ColColt
05-13-2011, 12:56 PM
I just got back from the range with the M29-3 and was surprised at the groups despite the fact the 250 gr boolits weren't the exact throat diameter. I had made about 100 from a mix of BHN12 alloy and the only sizer I had would only bring them to .430" and the throat diameter is .432".
Still-looks like I need to beagle the mold and I've ordered the largest sizer Lyman has which is a .431". In another thread someone made a recommendation of not only beagling the mold but lapping the die. I may need to indeed do both. The surprise came when the groups I had were averaging 1 1/2" at 10-15 yards. This was a conglomerate of 11 gr of HS-6, 10 gr of Unique and 8 gr of Universal and of course I had to load up about 10 20 gr of 2400 which gave an 1 1/4" group at ten yards. All these were from the 429421 mold which drops them at on average, 248 gr.
Oddly enough, the leading I got was primarily just into the grooves about 1/2" past the forcing cone. Another surprise came when my last string was with the 20 gr of 2400 load with the same bullet. It actually seemed to clean up the small amount of leading at the area just into the rifling but did show small traces of leading toward the muzzle instead. Perhaps that clean up was due to it sealing the bore better...just a guess. None of this leading was great and a few swipes with Hoppe's followed by a brush cleaned it up without Chore Boy.
I still think I should more closely get the sized boolit to the throat diameter of .432" despite the small amount of leading and the great grouping.
Still-looks like I need to beagle the mold and I've ordered the largest sizer Lyman has which is a .431". In another thread someone made a recommendation of not only beagling the mold but lapping the die. I may need to indeed do both. The surprise came when the groups I had were averaging 1 1/2" at 10-15 yards. This was a conglomerate of 11 gr of HS-6, 10 gr of Unique and 8 gr of Universal and of course I had to load up about 10 20 gr of 2400 which gave an 1 1/4" group at ten yards. All these were from the 429421 mold which drops them at on average, 248 gr.
Oddly enough, the leading I got was primarily just into the grooves about 1/2" past the forcing cone. Another surprise came when my last string was with the 20 gr of 2400 load with the same bullet. It actually seemed to clean up the small amount of leading at the area just into the rifling but did show small traces of leading toward the muzzle instead. Perhaps that clean up was due to it sealing the bore better...just a guess. None of this leading was great and a few swipes with Hoppe's followed by a brush cleaned it up without Chore Boy.
I still think I should more closely get the sized boolit to the throat diameter of .432" despite the small amount of leading and the great grouping.