Yeah, I'd be happy to put together a tech notes on my pressure/velocity work with the 44 mag. That is, if it's ok with Marshall.
Right now though I can give you at least some perspective on my high end work with the 44 mag and with my understanding of James Gates work with the 44 Max. (James, feel free to correct me here).
The high end of velocities I get with the 44 mag (bullets seated out as far as the H&R rifle will allow) is still below the 44 Max. I can't prove it but I think the 44 Max is running less pressure than my high end (Redhawk pressures) loads. The 44 Max is certainly a more flexible rifle cartridge the the 44 mag. It might be fair to say that the absolute top of what can be done with the 44 mag in a rifle roughly touches the bottom of what the 44 Max can do. I suppose there is a similar relationship between the 44 Max and the 444 Marlin. I believe James work with the 44 Max is with shorter barrels than my 22" H&R.
You should also note that my loads will not cycle thru an 1894 lever action. The 44 Max was designed to work in 336 lever actions as well as single shots. The accuracy issue is typically because the single show H&R's often shoot great. All my tested loads were very accurate save but one (and that bullet when seated back in the crimping groove with the right amount of powder was the most accurate load of all). Expect the 44 Max to be a moa cartridge in the right rifle.
Hope this helps a bit for now. By the way, I am getting a 44 Max next year.
Against the wind...