.45 Colt Handloading (250 grain LRNFP + Trail Boss) Part 1

***DISCLAIMER***

This post contains handloading data.  It was created for my firearms and may not be safe for general use.  I cannot be held responsible for misuse of this data or for typographical errors.  Use at your own risk!


(continued after the jump)

This is my first new handloading project in a while, and it's going to be something of an experiment.  I'm looking to make a general purpose .45 Colt load for my new Ruger Blackhawk (a 250 grain bullet at around 900 fps) that is easy and safe to load, so I chose Trail Boss as the powder.

I like the idea of Trail Boss: a bulky powder with a fast burn rate that's perfect for relatively low velocity loads without running the risk of being able to double-charge a case.  The bulkiness of the doughnut flakes also makes Trail Boss really easy to work with, since it's hard to spill lots of little granules all over the place when you're manually weighing every charge like I have to.  Someday I'll get an automatic powder measure, but until I do it's a nice bonus.

There are a few "rules" about loading with Trail Boss.  One is NEVER COMPRESS TRAIL BOSS.  This will cause pressure spikes.  Two is NEVER BREAK APART GRANULES OF TRAIL BOSS.  This will apparently change the burn rate severely.  Those two are pretty easy to follow.  The next "rule" is more about figuring out what charge to use.  Assuming you don't have a good reference saying otherwise, you should be safe (in modern firearms, as in NOT a Colt SAA or clone) to fill the powder space 50% up to 100% full without pressure problems, because of the bulkiness of this powder.

That third rule, plus the Hodgdon annual manual gave me an idea of where I should be able to start.  Hodgdon shows a "max" load for the .45 Colt of 5.8 grains behind a 250 grain cast LRNFP bullet producing 12,700 PSI.  Even though CUP does not equal PSI and there is no simple conversion, they seem to feel this is within the 14,000 CUP SAAMI maximum.  That is a limit set with older, weaker guns in mind.  Unfortunately, there is no Trail Boss load listed in the "Ruger, Freedom Arms & T/C only" section (30,000 CUP max) where my Ruger Blackhawk fits.  Referring back to "rule" 3 above, I marked a case with the bullet depth and filled it with 5.8 grains of Trail Boss, which only filled around 60% of the powder space.

So where do I go from here?  Settle with the 5.8 grain load at a cowboy action-tastic 727 fps?  I don't think so!  My next step was to find comparable data with a similar sized case: the .454 Casull.  Now the Casull has a somewhat larger case than the Colt, the Casull OAL is 1.77" while the Colt OAL is 1.6".  This doesn't add a whole lot of extra capacity (the main reason the Casull is so much more powerful than the .45 Colt is because it is designed to be loaded to pressures of 60,000 CUP).  The Hodgdon manual lists a starting load of Trail Boss under a 250 grain LRNFP bullet of 6.7 grains, producing 14,800 CUP and 862 fps.  Their max load is 9 grains, producing 19,300 CUP and 1011 fps.  This is much closer to where I want to be.

Doing some rough figuring and measuring the approximate powder space filled by the load, I decided to start at 7 grains of Trail Boss.  This should be approximately 90% of the powder space, which hearsay leads me to believe will produce the best accuracy.  Also, by my rough estimations, I can't see any reason why this load will push the 30,000 CUP max for my revolver.  Really, I doubt it breaks 20,000 CUP.  If this load produces about 900 fps, is acceptably accurate, and shows no pressure signs, then I'll probably settle right there.

Components used:

• IMR Trail Boss powder
• 250 grain lead round nose, flat point, plain base bullets cast by Bacon's Bullets here in Iowa
• Wolf large pistol primers (domestic brands are a little scarce right now)
• Remington .45 Colt cases

Here are the first 12 test rounds and some of my other loading supplies:

Now to find some time to go to the range...