12gauge BP question. Brass shells and load.

[mrcrossbow]

Good afternoon. A question or two I need help with.
First let's start with what I have.

-single shot shotgun ( break action) mod choke. Have shot a few challenger slugs though it so I'm fairly sure the action is strong enough for a decent BP load.
-Brass. Magtech 12 gauge
-Goex ffg
-buck shot. 00
-10 gauge over powder card and fiber wads ( in mail coming)
-11 gauge over shot card
-Cci large pistol primers

Iv googled the hell out this and there is some CAS load stuff and some other questionable load stuff.
I'm looking for fully functional loads ie hunting, my hunting loads are my target/practice loads as I like to practice with what I'll hunt with.
From what iv seen on google loads range from 35grains to 150 grains, a average being 65 ish for cas.
Was a few that are at 80 grains and that seems right maybe, I'm honestly not sure.
Also some how in my excitement to get new stuff I forgot BP powder measure. I'm open to any house hold items that will work. I have some 45-70 emptys but no idea how much a full case of BP would be,
Any ways I'm looking for a decent hunting load with buckshot and a item I could use as a measure.
God this got long winded sorry folks.
Oh please feel free to inbox me load data if don't want to post. Any help be great.