Looking for the best performance for casting a heavy arrow - 800-900 grains out of a 72-75lb bow @ 30in. Looking at a R/D longbow, or a recurve. Know a ton depends on specific design. Primarily looking at Sarrels & Ramparts (primarily rampart as I've been looking for an excuse to get one for a while). Just curious if you were looking for the best performance with arrow weights in that range which way you'd be focusing??

Whichever throws the arrow faster.  Used to be an easy answer...the recurve would be the more efficient.  These days a decent R/D can come close to or even exceed the performance of a recurve.  

You can look at performance at a lower arrow weight as a guide.  The difference between the two may change slightly as arrow weight goes up, but it won't be by very much.

I can't speak to either of those two makers, but I have an 80lb Harrison HSS that wails 910 grain arrows out of it.

My experience has been that speed may sometimes come with a compromise in manners. Harrisons tend to be quiet, well mannered, and surprisingly easy to tune while providing a flat trajectory with heavy arrows.

Why do you need to have THE most efficient bow? I've successfully used heavy weights of both styles, and guys like Negley, Hill and Swinehart worked wonders with both. Most any bow will do a fine job, so my recommendation is to go for one you really like, knowing that it'll perform with excellence.

Okay, for longer shots, one bow might have a flatter trajectory than another. But I'd be inclined to stick with closer shots.

I know I'm biased, but the Pittsley Predator will please you in all of the ways you mentioned, among others. But the Predator would be my first choice in a shoot-able, high performance bow.

Narrowed down to the 2, I'd opt for an r/d lb at 66" or 68". Whichever would build to my handle preference. That's a lot of arrow. Must be elk or moose there in Colo.

Have you shot both Bows. If not I would Go with the Rampart, John builds a great three piece Bow, that performs awesome. Can not go wrong with either Bowyer, they both do great work. Good Luck

From what I am reading. Is there not an advantage in either style bow to shoot a heavy arrow?  I thought the heavy arrow is where the longbow shined. More working limbs?

in terms of efficiency of stick bow with regards to performance/speed, typically the hierarchy follows this suit - recurve, aggressive r/d longbow, mild r/d longbow, straight (hill style) longbow.  

also, typically as performance/speed increases, 'stability' decreases.

none of the above has anything to do with 'heavy bow, heavy arrow' - that's not the correct way to consider either bows or arrows.

What Rob said. It's all about design and efficiency when it's performance your after. Otherwise just find a bow you shoot well and go with it!

Thanks y'all. I like both bows, just haven't shot either in those weights. Gotten close on the ramparts, but neither make a bunch of bows that heavy. I'm not sure Bob would even try to shoot one that heavy.

I have both a sarrels 3 piece LB & Recurve, and both are great bows - but both are in the mid 50's @ my draw. Just not sure how that extrapolates to higher weight.

Hill, Black Widow and Schafer Silvertip are all GOOD at making heavy bows, and they do make a fair number of them.