There's no real data for ACME bullets.
I'm looking to load 38 Specials to shoot out of a Henry X 357/38 Lever Action and Ruger GP100. Possibly some older S&W 38's. I'm looking for a seating depth and maximum charge using Bullseye. Maximum charge as in "do not exceed"... I'm leaning toward 4.4gr of Bullseye, seating the 148gr BNWC-NLG HiTek Coated slug so the case mouth is in the middle of the crimping groove, the "button" would hang out from. 1.285"+/-. That'd be about the limit.
RCBS Cast Bullet Manual #1, page 145, #38-148-WC Bullseye 4.0-4.5 No COL (960 fps)
Speer #12, page 510 says: BB-WC Bullseye 3.9 to 4.5gr 1.295" COL (933 fps)
Lyman 3rd, Page 157 says 150gr #.58091 Bullseye 3.1 to 3.5 1.317" COL (942 fps)
Hornady 5th, page 660, 148gr #10108 BBWC 2.1 to 3.0gr 1.180" COL (750fps)
I have shot a number of the ACME 158gr RNFP out of the Henry X and accuracy is not as good as I would like. Shoots great in a pistol!!!
Will make separate thread for the ACME 125gr FP HiTek & 125gr RNFP HiTek slugs.
Here I have three mock-ups:
1.285", 1.300", 1.350"