I have a 16" vent rib 45 Colt / .410 barrel & it patterns nicely with regular 2.5 or 3" .410 shells ( that also has the straight rifling screw in choke tube ) though internal on the .410 barrel that barrel is one of my favorite bunny control tools... the one for the 444 barrel is external ( pictured just below the gun, the thread protector is screwed in, in the picture ) the barrel actually measures just over 8" without the choke tube, & 10" with it screwed in
This 44 hotshot barrel has very shallow rifling compared to my other 44 Mag barrel, coupled with the straight rifled choke tube, I expect normal patterns... but will see what I get from the shorter than normal barrel
BTW... my 1st load of shot equals somewhere between 2.5 & 3" of normal shot charge
BTW #2... the .375" round balls fit precisely in the choke tube, so they should shoot a pretty tight pattern for a short as the barrel actually is
In life you either make dust or eat dust...