Trail Boss load results strangeness ...

[GBExpat]

While searching for an accurate "target/fun/kid's" load for GrandPop's old Colt Army Special .32-20 revolver, I noticed some interesting (to me, at least) results with Trail Boss powder.

I used the IMR load development instructions: 100% of available case volume is your maximum load and 70% should be used as the STARTING load.

I have found (with multiple different Test Strings) that the MV will, as expected, increase as you increase the load ... until ... shortly after you pass the 85% point (of available case volume).

At that point, the MV starts to decrease with each increase in load.

FYI & FWIW.

 

[Sunray]

You really need to look at a manual. Hodgdon shows 90 and 115 grain data for Trail Boss that's nowhere near "100% of available case volume". Start loads are 2.5 and 2.2 respectively.

 

[GBExpat]

You really need to look at a manual. Hodgdon shows 90 and 115 grain data for Trail Boss that's nowhere near "100% of available case volume". Start loads are 2.5 and 2.2 respectively.

I have looked at Hodgdon's "manual" as well as Hodgdon's load development instructions that I mentioned.

I used the IMR load development instructions: 100% of available case volume is your maximum load and 70% should be used as the STARTING load.

The source for both is Hodgdon. I chose to use the latter.

 

[Lost Sheep]

What do you mean by "100%"

Trail Boss should NOT EVER be compressed. If you take a case and fill it any more than where the base of the bullet eventually will be, you are definitely compressing it.

Take a pencil and hold it parallel to your bullet and put your fingernail right on the crimping groove. Then put the pencil point in your case up to your fingernail and mark (with the pencil point) on the inside of the case.

Fill to the mark with TB.

Weigh that powder. That is your 100% load.

Calculate 70% of that weight. There is your starting charge.

I assume you already did something like what I described, but I just want to be SURE and not assume anything.

Lost Sheep

 

[GBExpat]

Trail Boss should NOT EVER be compressed.

Yes, thanks, I am aware of that, Lost Sheep.

I used the IMR load development instructions: 100% of available case volume is your maximum load and 70% should be used as the STARTING load.

Funny thing is that I have yet to read anywhere the specifics of what occurs when you compress the stuff.

I must assume that a dangerous pressure-spike can result but, so far, I have found no official source that directly addresses the issue.

Perhaps their attorneys will not allow them to be completely open about it.

 

[Ccctennis]

There are various articles about compressing those doughnut shaped kernels changes the characteristics of the powder. Even trailboss says do not compress loads. The beauty of trailboss is how it fills a case due to its shape. Just have to be careful

 

[Clint M]

Reduced velocity with increased powder charge often indicates max or beyond max powder charge in a rifle cartridge. I have noticed this several times, and started a topic years ago when chronographs became cheap enough the average person could afford. You can research this as I have no idea how it relates to your case, however it I heard little bells ringing some where when I read your OP and thought about this information...hope it helps

 

[GooseGestapo]

Hodgdon Lil'Gun does the same thing. Several authors of "HANDLOADER" magazine articles have noted that exceeding Hodgdon's listed max loads results in a reduction of velocity. IE: 18.0gr of Lil'Gun under 158 JHP is max. 19.0gr is lightly compressed and yields ~75fps LESS velocity.
I've heard that compression changes granule geometry, altering burning rate. Whatever it is, it happens.

 

[GBExpat]

With the 100gr bullets I found the Velocity (and, thank goodness, also an Accuracy) Sweet Spot to be ~87% of Max.

Later this week when the drain field dries out I will test this with a 115gr String.

This last series, I tried a String of 115s loaded at the Max (4.0gr) and they produced an average velocity of 665fps.

I will load a String with 3.5gr (87% of 4.0gr) and see how it performs.

If my theory is correct, I will see an average velocity from this new 115s String in the upper 700s.

I will update this thread after I get that done.

 

[Walkalong]

What kind of bullet? I had very erratic and strange results with Trail Boss in .32-20 with a 100 Gr plated bullet.

4.1 Grs Trail Boss (About 99% Load Density) with a 100 Gr Ranier: PB = Powder Back PF = Powder Forward

.......PB.. PF
Hi = 814 842
Lo = 335 775
Avg = 597 804
ES = 479 67
SD = 189 21

I don't remember which application, but I too experienced the FPS decreased with more powder. Again, plated bullets. Trail Boss plays great with lead.

 

[GBExpat]

What kind of bullet? ...

Lead, from BadmanBullets.

I hadn't planned on trying any positional tests with Trail Boss since I figured that, considering its volume-filling property, there would be no reason for the exercise.

Perhaps I should add a few tests, just to be sure.

Walkalong, are you sure that you have the PB & PF in the right places over that data? The numbers make it appear to me that you have them reversed.

 

[Walkalong]

That's the weird part. Yes, I am sure about it.

 

[ironworkerwill]

I don't know what would happen with more than a 100% fill of TB. I'm not sure the same phenomenon that occurs with rifle would occur with TB. The stuff is very fast and could be extremely dangerous if compressed. I'm not saying anyone would do that or wants to, I'm just speculating.

 

[jerkface11]

I bet it's funkyness with the chronograph. Maybe you have it set up too close to the gun.

 

[Walkalong]

It repeated its self later. Definitely squirrely.

 

[clone]

Perhaps the powder is not burning completely? Maybe the more powder you add, the less of a complete burn. Wonder if a magnum primer would help?

I don't have a .32-20, but have used Trail boss for .45-70 and 7.62x39.

 

[ljnowell]

Reduced velocity with increased powder charge often indicates max or beyond max powder charge in a rifle cartridge. I have noticed this several times, and started a topic years ago when chronographs became cheap enough the average person could afford. You can research this as I have no idea how it relates to your case, however it I heard little bells ringing some where when I read your OP and thought about this information...hope it helps

I have found it in handguns also. A few years back I was messing around with Power Pistol and some 185 grain JHPs. I wanted to see just what happened up high.

