Important info about Tin Star vs. Trail Boss for reduced loads in handguns

[John Ross]

Thoughts on TinStar powder compared to Trail Boss Mods may see fit to copy the thread to a different section...

Here's some info some may find interesting. Doing some checking with Quickload, two things become apparent.

First, the people who claim that TB is safe at 100% loading density in any cartridge are probably correct, except perhaps in the very weakest, junkiest firearms made originally for BP loads.

Doing a quick check of a .50 BMG round with an 800 grain bullet seated only .200" deep, 85 grains of TB is 100% load density, and gives 38,200 PSI and a muzzle velocity of 1520 FPS in a 26" barrel. Interestingly, raising the bullet weight to 2000 grains raises the pressure only a bit, to 39,500 PSI with M.V. of 978 FPS. Going for full-on crazy with a bullet of 7000 grains (one pound) gives 40,200 PSI and 525 FPS. This is all with the same 85 grain powder charge.

Second, according to Quickload, TinStar has almost exactly the same burning characteristics as TB on an identical weight basis. A charge of 85 grains of TinStar gives similar numbers as TB in these .50 BMG examples, and simulations on other cartridge/caliber combinations I have tried give similar results.

HOWEVER, and this is a very big deal, TinStar is much less bulky than TB. A charge weight that is 100% density with TB is only 67% density using TinStar. If we raise the charge with TS to 100% in our three .50 BMG examples, we get a charge weight of 126 grains and pressures of 66,000 to 68,000 PSI. This is not enough to bother either a Browning MG or a good bolt gun in this caliber, but it's an indication that TinStar carries some serious risks for the handloader with either a cavalier attitude or incomplete information. I'll explain:

Let's switch to the .45 Colt cartridge with 250 grain cast bullet. A charge of 8.9 grains of Trail Boss gives 100% loading density, 16,000 PSI, and 900 FPS out of a 5" barrel. This is 2,000 PSI above SAAMI Spec, but probably not enough to damage an original Colt.

Things get scary when we switch to TinStar. The same 8.9 grain charge gives only 67% loading density but a pressure of 17,400 PSI. Raising the load density to 100% gives us 13.5 grains of TinStar which gives a pressure of 38,000 PSI. Bye-bye original Colt...

TinStar is an interesting powder that can be used for reduced loads in modern guns by shooters who want more oomph than TrailBoss can deliver, but IMO in these cases there are always better choices.

As an example, a 100% density TinStar load in my beloved .500 S&W (24.5 gr.) with my 400 grain Alley Cleaner bullet gives 1200 FPS at 50,000 PSI. At an 80% loading density (19.6 gr.), we get 1060 FPS at 34,600 PSI. Neither of these loads will hurt the gun, but a powder like Ramshot Enforcer will give 1200 FPS at 23,000 PSI, the same velocity as the top TinStar load at less than half the pressure.

Even if TinStar were half the price of other powders, I don't think I'd ever use it. I think we're going to see some original Colt SAAs (and others) blown up with this powder by folks who mistakenly believe they can treat it like Trail Boss...

[Bubba w/a 45/70]

Very astute observations.

Hopefully this will be read before someone tries this, or they do their own research.

......but probably not.......

[Silver Jack Hammer]

Very interesting, thanks for posting. I cringe at the idea of another Colt’s getting blown. I’m loading a bunch of Trail Boss right now for this years matches -just because I have a bunch of Trail Boss and I want to get rid of it.

Light loads and large case capacity like the .45 Colt is a recipe for disaster especially for those loading by volume and loading cowboy ammo which is loaded at high volume on a progressive.

Personally for cowboy I use Schofield .45 brass from Starline and full weight 230 gr. boolits. I’m currently loading one full grain over max by weight as per the current edition of my favorite loading manual and still under factory velocity for the Schofield. My velocity deviation is extreme, but I don’t want to get DQ’d for failing to meet powder factor.

I’ve never tried Tin Star and don’t plan on it. Thanks for posting.

