Percussion v Flintlock powder charge

[Pinguino]

So how come the exact same gun - a Pedersoli Le Page .44 has different manufacturer powder charge suggestions depending on whether it has a percussion or flintlock firing mechanism?

The owner manual states that a Le Page .44 percussion model should use 18 grs, but the Le Page .44 flintlock should be loaded with 24 grs. BOTH are rifled barrels so it's not because one is rifled and one is smooth bore.

Looking at the Pedersoli charge loading charts for their firearms - the flintlocks are all shown with greater loads.

Can anyone explain this please?

[kennyc]

I'm going to guess here, is there more pressure loss through the open touch hole of a flintlock v the closed nipple of a percussion arm ?

[ovenpaa]

Despite being 'exact the same', could it be down to a heavier barrel maybe or the internal ballistics based on the ignition method?

[dromia]

Greater gas loss in the flintlock through the touch hole than through a nipple.

[Pinguino]

So almost a third more powder to allow for pressure loss through pin hole!! Thanks for the info gentlemen.

[dromia]

It is not just the pressure loss, with the larger touch hole the pressure under which the powder ignites will be less therefore making for a less efficient burn in the barrel so less pressure due to that as well as the loss through the touch hole.