"Flat" shooting 45 Colt recipe for Marlin Cowboy?

Evening, some loading manuals have a separate section of 45 Colt loads for Ruger Blackhawk SA revolver and Thompson/Center Contender break-action single shot pistols. Would you say the action in the Marlin Cowboy is as strong or stronger than that of these other 2 weapons?

I've made up some easy going cowboy loads (5.5-6.5 grains Unique / 200 gr. LRNFP) to get things started with my new rifle. I have tried them and the rifle is a great pleasure to shoot. Today a friend loaned me a scope to try with it which I've already mounted so now I'm looking to load something that'll shoot flatter. Maybe mentioning flat shooting in the same sentence as 45 Colt ain't a good go together. I'd like to do some 50 and 100 yd. target shooting. I have 4 or 5 manuals, but I'd like to draw on the experience of some of you experts here. If you'd like to share a recipe you think I'd have a little fun with at these ranges or maybe just a good load to start working up from, I'd sure appreciate it. I'll be glad to answer back as to how they shot. Thanks.

J.

since you mentioned unique as a powder i'll assume it is the one you want to work with.
a few things to think about first.
are these commercial cast boolits?
does the boolit carry enough quality lube for the increase in pressure and velocity?
the marlin is made in which other calibers? 44 mag i'll assume. the marlin is a strong action but not as strong as the rugers or even the 92's are.
but you can certainly exceed the 14k loads.
i'd work up the unique to an acceptable accuracy level for you.
start at 7 grs which will leave a scorch mark on the case still and move ahead.
to 8 then 9 and possibly 10 grs.
if you want more velocity you can start at 17.5 grs of 2400 and move up from there.
19-20 is usually a good load in the 45 with 200-250 gr cast boolits.

Morning, thanks for chiming in. I've given some thought to using 45/325gr. LFNPB .452 dia. from Cast Performance Bullets if they've got'em in stock.
Might use H-110 21-23 grains. I need to do a lot more research on it for sure.

I have 2400 and Unique. I've used some Trail Boss too for cowboy loads. I'm just getting my feet wet this Marlin which is a new rifle. Sure have enjoyed the little bit of loading and shooting I've done for/with it.
Thanks, J.