Buy the Lyman Cast Bullet Handbook. They have laboratory proven data using small amounts of pistol and shotgun powder in as many different cartridges as you'd find in a normal reloading manual.I've seen thousands of reduced loads for 30/30 but the source of these loads would make me hesitate. TB is an established source. Seen loads with 2400, 231, Unique and many others but they'd be a jump of faith.
160 GR CAST
Powder-start-velocity-pressure-max-velocity-pressure
H4895-17.5gr-1351-15,200-21.0gr-1562-23,100
H4198-15.0gr-.1420-15,000-17.0gr-1616-20,600
Trail Boss- 6.5 gr-997-20,500-9.0 gr-1195-29,100
This is the information from the Basic Manual that can be downloaded from the Hodgdon website;
I'd suggest that Trail Boss in this case and in many other rifle calibers is a poor choice. Notice how it gives a high pressure with a far lower velocity than for the other powders? This is simply not a wise choice for a rifle caliber powder IMO.
Now this all changes for handgun calibers where it works very well. But it's this issue with high pressure for low achieved velocity that brought me to state that it's not a miracle powder in my earlier post. And this issue shows up in other rifle calibers where it is listed as an option with the same issue.



























