My advice is worth exactly what you paid for it but Uberti is offering their 73s in 44 Mag. The hornady Leverevolution and superformance Ammo are supposed to use a proprietary slow powder that gets the extra velocity without busting SAMMI pressure limits on a particular cartridge. SAMMI pressure limits of 45 colt are way below 44 mag.
You could call or e-mail Hornady and ask them.