You are spot on with your seating depth by comparing the bullet shank depth.
I used to swap bullets (lyman 358477/hg#50) & use the same powder charge. The crimp groove on the 358477 & the 1st lube groove on the hg#50 (wc) have the same bullet shank/seating depth. The bullets weighted the same, seated to the same depth, had excellent accuracy with the same loads, had the same poa.
The 44spl is an animal unto itself, there’s not a lot of data out there. I’ve shot 1000’s of wc & hbwc’s in the 44spl. I used a lyman 429348 wc for years & finely sold it & bought a Mihec 220g hbwc mold for the 44spl/mag. I always used the data for the light 200g target loads for the 45acp when I loaded/tested any wc/hbwc loads for the 44spl.
Any of these starting loads will work
Bullseye= 3.6g
231=4.0g
Unique=4.2g
If I was a gambling man I would bet that you’ll end up with the magic #5=5g of any 1 of those powders with that 204wc seated in the 1st lube groove. Just for the heck of it you should ask how many people use 5g of bullseye, unique or 231 for their pet 45acp load.
A link to a bunch of different 44spl loads, history & uses over the decades.
Index of /44_Special_Articles
The 38wc/hbwc you should have no trouble finding data for.
Some 38spl sd bullets that I make/use/shoot. A lead hbwc, a jacketed hbwc & a segmented jacketed hp that needs tested.
Some 44spl sd bullets that I make/use/shoot. A lead hbwc, a jacketed hbwc & a segmented jacketed hp that needs tested.