ADI Trail Boss Powder


I’ve Been loading ammo with Trail Boss for a few years now and I must say it is the most versatile powder on the market (at least in Australia), Its can basically be loaded into any centre fire round and even in very limited situations into shotgun shells.
I have loaded Trail Boss into 38 spec, 357 mag, .222, .303 brit, 7.7 jap, 6.5x55, 8mm mauser, .308 and probably some I can’t remember off the top of my head right now.
Trail Boss is an extremely bulky powder and generally is loaded by volume as apposed to by weight, by which I mean it is usually loaded somewhere between 70 - 100% of the free case volume. basically as long as its not compressed by a projectile (COMPRESSED LOADS OF TRAIL BOSS ARE EXTREMELY DANGEROUS AND WILL MOST CERTAINLY CAUSE PRESSURE SPIKES THAT MAY KILL YOU) you can fill the case and you will not create any pressure problems.
As far as I know it was created for western action shooters who were only requiring low pressure loads for shooting relatively large targets at close distances, but it has found use in the creation of subsonic hunting loads, milsurp plinking loads, handgun comp loads and although not recommended by ADI as a shotgun powder (due to shotshell’s generally being compressed by a wad) I have talked to a bloke who has been experimenting with loads of brass 12ga shells loaded with Trail Boss and full bore round ball slugs.

I love Trail Boss and I know some of you out there do too, I’d love to here what calibre’s you have loaded it into.

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Uh, yes… @GUN-DMC has introduced me to this drug and I must admit, this is my go to powder for a lot of plinking… It makes hooting a 45-70 like you are shooting a 223 and a 308 like a, well, 223. And a 223 like a… I don’t know, never loaded a 223 with Trail Boss :stuck_out_tongue_winking_eye:

To expand on some things… ALWAYS start low and work your load up. Even with a safe powder like Trail Boss.

Trail Boss has a very important rule: NEVER COMPRESS THE CHAGE. This is really important.

So, how do I calculate my loads. This is the easy part. First you need to calculate your maximum load. You do this visually! Yes, by looking.

You maximum load is the amount of powder you can fit into the case, with a seated bullet, while the bullet is not touching the charge. Once the bullet touches the charge (the powder), it is considered compressed and will change the burn characteristic of the powder - this is where it gets dangerous (i.e. destroy your gun or yourself).

In reality it’s pretty easy, align the bullet on the outside of your case to see how far you will seat it… Mark the case with a pen - where the bottom of the bullet. At this stage, your maximum charge becomes the amount of powder you can fit into the case below that line.




Fill the case to the mark and then weigh the charge. Congratulations, you have now calculated your maximum load.

So, how do you calculate the starting load? It’s 70% of your maximum load. For example, if you can fit 12 grains of powder, at maximum. Then, your minimum load is 8.4 grains (70% of 12).

To be perfectly honest, this is a very lite recoil powder and heaps of fun to shoot, so you want to aim at the max charge, but you need to work up to that.

As per the example above, start at 8.4 grains. Load a couple and test them. No pressure signs? Move to 9 grains. No pressure signs? Move to 9.5 grains and keep working up to your calculated max. That’s it.

After you seat the bullet, give the loaded cartridge a gentle shake next to your ear. If you hear the powder shaking, it’s not compressed - simple.

Now, when I say it’s fun to shoot, it’s FUN to shoot. It’s made specifically to take up lots of space (i.e. fit a lot less Trail Boss in a case than any other powder). This means that you can have a very lite recoiling fun plinking round.

Have fun!

Fun tip:
Image of TB tub above is 1.5kg and it takes up the tub, while the same volume of ADI AR2208 (Varget) be 4kg. Considering the larger volume and less charge, this 1.5kg goes a very, very, very, very long way.

What have I loaded?

  • .308 with 168gr hard cast bullets (my dedicated plinking 308)
  • 7.62 x 54R with 174gr copper jacketed bullets
  • 8 x 56R with 200-something grain copper jacketed bullets
  • 44 Rem. Magnum with 200-something grain hard cast bullets
  • 45-70 Gov. with 500gr hard cast bullets
  • 303 Brit. with 174gr copper jacketed bullets

How does it feel shooting these monsters? Awesome, sort of like 223, but felt recoil is subjective. 45-70 felt a little harder, but only a little, considering I was plinking 500gr slugs with it through a very lite rifle.

These are more or less subsonic ('weak) rounds. For example, my 7.62x54R rifle had to have sights set to 500m give or take, to sight in at 100m.

Trail Boss in a 223rem is a great pest control round out to about 120m. Past that it starts dropping like a stone. I use it behind a 50gn bullet in my 18" barrel for 1850fps. That’s the speeds you get from a 40gn bullet in 22wrm. So, having a hot 22mag that you can load with highly frangible bullets is very handy. The report is also much quieter so your not scaring every pest animal aeay with the first shot like with a full load of BM8208.

With some tweaking, i have managed to acheive around 1moa at 100m. After originally being unimpressed with consistency, come bright spark suggested trying small rifle magnum primers for a more even ignition. It worked and so that is what i use. Make sure you do NOT mix these primers up with your full 223rem loads!!!

Got a full can, I haven’t tried yet! Had it for 2 years lol

Mate I have only starting experimenting with Trailboss. I must say it is becoming addictive. I have been using it in my 300AAC for subsonic loads. I intend to try it out in all of my other cartridges too, not out of necessity, just for a bit of fun to see what I can develop.

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It is a very cool powder for plinking :slight_smile:


Seen some very accurate subsonic cast bullet loads in 303 using TB. Great for short range econimical target practice loads. I need to try it in my 7.62 Omark for some 50m cast bullet fun, on the 50m ISSF target.

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Loaded some subsonic Lee 155gn cast bullets for my 308 Omark FB rifle last Sunday…
8gns of Trailboss…Should be fun to see 50 and 100m accuracy…

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I had heaps of fun with TB over a three year period. Loaded 308, 30-30, 243, 22-250 & 223.
My favourite was the 30-30. Basically turned into very comfortable to ‘Pop Gun’ :+1::rofl:
As as already been said, NEVER compress the charge and you’re good to go. :sunglasses:

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Yes its certainly very timid…Its only a subsonic powder for me…

Tested the 8gn TB Loads…well they show seroius accuracy potential! Only 50m at this stage, easily 1/2" group, off a shitty rest. Will put photo up soon…They were wearing a GC, going to try them without a GC, on a proper 50M ISSF target.

Initial sighting in…started out high left…theres a few in the middle…Certainly shows some accuracy potential.

10 gr of T.B behind a 170gr cast GC bullet is very accurate in my .30-30 lever-guns. Mild as hell to shoot.

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