I was doing some long line (600 yd) workups a couple of days ago. 23.5 grs of H4895, bullets seated at 2.380\” coal (single-load for the long line strings in xtc) and I got a 5-shot group that measured 1.38\” extreme spread at 100 yds. Keep in mind, the rifle (and barrel) is an off the shelf Windham 20\”, govt A2 profile barrel with a chrome-lined bore and chamber. I also got a 5-shot group from the same test with SMK 77\’s that also measured 1.38\” extreme spread. Same powder charge and coal. The results speak for themselves. I\’d post pics if I knew how, here.
For mag length I load them at 2.210\” coal and get similar results, same load. I\’m sure with a better barrel the groups could be improved upon.
Apparently MY barrel prefers extra long and extra short coals.
Hope this helps you some.

Jon