Hornady makes two different 240gr XTP’s in .45.
One is the mentioned 800-1,600 version for the .45Colt. The other for the .454Casull and .460S&W. Expansion is non existent on .45Colt levels.
At 850fps the expansion with the low pressure/velocity version is still minimal.
For my purposes, a 255gr RFN cast is superior. Approximately 100fps greater velocities are possible at same pressures and with a softer alloy, expansion is just as likely as with much more expensive jacketed bullets.
My cast 255’s (Lee 6-cav mold) cost me practically nothing. (Scrap lead).
Though, I have a quantity left from 20yrs ago when I bought 1,000 XTP blems…
Over 19.8 gr of #2400 (Ruger ONLY max load; Nosler Manual), they shoot <2”groups at 100yds from my Winchester M94 XTR @1,700fps.
I’d recommend LongShot powder for the .45colt. It under either a 255gr Lee WFRN or RCBS 270gr SAA SWC. It’s what I use in my S&W M25 Mountain Gun.