Shooters Forum banner

Trailboss powder loading formula

22293 Views 16 Replies 9 Participants Last post by  Lane
I was on another forum and there is a bit of a disagreement on the loading of Trailboss powder. IMR load data shows a max load for 45 colt of 5.8gr at about 12,700psi with a 250/255gr bullet. Also on IMR website (same site as load data) there is a couple paragraphs describing how to come up with "your" reduced load using said powder. This is accomplished by determining the space your bullet occupies in the case and filling the case with powder to that point. (NO COMPRESSING) weigh this amount and this becomes your MAXIMUM load. Use 70% of this amount for a start load and work up toward your max load looking for the most accurate loading for your gun. My measurements are: 45 colt starline brass, 255gr Lee RNFP, I can get 8.5gr of trailboss up to bottom of bullet with no compression, this would be my MAX load, 70% of this is 5.9gr as a start load. As you can see this is over the max load info of 5.8gr. in the load data. WTF over..:confused: anybody got an answer for this one?? Don't say call Hodgden, tried that, they ain't talkin..Another question, if the 5.8gr. load has approx the same pressure as say, 8gr. of Unique why is the recoil so much less? Seems like every time I increase pressure in a load the recoil factor goes up...I may be sly like fox, but I'm also smart like tractor..
1 - 2 of 17 Posts
Why companies get headaches

You are looking at load development for cartridges where the working pressure is at least 30k psi and trying to use it for a cartridge that is set for 15-20k psi. You have load data showing actual pressure so you know that, unless you are intentionally loading for higher pressures in a gun that can safely handle the higher pressure, you can not increase the published load.
Now, if the 70% load is over the published max load, you need to bring that to their attention.
However, any reloader starting at the 70% load is responsible for determining the max load for themselves. The max load they have you determined is just the max load without compression and that is the max load in your gun that is safe, provided the pressure it generates in safe in your gun.
The point is that no compressed load can be considered safe.
See less See more

As far as I can see, you are trying to confuse yourself.
As I said, if the 70% load is over their recommended max, you need to tell them.
Any load above the 70% level is YOUR responsibility to determine if pressure is proper for your gun. The max load, as I said, is simply the maximum safe load if the pressure is safe in your gun. The point to the max load is NOT TO EVER LOAD A COMPRESSED LOAD--don't even think about it. If your gun could handle 60k psi, they would still warn you not to even think about a compressed load. Max in this case is not in reference to your gun, it is in reference to any gun any where made by anyone.
You know what the max recommended load is from their data so you have no excuse to go over. If you didn't have that data, you are still responsible for any load over the 70% starting load.
I think I am making myself clear and I thought that IMR/Hodgdon was quite clear, but maybe not....
See less See more
1 - 2 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.