300Win;
I would think that the Handi's would handle the Buffalo Bore Ammo, in 44mag. due to it being a relatively low pressure round comparied to the 25-06, 30-06, and 280 Rem that have a pressure of about 50,000 psi +. Plus it being a handgun caliber, I see no reason for them not to be safe.
But that's my 2cents, I could be wrong.
Dennis