andy52,
If you are able to kneel at your shooting bench, it will keep you back straight and let you rock with the recoil.
Also, a bag of shot, kitty litter, or a pc of foam board is your friend at the shooting bench.
Great Rifle!
Also try finding a patch and ball combo for shooting harder scrap lead.
And try tapered paper cartridges with hardened balls, cheap shooting. [fast reloads]
Love these big bore guns!
First thing needed is to round the sharp edge of the taper to bore on the muzzle.
and get the right ball and patch combination.
A .72 can be from .715 to .730 in bore size.
In my .73, I shoot a mild load of 125FF and a .725RB.
If you are going to hunt elk, you need to know about Tapered paper Cartridges!
8 second reloads are easy, not so much on the run, but you don't loose any powder!
http://rjrenner.blogspot.com/p/tapered-paper-cartridges.html
Lots of 'tapered wood' on ebay for mandrels.
And they work in a 54!
I double lunged an elk with 90 grains of 3F and a slightly hardened round ball. [could still scratch it with a thumb nail]
40 yards, clean thru with the 54.
My green mtn barrel shoots best with 90-95 grains of 3F with a .537 ball and tight pillow ticking.