Post by bradshaw on Feb 11, 2018 13:53:05 GMT -5
277 gr Volcano left, 300 gr LBT WFN right:
*****
Dan.... for whatever reason, this particular .452” 300 grain WFN GC cast from an LBT mold is out of round on the nose end, as measured by Lee Martin. That had not been determined when, based on the idea that Center or Gravity may be coincident or very close to Center of Form, I suggested to Lee that a hollow point should push CoG rearward, thus improve dynamic stability. Upon sending Lee these bullets, he measured the bullets and discovered eccentric forward mass. The first batch Lee drilled shot fantastic from the Ruger 03. Neither Lee nor I have wrapped our skulls around why I got an astounding accuracy improvement, yet could not repeat it or come close on a subsequent batch. My shooting on the accurate batch included:
Ruger 03 .45 Colt, five consecutive shots
Shot #1----25 yards
Shot #2----75 yards
Shots # 3, 4, 5----100 yards, 3x3=1.9”
My though was that Lee had managed to remove whatever imbalance plagued the nose while separating CoG from CoF.
We decided ultimately the mold just wasn’t to be saved. To continue that experiment, we should start with a fresh mold, shoot it 100 yards, then repeat the shooting with a Volcano or hollow point variant. If one or both bullets prints tight, group again @ 150 and 200 yards.
With your own experiment, varying meplat width, whether it is time to try a gas check, or otherwise eliminate taper or step at the heal. Is the 75% meplat,----which produced the tightest average, 2.8” @ 100 yards----the only bullet of the group with a square heal?
David Bradshaw
*****
Dan.... for whatever reason, this particular .452” 300 grain WFN GC cast from an LBT mold is out of round on the nose end, as measured by Lee Martin. That had not been determined when, based on the idea that Center or Gravity may be coincident or very close to Center of Form, I suggested to Lee that a hollow point should push CoG rearward, thus improve dynamic stability. Upon sending Lee these bullets, he measured the bullets and discovered eccentric forward mass. The first batch Lee drilled shot fantastic from the Ruger 03. Neither Lee nor I have wrapped our skulls around why I got an astounding accuracy improvement, yet could not repeat it or come close on a subsequent batch. My shooting on the accurate batch included:
Ruger 03 .45 Colt, five consecutive shots
Shot #1----25 yards
Shot #2----75 yards
Shots # 3, 4, 5----100 yards, 3x3=1.9”
My though was that Lee had managed to remove whatever imbalance plagued the nose while separating CoG from CoF.
We decided ultimately the mold just wasn’t to be saved. To continue that experiment, we should start with a fresh mold, shoot it 100 yards, then repeat the shooting with a Volcano or hollow point variant. If one or both bullets prints tight, group again @ 150 and 200 yards.
With your own experiment, varying meplat width, whether it is time to try a gas check, or otherwise eliminate taper or step at the heal. Is the 75% meplat,----which produced the tightest average, 2.8” @ 100 yards----the only bullet of the group with a square heal?
David Bradshaw