Would like one powder for AR and Handi. Simple as that.
You make some good points for those loading for only Handi..
Having the handi lets you do some very cools stuff. Handi loads only:
90 Gr XTP with Trail boss
Cast Missuri heavy lead with 2400 unique of Lil Gun
Then have your AR only loads
220 SMK and A1680
208 A-Max with A1680
110 Barnes black tip with LilGun (works in both guns)
any of your supers will work in both..
But no way wll you mix up a 90 Gr XTP or the Lead bullets with your AR loads.
you get the best of both worlds. 1000 rounds per lb for the lead bullets More accurate and a LOT quieter.
BUT if you want the same bullet for both platforms you are sorta stuck using the AR friendly load and living with it in the down sides of the load in the Handi.
With some thinking having one extra lb of powder is really not that big of a deal.
My problem is having loads that LOOK the same and not knowing what they are. (yes I mark the boxes) but still it can lead to shooting a super instead of a sub if they look the same.
My lead sub 190 I use American Select in the handi very very quiet and very low ES, I loaded 20 at 1580 fps with A1680 to cycle the AR as a low cost super. Unless I weigh them I can't tell them apart.. So I have the MAG labeled too. A sticky marked SUPER ... Since I test a LOT of loads If you are not very careful it can lead to pulling bullets.
Reducing components is a good idea also is having flexibility and having the best ammo for each rifle ..
A bigger problem is the scope/sight difference for each. Keeping the ammo straight is fairly easy.. but keeping track of the click changes between each is a PITA. Add to that different silencers and it's all messed up!