Correct that's because the difference in the 38spl case length vs the 357 case length is .135"
The difference in the crimp grooves on the lyman 358156 bullet is +/-.090" depending on the cherry that cut the mold. I've had several different 358156 molds over the decades and have sold all of them off except for the 1 pictured above in my earlier post. I kept it because it was a special order mold. A standard lyman hp pin for the 35cal molds used a .125" hp pin. Back in the 70's or earlier you could special order a 35cal mold with the larger .156" hp pin. The .156" pin was the standard hp pin for lymans 44cal & 45cal molds. The mold I kept/use has the special order .156" hp pin.
Anyway old skeeter knew enough about case volume and seating depths that he did back the 2400 load off 1 full grain when using 38spl cases. Had to do with the .135" vs .090". If he would of left the oal's the same it wouldn't matter. I can only assume he didn't because he wanted to use a crimp in the crimp groove of the bullet.
There's something to be said for taper crimp dies & I absolutely have to get 1 of the new lee collet crimp dies to play with. I want to do head to head testing with roll crimps vs tape crimps vs collet crimps.
