Jason,
Sorry, but it don't work that way. The Shotgun has a SB-1 Frame, the .44 mag has a SB-2 rifle frame. You could buy a Handi in .44 mag and send that in for the .410 barrel though. H&R/NEF will only fit shotgun and muzzleloader barrels to SB-1 frames. The SB-2 rifle frames can be fitted with rifle, shotgun (except 10ga and Ultra Slug 12ga) and muzzleloader barrels. The SB-2 frame goes through a hardening process to eliminate frame stretch when using high chamber pressure center fire rifle cartridges. I know the .44 mag doesn't fall in the same category, but they had to draw the line somewhere. Would be nice if they were all SB-2 frames, but then the cost would be much more than $89.00 for a shotgun.
Check out this link to the barrel program and read through it, it will answer your question.
http://www.hr1871.com/barrelAcc/index.htm