[35remington]

Honestly, if quickload predicts safe pressure with a bullet near 10 times normal weight using a 100 percent density load of trail boss in a 50 BMG, I highly suspect something is wrong with the quickload calculation.

Does not pass the common sense “smell” test.

Any predictive program has an envelope beyond which it is not accurate. I suspect that may be the case here.

[John Ross]

Honestly, if quickload predicts safe pressure with a bullet near 10 times normal weight using a 100 percent density load of trail boss in a 50 BMG, I highly suspect something is wrong with the quickload calculation.

Does not pass the common sense “smell” test.

Any predictive program has an envelope beyond which it is not accurate. I suspect that may be the case here.

I would normally agree, but TB is by design so bulky that it gets all consumed in short order in virtually any barrel length, without the pressure progression we see in "normal" powders. Others have tried it at 100% density in things like .30-06 with bullets of 70 to 220 grains and have seen the same results. I believe QL on this one.

[ReloaderFred]

The original post refers to experimenting with both powders in making up loads, but if published, tested data is used, then they're both safe to use as intended.

Hope this helps.

Fred

[John Ross]

The original post refers to experimenting with both powders in making up loads, but if published, tested data is used, then they're both safe to use as intended.

Hope this helps.

Fred

Some of us are old enough to remember the First Edition of Speer's reloading manual #8...

The point I was trying to make is that it's been widely stated that the "starting load" of Trail Boss powder is 70% of net case capacity under the bullet, and a max load is 100%.

Now many people are saying that Tin Star is "another reduced load Cowboy powder like Trail Boss."

Making the leap from this second statement to applying the Trail Boss "rule of thumb" to Tin Star could create serious problems.

Just sayin'...

[35remington]

I guess I will believe it when someone actually measures such a thing from actual use rather than predicts it from a program. Especially with a ten times increase from a standard weight bullet, rather than a slight percentage increase in the 06 over standard weight for caliber. 220 grains is a much smaller incremental change (25 percent or so) from a more standard 150-180 grain weight. Your cited 06 testing is in no way the same thing as multiplying the standard bullet weight for the caliber tenfold, so feel free to suppose I hail from Missouri in that regard.

I always remind myself the real science is in the actual testing, not the predicting. I won’t hold my breath waiting for someone to shoot an 1800 grain bullet out of an ‘06 or a one pounder out of a BMG, though!

[John Ross]

I guess I will believe it when someone actually measures such a thing from actual use rather than predicts it from a program. Especially with a ten times increase from a standard weight bullet

SNIP

I don't blame you for being skeptical. One thing to look at if you're really interested in this is to research shoulder fired harpoon guns, see who has one and see if they'd like to try it with Trail Boss.

https://books.google.com/books?id=nN...%20gun&f=false

I own a Greener 16 ga. harpoon gun. I'd have to weigh the harpoon but I think it's over a pound. I've never shot it.

[PbHurler]

I do love me some N32C (Tin Star). I've found it as a great replacement for the now discontinued IMR SR7625 that I'd standardized on for years, for my plinking loads in .357 & .44 (mag)

Picked up 10lb a few years back from Recobs @ 15.99 / Lb

[LUBEDUDE]

Thanks for the info John Ross.

I have some experience with Trail Boss but none with Tin Star. I was under the impression that Tin Star was just another Trail Boss. So glad you pointed out that there is a significant difference.

[ReloaderFred]

I use a lot of TrailBoss powder with cast bullets, and even though I've been reloading for over 54 years, and load for 32 different calibers, I still use published data for my loads. That isn't to say that I haven't experimented with loadings that aren't in the books, as I have, and my smokeless load for my .45-120 Sharps is one I came up with through much experimentation and testing, along with some loads for my 9x25 Dillon handguns. These are all in modern firearms, built from modern steels, and I used published load data to start with.

I also have a personal policy of not posting any of my loading data on open forums, since it's too easy to mistype, transpose or just plain not remember correctly.

Hope this helps.

