Thread: 500 BPE load advice

Advice wanted from anyone actually using a 500 BPE or 500/450 BPE or experienced with something similar like a 50-120 or 50-140 Sharps ?
Or knows someone reliable who has the same and shoots it regularly

I'm nearly ready to let rip with the Hollis Martini 500 3" BPE
Will be sizing my 450 grain .515 down to .510 which will give me around 2 thou tightness in my Henry Rifled barrel.

I have a FFFG on hand as a starting point and Triple 7.
But might need to get some FFG

Should I make a card punch and make up some grease / card cookies ?
Light BP load and dacron under the grease card cookies ?
Do I need card and grease cookies at all if I use a well groove lubed projectile ?
Dacron to keep the reduced black powder loads agains't the primer ?

I'm reluctant to use trailboss with this huge case because I have been advised that the usual 70% might not apply to such a big long case !

As this cartridge was developed during the 1860s my expectations are very modest.
I will initially be happy to get the 450s safely out of the barrel at above the speed of sound.
Secondly if I can get the 450s safely doing around 1500 fps I will be delighted.
And thirdly if I can get it to shoot minute of small bard door I will be ecstatic