Leaves vs Bud

I've been cooking Cannabutter for over 3 years now And it seems like All my batches turn out different each time. I can understand that because up to about eight months ago all of my Bud were different strains from different stores, but since my harvest came in I've been using my own the last eight months or so. I always use 1 ounce of ground leaf or bud, my last batch was 1 ounce of ground Bud and the one before that was 1 ounce of ground leaf. I made twice as many brownies with the Bud thinking that it should be at least twice as strong, it wasn't, so now I'm confused if there is any real big difference between leaf and Bud. Anyone else have any unusual experiences like this?