Tino, you will find a lot of information relating to your question a few threads down on this same section of the Forum. See "Could the Pedersoli .72 double be successful on buffalo".

I just did some checking on the new Gibbs .72 Safari Rifle. The Dixie Gun Works catalog always has full information on such guns, including recommended load, rifling depth, twist rate, etc. Unfortunately, I did not find this rifle in the 2009 catalog. So a look at Pedersoli's website (www.davidepedersoli.com) gave a good bit of information.

This rifle uses the same barrel as the Pedersoli .72 double rifle I mentioned above. The barrel is a little longer at 29". Twist is the same at 1 turn in 75 inches, so the 1:86 twist rate in the other thread is in error. Both guns use a .715 round ball of 545 grains (as I recall). Some people have reported it is very hard to load when cast of wheel weights for hardness. This is because a lead alloy like WWs casts a somewhat lighter ball that is larger diameter than one of pure lead. Probably a mold meant to create .710 lead balls would cast about right to provide a .715 hard ball made of WWs. Others may know the size mould to order exactly.

The .72 double rifle weighs 10 1/3 pounds whereas the new Gibbs .72 weighs just 9 1/4 pound. It has the classic look of an English Sporting Rifle of the 1860-1880 period, which is ruined by putting modern looking sights on it. Or so it appears in the rather small picture at the website.

Pedersoli must have a bunch of Italian lawyers advising the loads for their guns, which are always LOW. They make their own high quality broached-rifling barrels as far as I know, and certainly must know that buyers are not going to shoot such a rifle at large game with some shotgun load like 80 gr. of B.P.

Having a Pedersoli Mortimer with custom .54 barrel myself and shooting it with 120 gr. 2F B.P. and a 585 gr. bullet gives quite a bit of recoil I assure you. It weighs 9.5 pounds, so a 4 dram load (110 gr.) of BP and the approximately 530 gr hard ball in the .72 Gibbs weighing 9 1/4 pounds would certainly provide similar recoil. I am not vouching for that load, just proposing it is likely one that would be used by some people.

You will get even better velocity in the .72 Gibb's 29" barrel than the .72 double rifle, so it should do well with even dangerous game - as described on the other thread. The key is to use hard balls.

Aloha, Ka'imiloa