Fred

PS: I also have, and use, QuickLoad, but I don't take it as gospel....

[Bigslug]

John,

Good cautionary intel there. Potentially sounds like a situation similar to Hodgdon Triple Seven being about 15% hotter per unit of volume, necessitating the occasional use of spacer wads if you want to duplicate original load specs. This made for a merry bit of head scratching when my father and I sat down to figure out the charge for the 1866 Chassepot rifle he was gifted by a friend. Being a "paper bag" cartridge of Dreyse descent, it's the only time I've been involved with a round where powder charge determines headspace.

Sounds like this Tin Star is potentially pretty useful stuff, provided one reads the directions. I guess my question would be how does it compares in bulk to things like Bullseye and other powders that are popular in little rounds up to perhaps .45ACP size? If the same safe velocity is achieved at greater load density, might it not make for a more consistent burn for match ammo?

I know why you did your extreme example, but the notion of a Trail Boss SASS load for .50BMG is making me chuckle.

[MOA]

Thanks muchly for that information.

[35remington]

The reason I am skeptical is for those calibers where multiple bullet weights are tested, pressure goes up substantially with increasing bullet weight and allowed maximum charges decrease substantially in weight when bullet weight goes up. This per Hodgdon and their pressure tested data.

I cannot speak to all relationships, but a charge of Trail Boss that gets equivalent velocity to a charge of W231 with an 85 grain bullet in a 25-20 occupies two and a half times the volume.

[Cosmic_Charlie]

Trail Boss sounds like just the powder for one of the little Lee hand loaders.

[rockrat]

"bigslug"---no offense, but I had to laugh at your post because I do have a TB load for an 850 gr boolit in the 50bmg!!!! 1600 fps and about an inch group @ 100yds. Makes for a nice "plinking load", when I want a bit milder load

[John Ross]

"bigslug"---no offense, but I had to laugh at your post because I do have a TB load for an 850 gr boolit in the 50bmg!!!! 1600 fps and about an inch group @ 100yds. Makes for a nice "plinking load", when I want a bit milder load

See, everybody, I'm not as crazy as it might appear at first blush... Validation!

[John Ross]

John,

Sounds like this Tin Star is potentially pretty useful stuff, provided one reads the directions. I guess my question would be how does it compares in bulk to things like Bullseye and other powders that are popular in little rounds up to perhaps .45ACP size? If the same safe velocity is achieved at greater load density, might it not make for a more consistent burn for match ammo?

I've never used it and Vihtavouri lists no data for it in .45 ACP. SAAMI max pressure for .45 ACP is 21,000 PSI.

Fooling around with Quickload reveals that loads with jacketed bullets 180-230 grains in weight hit around 20,000 PSI with Tin Star using charges that are around 90% loading density. Published loads for Bullseye get 19,000-20,000 PSI at around 60% density, and loads with Titegroup hit this level around 45% density.

Hodgdon lists Trail Boss loads for three cast bullets in .45 ACP on their site. Max loads with TB are around 16,000 PSI according to Hodgdon and appear to be at 100% density.

[opos]

Trail Boss sounds like just the powder for one of the little Lee hand loaders.

I had laid off reloading and shooting much for a few years...had too much invested in t ime and money in offshore fishing so that got the call...when I started back loading I didn't have much equipment so bought one of the little Lee hand presses and a 5-0-5 RCBS scale on e bay and misc other stuff where it showed up....I loaded 45Colt a bunch and really enjoyed it...slow but heck that is part of the fun...it does a great job...I use Missouri #4 Cowboy bullets with a 12 hardness and I shoot an original large frame Ruger Vaquero and a full size Ruger Blackhawk/45 acp combination....I don't get nutty with the crimps...won't tell you how much trailboss I shot under the 200 grain MGC RNFP pills but it was a very moderate load...accurate, nice and the Trail boss smells good...I'm still loading their bullets but now using the coated ones...it's wonderful if you don't cast and I can't cast for physical reasons..