I decided to break the 444 into two separate threads, one for microgroove and another for the Ballard rifling.
The 444 Marlin has a very short throat. For this reason, some 44 mag bullets with full diameter front bands may not chamber in the 444.
Here's a couple of suggested nose designs for the 444 with microgroove barrels. They will produce a cartridge overal length of 2.565".
A bore riding nose.
Or a reduced diameter nose.
Glen Fryxell used a reduced diameter nose in this article: http://www.leverguns.com/articles/fryxell/444marlin.htm