Maven
06-18-2014, 11:12 AM
Several weeks ago I asked about the CB's mentioned in the header and received samples of each from Airman Basic and 2wheelDuke: http://castboolits.gunloads.com/showthread.php?244218-Any-experience-with-Lee-358-140-SWC-or-TL-358-158SWC-in-S-amp-W-Model-10 I fired those two designs @ 25 yds. against a known load and CB, namely 3.1grs. Hodgdon Clays (original formulation) and the RCBS 148gr. WC (seated backwards, i.e., with the button nose toward the powder). All CB's were sized to .358" and roll crimped. Although I have the targets, I cannot upload pix of them from my camera to my 'puter [as the original software has been corrupted and I no longer have that disk to reload it]. Until I get that sorted out, I'll have to describe the results.
Lee 140gr. SWC, 25 shots These shot OK, but the vertical dispersion on the target 8.5". Indeed, I couldn't keep 16 of them in a 3" square that I use as a target (3" x 3" set at 45 deg. wi. a 3/8" black border). However, I wonder if seating them deeply and crimping over the front driving band as Back Assward suggested, would have improved things?*
Lee 158gr. SWC, 50 shots, with 25 powder coated These gave almost half the vertical dispersion of the lighter CB and grouped very tightly in spite of the open sights and my almost 70 yr. old eyes. In fact, the positive comments about this CB (6) were indeed justified. The 140gr. SWC received only 3, btw. The 25 powder coated CB's grouped well, but impacted the target higher and to the right. This CB and my Mod. 10 seem to be a such good match for one another that I'll be looking for a Lee 6 cav. mold for it very soon.
Leading Minimal, easily removed, and mostly at the forcing cone: not enough to affect accuracy as the 50 158gr. SWC's were fired 2nd and grouped quite well.
*The first 5 RCBS WC's were seated slightly (~1/16") below the case mouth and roll crimped. Three were touching while the others were close by. The 25 remaining WC, though seated backwards, were roll crimped in the first (nearest the base) lube groove (nearest the base). Based on those results, I think the accuracy 40gr. SWC would markedly be improved if seated similarly.
Lee 140gr. SWC, 25 shots These shot OK, but the vertical dispersion on the target 8.5". Indeed, I couldn't keep 16 of them in a 3" square that I use as a target (3" x 3" set at 45 deg. wi. a 3/8" black border). However, I wonder if seating them deeply and crimping over the front driving band as Back Assward suggested, would have improved things?*
Lee 158gr. SWC, 50 shots, with 25 powder coated These gave almost half the vertical dispersion of the lighter CB and grouped very tightly in spite of the open sights and my almost 70 yr. old eyes. In fact, the positive comments about this CB (6) were indeed justified. The 140gr. SWC received only 3, btw. The 25 powder coated CB's grouped well, but impacted the target higher and to the right. This CB and my Mod. 10 seem to be a such good match for one another that I'll be looking for a Lee 6 cav. mold for it very soon.
Leading Minimal, easily removed, and mostly at the forcing cone: not enough to affect accuracy as the 50 158gr. SWC's were fired 2nd and grouped quite well.
*The first 5 RCBS WC's were seated slightly (~1/16") below the case mouth and roll crimped. Three were touching while the others were close by. The 25 remaining WC, though seated backwards, were roll crimped in the first (nearest the base) lube groove (nearest the base). Based on those results, I think the accuracy 40gr. SWC would markedly be improved if seated similarly.