In the Henry, I'm gessing it's the new Henry Big Boy, but in any tube magazine rifle, you need to use a RNFP bullet. For target use and for metal targets I like a 200grn RNFP hard cast bullet similar to the ones sold by LazarCast. I use a moderat load for target shooting and usualy use a 44spec case. Normaly I only load the 44mag case for hunting.
Greeenriver(7grns of HS6 under a 200grn RNFP makes a plesant target load in a 44spc case.)
PS: There are many better powders than HS6, but I have 8lbs of it and can't see buying others when the HS6 will work.