phigaro4570
10-19-2013, 11:51 PM
Recently I lapped my .44-250-K rear driving band to try to remedy the leading I was getting in the cylinder and forcing cone. I have never heard the middle and front bands mentioned much, but I have come to believe that, before the rear band makes it to the cylinder throat to seal there, gasses shoot past the mid-band before it gets to the throat. So, I lapped the mid-band out another .001" and, now paranoia is creeping in and I really wish the front band were .432" as well. At least it would be doable on the RCBS, but my Lyman 358429 has a front band that is around .004" small. I haven't yet tried shooting since the mid-band is larger, and don't know if I will end up wanting the front one larger, too. (That one would really caulk the hole quickly.)
Perhaps I don't see these bands mentioned specifically because people are enlarging or beagling the whole cavity uniformly. I drove a 5/32" Allen wrench in the same sized hole and got enlargement only on the rear most piece of linotype bullet I was using. Has anyone else pursued this same trail with a SWC and leading? I guess you'd encounter this same problem relying on obduration since it would presumably affect only the rear band.
Thanks,
Phigaro4570
Perhaps I don't see these bands mentioned specifically because people are enlarging or beagling the whole cavity uniformly. I drove a 5/32" Allen wrench in the same sized hole and got enlargement only on the rear most piece of linotype bullet I was using. Has anyone else pursued this same trail with a SWC and leading? I guess you'd encounter this same problem relying on obduration since it would presumably affect only the rear band.
Thanks,
Phigaro4570