Been loading the h&g #50's and the lyman 358495 & 358395 bullets long for decades (since the 80's) crimped in the middle lube groove using 38spl cases to use in the 357's.
Started pc'ing bullets in 2014, took this picture of the h&g #50's in 38spl cases before 2014. Used to lube the bottom 2 lube grooves only.
Post 2014 with the same h&g #50 that has been pc'd loaded in 38spl cases next to it is a mihec 640 158gr fn hp. The 640 has 2 crimp grooves just like the lyman 358156 bullet & is crimped long in the bottom lube groove in 38spl cases.
6-shot groups @ 50ft with those loads pictured above shot in a s&w 686
Testing 220gr hbwc's in a s&w 624/44spl. The 220gr hbwc is seated flush, crimped in top lube groove, crimped in the bottom lube groove and seated backwards making a huge hp. I also test lube in 1 groove, 2 grooves, tumble lubes, etc.
Moving the bullet out further in the case is putting the shoulder of the bullet in the leade of the cylinders. This aids in alignment and increases accuracy. The top bullet is seated to the standard "book" oal. The bottom bullet is seated long putting the bullets body into the leade of the cylinder.
I never hurts to test different oal's. I cast my own bullets and pretty much have an unlimited supply of free lead so it no big deal to burn 700/800 bullets playing around with oal's, diameters, lubes, etc. Looking for a combo that puts bug holes in paper.