ArJ, linky...
thoughts??
http://10mm-firearms.com/reloading-10mm-ammo/using-true-blue/
I'm not sure what your questions are.
IMO the most responsible answer was the first one from robert4. He's technically correct, but I have used an even faster powder with 185gr. XTp in 45 ACP and achieved very high velocities. Ask 20 reloaders the same question and you will get 20 different answers.
I am sure you are aware on the many nuances of various powders and how they relate to barrel length, bullet weight, and the durability/design of the gun's barrel and frame. Ideally you want a powder that will push that bullet out the length of the barrel at optimal speed without placing excessive or even catastrophic chamber pressures on the brass or gun, while maintaining accuracy. This is why there are well over 150 different smokeless powders out there.
Understand that I am NOT a 10mm reloader. I do know that the 10mm cartridge can handle almost twice the pressures that a .45 ACP can.
185 GR XTP's (which I have a thousand of in .451 JHP) is a medium-heavy bullet. I just checked my reloading logs and the best I have managed using 185gr XTP's was a range of 1085-1157 fps using 8.2gr. of Unique powder, large pistol primers, +P Nickel Brass, and 1.235" OAL. This is pretty stunning for .45 ACP +P and they showed no signs of overpressure in my Glock 21, but showed slight signs of overpressure in my STI VIP 2011. I wouldn't shoot these HOT loads every day, but that was the limit I reached.
I'm guessing with 10mm 185gr XTP you might be able to push 1350fps safely with the right powder, right OAL, and a solid gun. I've seen some push 1500fps, but that is asking for trouble IMO unless you have along barrel.
I assume you know how to work up a load and constantly check for signs of overpressure on the brass and primer. My favorite powder for pushing 185-200gr bullets in ~ 4-inch barrels are HS-6 and SR-4756. Do you have a list of all powders ordered by relative burn rate? If not, I have attached a couple versions to this post for you to download. This is useful for figuring out what to experiment with next. You can move up and down the chart to see what effect it may have. Longer barrels can benefit from slower powders and vice-versa.
The "Unique" powder I used to achieve what I consider crazy velocities from my short barreled .45's is a considerably fast burning powder. I'm sure the chamber pressures are initially very high as it tries to move 185 grains of copper/lead along.
Judging from the link you sent, TrueBlue powder does not seem to me the best powder if your trying to achieve high velocities. I've never used it, but the numbers on that page speak for themselves. It looks like a good safe middle of the road powder that will be easy on the gun. I am achieving similar or better velocities with .45 ACP. 10mm should be able to achieve higher velocities than my .45's for sure. I'd have to do a lot more research if I were going to reload 10mm. That's just my initial impression.
Be sure to log EVERYTHING you do. Do you have a chronograph so you can know exactly what your results are? I just found out that they have a Bluetooth adapter for mine which lets me track and log results on my phone. It also reduces straining to see the damned numbers after each shot since they are displayed on the phone. When I get better it's the first item on my shopping lost. I lay out my reloads for testing in a specific grid in an ammo box. After each shot is fired and logged I place the brass upside down in the same spot it came out of. When I'm done I take a close up photo of the box for future reference and analysis. If I see any signs of overpressure I will shoot maybe one or two more to verify and then stop. I also note if accuracy seems affected by the various loads, but I don't do much of that until later when I settled on a safe load. I'll make a plinking load and a safe hot load. For CCW I only use store bought +P ammo for obvious reasons.
We should get a 10mm plate for my progressive press and hang out sometime reloading and listening to music.
Cheers,
AJ
Cheers,
