12 gauge load confusion.

[L W Smith]

I just got my first BP shotgun, bought it off of this forum.
I'm looking for wads and cards to buy so I can feed it but I'm confused about what I should be getting.
It's marked as a 12g and the cards/wads I'm finding give a diameter of ~.740.
When I measured the bore of my barrels they both come out to .688. The claim was that one is supposed to be cyl and the other modified chokes but this seems like full or possible extra full chokes, if it is actually a 12g like the gun says.
My biggest question is, should I just go with 12g wads/cards and force them in, or should I get some that are 14g which are around .703? Or is there another size I should be looking at?

I just punch out cardboard wads and use a shot cup that holds 2.5 ozs copper coated # 4.been using this for years and harvested many turkeys with it out to around 40 yds...

 

[L W Smith]

I just punch out cardboard wads and use a shot cup that holds 2.5 ozs copper coated # 4.been using this for years and harvested many turkeys with it out to around 40 yds...

Oh and also cardboard over shot to hold shot in place...sorry