Maven
10-14-2013, 04:30 PM
84308Several weeks ago, Ben posted how he converted a Lee Precision C (for gas check) -309-113 mold to plain base. Not only did he do a beautiful job, but the "new" CB's were very accurate as well. As I have two of those molds ("soupcans" as Buckshot termed them) that I seldom use, I asked whether he would remove the GC shank from mine too. His answer was simple: Why not try a sample before making an irrevocable change to the molds? Ben then sent me a goodly number of those soupcans, sized to .311", lubed, and ready to go.
Last week I got the chance to load 50 of them + 1 fouler for my .30-06 (Win. Mod. 70 Westerner + 4 x 16 Tasco scope). Although I've loaded many PBCB's, I never had one as light as [C]-309-113 before. (I'm guessing they weigh ~116grs. wi. lube.) Choosing a powder took a bit of thought: Blue Dot would probably work, but it would also be dirty, given the small doses the light CB would need. I ruled out Unique for similar reasons. My last choice was Hodgdon's Clays, which works well with lighter CB's and is fairly clean burning. Today I got to test the wisdom of that choice.
For my testing, I used mostly 1x fired Rem. brass, FL sized, trimmed (to 2.485"), M-die'd with primer pockets uniformed. Primers wer CCI #34's. All CB's were seated via a CH-4D Vickerman type die. As I mentioned earlier, I used Clays, which I some experience with when using 140gr. PBCB's, specifically Lee's 30-150-TL (MY mold casts light, 140gr.), but somehow knew that 7.5gr. would be excessive for a ~116gr. PBCB. I therefore chose to start low and work up: 4.4/4.5gr., 5.0gr., 5.5gr., 6.0gr. 6.5gr. All charges were thrown from a Lyman pistol powder measure using different rotors of known accuracy and reliability. The picture to follow has that data + measured group sizes, which I'll describe in a moment. I have to say, that with the exception of the 6.5gr. load, the other [4] loads produced 1 flyer, usually after I dry patched the bore after each 10-shot string to check for leading. Btw, the distance was 50 yds.
Top left bull = 4.4gr. Clays: 11 shots in a 3/16" x 1 13/16" group excluding the flyer
Top right bull = 5.0gr. Clays: 10 shots in a 1/8" x 1 5/8" group excluding the flyer
Midddle bull = 5.5gr. Clays: 10 shots in a 1/16" x 2 7/8" group excluding the flyer
Bottom left bull = 6.0gr. Clays: 10 shots in a 1/8" x 1 5/16" excluding the flyer
Bottom right bull = 6.5gr. Clays: 10 shots in 1/8" x 1 5/8", NO flyer
The 6.5gr. load was the surprise, as it was the only one which leaded the bore, but only a tiny bit and only at the muzzle. Each 1/2gr. increment raised the point of impact so that by the time I shot the last (bottom right) target, I was aiming ~1/4" lower than I was for the 4.4gr. load. What I was looking accuracy, i.e., whether or not the shots touched and how many touched each other. The flyers were merely an annoyance. Given that criterion, I think I need to retest all but the 5.5gr. load. I'm thinking the 4.4gr. load's dispersion may have been my fault as it's the first one I tested, and I often need to settle in when shooting.
Lastly, I have to thank Ben for his generosity in providing me with a goodly number of altered soupcans to test. I certainly couldn't have done this without his encouragement.
Last week I got the chance to load 50 of them + 1 fouler for my .30-06 (Win. Mod. 70 Westerner + 4 x 16 Tasco scope). Although I've loaded many PBCB's, I never had one as light as [C]-309-113 before. (I'm guessing they weigh ~116grs. wi. lube.) Choosing a powder took a bit of thought: Blue Dot would probably work, but it would also be dirty, given the small doses the light CB would need. I ruled out Unique for similar reasons. My last choice was Hodgdon's Clays, which works well with lighter CB's and is fairly clean burning. Today I got to test the wisdom of that choice.
For my testing, I used mostly 1x fired Rem. brass, FL sized, trimmed (to 2.485"), M-die'd with primer pockets uniformed. Primers wer CCI #34's. All CB's were seated via a CH-4D Vickerman type die. As I mentioned earlier, I used Clays, which I some experience with when using 140gr. PBCB's, specifically Lee's 30-150-TL (MY mold casts light, 140gr.), but somehow knew that 7.5gr. would be excessive for a ~116gr. PBCB. I therefore chose to start low and work up: 4.4/4.5gr., 5.0gr., 5.5gr., 6.0gr. 6.5gr. All charges were thrown from a Lyman pistol powder measure using different rotors of known accuracy and reliability. The picture to follow has that data + measured group sizes, which I'll describe in a moment. I have to say, that with the exception of the 6.5gr. load, the other [4] loads produced 1 flyer, usually after I dry patched the bore after each 10-shot string to check for leading. Btw, the distance was 50 yds.
Top left bull = 4.4gr. Clays: 11 shots in a 3/16" x 1 13/16" group excluding the flyer
Top right bull = 5.0gr. Clays: 10 shots in a 1/8" x 1 5/8" group excluding the flyer
Midddle bull = 5.5gr. Clays: 10 shots in a 1/16" x 2 7/8" group excluding the flyer
Bottom left bull = 6.0gr. Clays: 10 shots in a 1/8" x 1 5/16" excluding the flyer
Bottom right bull = 6.5gr. Clays: 10 shots in 1/8" x 1 5/8", NO flyer
The 6.5gr. load was the surprise, as it was the only one which leaded the bore, but only a tiny bit and only at the muzzle. Each 1/2gr. increment raised the point of impact so that by the time I shot the last (bottom right) target, I was aiming ~1/4" lower than I was for the 4.4gr. load. What I was looking accuracy, i.e., whether or not the shots touched and how many touched each other. The flyers were merely an annoyance. Given that criterion, I think I need to retest all but the 5.5gr. load. I'm thinking the 4.4gr. load's dispersion may have been my fault as it's the first one I tested, and I often need to settle in when shooting.
Lastly, I have to thank Ben for his generosity in providing me with a goodly number of altered soupcans to test. I certainly couldn't have done this without his encouragement.