I've chased that rabbit down the hole for years. The seems to be a real disconnect from reality on most of the data out there. Jacketed loads are pretty much by the book, no surprises there. But when it comes to cast bullet loads, the data has to interpreted. IOW, if you do not have the exact bullet that the data is for, the data may not apply, even if the bullet weight is the same.
I don't have Quickloads, but from what I know about the program, that is probably the best source for load data. And if you don't have a chronograph, you are just whistling Dixie.
I've tried a few different cast bullets, and could pass on my experience if I have used the same bullet. What bullet are you planning to use?
Trail Boss is a fairly versatile powder, but it has some quirks. Some of the earlier information about it was very misleading. There is a 70% rule of thumb, but it has to do with the internal volume of the powder chamber. Water is one gram per cubic centimeter, so I use the weight of water to determine the volume. In a nutshell, I seat the bullet I want to use in a sized but unprimed case. If the bullet does not have a flat nose, I file it flat, so it can sit on my digital scale, primer pocket up. I weight the bullet and case. Then I take a syringe and fill the powder chamber with water, to the level where the flash hole has a bit of water in it, but the primer pocket is dry. I then subtract the weight of the dry bullet and case from this new weight. The difference in weight in grams is the same as the volume in cubic centimeters. You can use the VMD of Trail Boss and do the maths for the grains of powder that will fill the powder chamber with the bullet seated. Or you can cheat and look at the LEE dipper chart and pick the dipper that is the closest to the volume you have.
Now you can use the 70% rule of thumb. 70% of the grains of powder needed to fill the powder chamber is the starting load. Compare this to the loads listed for your cartridge in the Hodgdon data. If the starting load that you calculated is lower than the max load listed you are safe.
Trail Boss is capable of some pretty high pressures, however the energy is not there, so the velocity will be low WRT the pressure.
Below 70%, Trail Boss starts to experience erratic ignition, and you can see that on your velocities. The Es and Sd numbers will be large. Sometimes you can fiddle with selecting a different primer, but in addition to erratic ignition, Trail Boss starts to burn dirty, lots of soot and crud.
My latest loads that seem to work well are with two LEE bullets. The first is a LEE 429-200-RF, and the second is a LEE C429-240-SWC, and it has a gas check.
To illustrate my Trail Boss calculation, the powder chamber volume was 1.63 CC, for a powder weight of 7.4 grains for 100% load density. 70% of that is 5.2 grains. That will be my starting load.
But before reloading I checked the Hodgdon site.
Their 200 gr bullet data is:
It appears as if their data does not apply to my bullet, the max load would be compressed and the min load is more than what I calculated and has more pressure than my bullet can handle.
I loaded my load:
Calibre 44 Remington Magnum Date Loaded 2021-11-25
Powder Trail Boss Weight in Grains 5.2
Bullet LEE 429-200 RF Weight in Grains 206.5
Primer CCI 300 LP Loaded OAL 1.53
Case W-W SUPER 44 MAGNUM Weight in Grains 110
Times Loaded Number loaded
Firearm Little Tony Barrel clean/fouled
Velocity Av 755.6/751.5 Es 20.5/25.36 Sd 8.24/11.13 Shots 5>/5<
Comments: Cleans up the leading, cowboy accurate.
The chronograph shows I'm getting decent ignition, and the bullet is going slow enough that it doesn't lead the barrel.
I shoot cowboy action, this load is light enough to be used all day, it is very mild, and Cowboy accurate.
My other load is for the LEE C420-240-SWC. I measured the powder chamber volume with this bullet seated.
The internal volume of a 44 Mag case with a 429-240 SWC is 1.36cc @1.57" OAL.
For comparison, a 44 Spl with a 429421 Keith has an internal volume of 1.34cc @ 1.56" OAL.
Therefore, for this bullet I would be best to just use data for the 429421 in a 44 special. To that end I loaded the Skeeter" load, 7.5 grains of Unique and duplicated his velocity of about 1000 fps. The gas check helps keep my soft cast bullet from leading.
These two loads are superior to most of my other cast bullet loads. YMMV. My data goes back 10 years, I've been at this one for a while. Many #s of powder and lead, and at least 7 guns, most of which I sold out of frustration.
Nitro