 grain 500 Smith & Wesson Magnum loadings of Trail Boss, we found a significant and reliable velocity difference in the averages, but a fairly tight distribution around the two clusters.

Lost Sheep

 

[Sam1911]

I thought of that, and I may try it, but it doesn't reflect very well the kind of shooting I'll be doing with these rounds. IDPA being fast-paced and shot from all kinds of angles and positions, I'll have to count on the luck of the draw as to where the powder will be in the case when the primer fires.

 

[PO2Hammer]

Are you weighing the charges or metering?
Trail Boss will meter like a champ one day, and poorly the next.
I've never gotten good SD figures with Trail Boss even when weighing charges in revolver cartridges, but the accuracy is usually pretty good.
IME, Titegroup works better for mouse fart loads despite the very low loading density in revolver cases, and gives better SD figures.

 

[Sam1911]

Ha! I'd given up on Titegroup long ago because of that exact issue. When I discoved I could charge the case 5 times before it overflowed (thus, I could have charged it at least tripple without catching it visually) I decided to go with something bulkier for the "huge" .44 Spc. cases.

I throw all these charges with the Dillon powder meter on the press. It's intended to be good enough for my uses. If not, I'll change powders before I hand weigh X,000 rounds a year!

Thanks!

 

[Waywatcher]

Trail Boss will meter like a champ one day, and poorly the next.

I have only loaded & fired about 3000 rounds with Trail Boss, but my experience with metering has only been a "Champ." In .38 special I get 4.0 to 4.2 grains max spread. The majority are 4.1 to 4.2. I measure the first 10 and then every tenth one after that, per reloading session.

I use a RCBS Uniflow with the small cylinder. What do you use?

 

[buck460XVR]

I've been told that since Trail Boss was designed to replace black powder, it works best when used @ 80% to 100% of case capacity, without compressing. This has been my experience also, so poor results from light loadings of it does not surprise me. I've always used IMR's recipe of 70% of case capacity as a starting load. Altho it throws worse than Unique for me outta my Uniflow, it still produces good enough accuracy for the application intended, even with the wide SDs.

 

[Sam1911]

it works best when used @ 80% to 100% of case capacity, without compressing.

Yeah, that's probably where I'm having trouble. Actually, my normal load is very slightly compressed, I think, but it works very well. Probably shouldn't have expected to get good results down low, but it was worth a try!

Sure was a soft-shooting load. --<sniff>--

 

[Lost Sheep]

How about using filler?

Yeah, that's probably where I'm having trouble. Actually, my normal load is very slightly compressed, I think, but it works very well. Probably shouldn't have expected to get good results down low, but it was worth a try!

Sure was a soft-shooting load. --<sniff>--

I thought of that, and I may try it, but it doesn't reflect very well the kind of shooting I'll be doing with these rounds. IDPA being fast-paced and shot from all kinds of angles and positions, I'll have to count on the luck of the draw as to where the powder will be in the case when the primer fires.

To keep the charge near the primer, charge the case, put a cardboard wad over the powder, fill the rest of the case with filler (fiberfill, kapok, or the old standby, cornmeal, or grits)

Good Luck. Never give up, never surrender.

Lost Sheep

 

[Sam1911]

Yeah, that's not a bad idea. I don't know how to make it work on a progressive press, but it would be a cool experiment.

 

[Sam1911]

Oh, and from more tinkering today, I don't really get as good metering as I'd remembered, which probably doesn't help. I'll run some of my 6.7 gr. loads over the chrono soon and see what I'm really getting from my old standby load.

 

[PO2Hammer]

To keep the charge near the primer, charge the case, put a cardboard wad over the powder, fill the rest of the case with filler (fiberfill, kapok, or the old standby, cornmeal, or grits)

From everything I've read, pushing the wad down to the powder is not a good idea.
Paco Kelly warned of ringing the chamber that way, others point to the possibility of the wad tipping and getting mixed in with the powder. Unlikely maybe with Trail Boss and filler, but wads work great tight up against the bullet base, so why risk it.
I like the thick (.060") Walthers vegetable fiber wads from Midway. They seem to reduce smoke as well.

 

[Sam1911]

Update:

I bumped the load up to 5.0 gr. and tested yesterday.

I re-checked my 4.3 gr. load over the chrony and got one 6-shot group with an extreme spread of 209 fps.!

Then checked my standard 6.7 gr. load and found much better consistency. (Usually about 30 fps ES.)

Then checked my 5.0 load and was shocked to find the ES drop down in the 10-20 range!

Velocity very steady at just over 700 fps. That will do just fine! Not quite down at the 530 I'm allowed, but steady and easy shooting.

Guess I found my new favorite load!

 

[Walkalong]

With many pistol powders the ES will be big until it hits a certain velocity/pressure/% of the case filled/and/or a combo of all three. Seems to be different for nearly every combination.

Trail Boss does not work well if the charge is really small, and it doesn't like plated bullets. It is also erratic if compressed too much.

 

[Sam1911]

I've never tried it with plated or jacketed bullets, but I believe my top end load (pushing 850 for IDPA ESR Division) is a little compressed. Still works, but obviously it REALLY likes the lighter charge.

Neat discovery, and thanks to all for the advice!