i have noticed that the primer flash hole in a shotgun shell is substantially larger than the flash hole in the 209 holder in a muzzle loader. i have not measured them, but a guy who i consider very much up to speed on these topics told me that the typical flash hole is ~0.030". i also notice a lot of soot is apparent when using the 209 primer. a lot more than i imagined there would be.

2 questions:

1. is there some particular reason why the muzzleloader restricts the flame and the shotgun shell does not?

2. if the hole was larger, would that allow more of the fire to go into the barrel and lessen the sooting situation?

thanks for the help.

Good question! I wish someone would answer this. Were you thinking about drilling out the breech plug?

The small hole restricts pressure and flame from both directions; when the primer ignites and also when the powder ignites. Alot more pressure and flame in the second ignition!

Remember that shotgun shells have the primer pressed in and muzzle loaders just have them set in.

God Bless, Louis

The smaller hole is to lessen the fouling released into the action.Older sidelock guns would get the hammer blown back to full cock sometimes with heavy loads ,through the nipple with a lot smaller hole than .030".

On inline style guns the hole is made small to keep the powder from going strait through the action before the primer is put in place. The hole can be oppened up but not any bigger than the granulet size of your powder.