just fire some 303 rounds the brass will be fire formed and need a trimming
then I have loaded 10 grs of bullseye then a cardboard wad fill with shot of your choice and another card wth a bit of elmers glue to hold it in fun to shoot anf has some punch too
once you fire form just pop the primer no resizing needed ill put up some pics of mine tomorrow
i did somemore research and found out that the british 410 is actually a 2 inch shell not the 2.5 we have and unless there is some hidden milsurp it is not being made anymore. Also on the 303 part of it is all that is required is to shoot the bullet or do i need to do something to it to were when i shoot it it makes it a straight wll shell?
is there any other casings than the 303 and the 444 marlin that might work for making 2 inch 410 shells. my dad does have a lee enfield that shoots the 303 british but i am trying to find a cheaper casing than 303 cause 303 ammo is not cheap around here. nor are the casings
British .410 shotgun has a 2 inch chamber (mostly) whilst the US .410 Shotgun is longer at 2,5 and 3 Inches, (case length,) the body and head diameters being the same.
Indian .410 Musket ( a Riot and Police cartridge) is totally different. it is based on the .303 case head (actually a .303 case in production, tapered only to take a .41 cal. ball or shot.)
The head diameter of the .303 is .455-7, the head diameter of the .410 Shotshell is .475 or bigger. The two will Not interchange.
When the .410 Ishapore Muskets(Smoothbore SMLE) were imported to the US, many had their chambers reamed out to .410/3 inch, to accomodate US Ammo supplies.
This vandalism, whilst typical of US Importer greed has left precious few .410 Muskets still in original calibre.
To make original "Cartridge, .410 Musket", take a .303 case, and fire-form it to the Original chamber, then load up as if loading a shotshell.
As to the use of .444 Marlin cases, these will work ONLY in a Rechambered (ie, vandalised) Ishapore. The Marlin case makes an excellent 2 inch .410 shotshell of standfard dimensions.
It(the Marlin) will NOT fit an original .410 Musket chamber.