Standard pressure data showed 9.5 grains as the max. I hand weighed charges and chrono'd them. I found that velocity from 8.4 up to 9.3 grains had a fairly steady increase in velocity. At 9.3 grains I gained no velocity in a 10 shot string average over 9.2 grains. I went ahead and shot the 9.4 and 9.5 and even made some at 9.6 and found no increase in velocity, on average. Actually at 9.6 there was an increase of 2 fps on average over 9.2.

Best accuracy was found at 9.2-9.3.

 

[joneb]

I had very erratic and strange results with Trail Boss in .32-20 with a 100 Gr plated bullet.

I tried TB in 38spl with plated once never again, TB works well with lead though.

 

[Walkalong]

My findings as well. Loves lead, hates plated. Go figure.

 

[KSCCHTrainer]

I'm getting good results in .44 special with Hornady's XTP JHP's. Haven't chronographed them, but accuracy at 20 yards out of a 2" barreled Taurus 445 is under 2" from a good rest and tests in ballistic gel show great expansion. Charge I use is 90 percent of the "fill to base of bullet" weight, and as others have stated, DO NOT COMPRESS this powder.

Had a load for 8mm Mauser worked up (around 12.5 grains TB, 209 grain cast lead bullet) that gave better than MOA at 100 yards out of my 98K but had the trajectory of a mortar - LOL. It was surprisingly consistent in accuracy though, go figure.

Jim

 

[Lost Sheep]

An inquiry to Hogdon for load data for TB and jacketed bullets resulted in a "sort-of" non-answer. "Trail Boss does not like jacketed bullets".

TB was developed for Cowboy Action Shooting and thus did not consider that users might have copper in mind. Since then, we have found that TB is usable with copper plated, copper washed and jacketed bullets, but with spotty results, apparantly. My friend and I have found fairly good results in his 500 S&W for lightl loads.

I followed up Hogdon's terse reply with the followup question, "How does Trail Boss express this dislike for jacketed bullets." I was sorely disappointed that Hogdon never made any attempt to reply. Sorely disappointed.

So, Walkalong and joneb, how did you find TB expressing its dislike for plated?

Thanks

Lost Sheep

 

[GBExpat]

... I followed up Hogdon's terse reply with the followup question, "How does Trail Boss express this dislike for jacketed bullets." ...

Hahaha ... me like!

 

[ljnowell]

An inquiry to Hogdon for load data for TB and jacketed bullets resulted in a "sort-of" non-answer. "Trail Boss does not like jacketed bullets".

TB was developed for Cowboy Action Shooting and thus did not consider that users might have copper in mind. Since then, we have found that TB is usable with copper plated, copper washed and jacketed bullets, but with spotty results, apparantly. My friend and I have found fairly good results in his 500 S&W for lightl loads.

I followed up Hogdon's terse reply with the followup question, "How does Trail Boss express this dislike for jacketed bullets." I was sorely disappointed that Hogdon never made any attempt to reply. Sorely disappointed.

So, Walkalong and joneb, how did you find TB expressing its dislike for plated?

Thanks

Lost Sheep

Apparently they don't have much of a sense of humor. I once contacted ATK/Speer/Alliant with a question regarding Gold Dot bullets and got a pretty funny reply, at least they seemed to enjoy the motivations behind my question.

 

[Lost Sheep]

Apparently they don't have much of a sense of humor. I once contacted ATK/Speer/Alliant with a question regarding Gold Dot bullets and got a pretty funny reply, at least they seemed to enjoy the motivations behind my question.

I would have thought the maker of the product would have a bit more invested in the safety of their customers. If they have knowledge that Trail Boss dislikes (their words) jacketed bullets, they would not withhold that information.

My friend and I carefully experimented with his 500 S&W using the jacketed bullets (the only .500 diameter bullets available to us at the time (that were manufactured for .500 AE) and settled on a load that clocked at 800 fps, but not before we flirted with 650 fps.

It makes for a fine introductory load for curious onlookers who would like to try out the big gun. Then they can work up slowly to 1,000 fps, 1200 fps and higher until they decide to call a halt to the escalation.

Some people (sadists?) find it fun to hand a handful of a gun to a new shooter to see their reaction. We find it much more (if subtly) amusing to watch them ease up through the power levels and see who decides to stop, where and their expressions when they do.

But I am still disappointed in Hodgdon.

Lost Sheep

 

[ljnowell]

I would have thought the maker of the product would have a bit more invested in the safety of their customers. If they have knowledge that Trail Boss dislikes (their words) jacketed bullets, they would not withhold that information.

My friend and I carefully experimented with his 500 S&W using the jacketed bullets (the only .500 diameter bullets available to us at the time (that were manufactured for .500 AE) and settled on a load that clocked at 800 fps, but not before we flirted with 650 fps.

It makes for a fine introductory load for curious onlookers who would like to try out the big gun. Then they can work up slowly to 1,000 fps, 1200 fps and higher until they decide to call a halt to the escalation.

Some people (sadists?) find it fun to hand a handful of a gun to a new shooter to see their reaction. We find it much more (if subtly) amusing to watch them ease up through the power levels and see who decides to stop, where and their expressions when they do.

But I am still disappointed in Hodgdon.

Lost Sheep

I agree, if they have information regarding why it doesn't play nice with jacketed bullets they should share that for the knowledge of the reloading community.

As far as people handing someone a cannon to shock them, I can't stand that. It's even worse when they hand it to a young person or woman. I've spoke my mind a few times and stopped exactly that same thing a few times also.