45 Colt, MP 454640 + HP 38 Range Report

[pdgoutdoors]

I did some testing with my new MP 454640 CBs at the range yesterday with the Penta HP pins installed. The boolits weigh around 262gn with range scrap air cooled and PC'd. They are sized to .454 and loaded to an oal of 1.639, which puts the crimp right under the top of the crimp groove. All groups were shot on a rest at 15yd for pistol and 50yd for rifle (5 shot groups) and speeds measured with a LabRadar. Below are the results:

Marlin 1894 CB ltd, factory sights
5.9gr HP38: 848 fps avg, 24 SD, 1.6" group
6.2gr HP38: 894 fps avg, 11.6 SD, 2.69" group
6.5gr HP38: 919 fps avg, 15 SD, 1.4" group (not including the one I pulled)

Cimarron El Malo 2 (Pietta SAA Clone)
5.9gr HP38: 681 fps avg, 35 SD, 2.17" group
6.2gr HP38: 721 fps avg, 18 SD, 3.4" group
6.5gr HP38: 744 fps avg, 33 SD, 1.97" group

No leading to report. Barrels slug at .451" in the marlin and .453" in the Pietta.

[pdgoutdoors]

Sent from my iPhone using Tapatalk

[Kosh75287]

I don't want to upset progress, but can you safely increase above 6.5/W231/MP 454640? The groups appear to be tightening, as charge weights increase. I would EXPECT better accuracy to ensue as you approach "maximum".

[pdgoutdoors]

I don't want to upset progress, but can you safely increase above 6.5/W231/MP 454640? The groups appear to be tightening, as charge weights increase. I would EXPECT better accuracy to ensue as you approach "maximum".

Given there is no published load data for this projectile, I based my starting data off of the 270SAA data in the Lyman book. I did this because the weight is within 8 grains and the seating depth is only 6 thou less than what it recommends for that boolit. The max load for that in the book is 6.7, but I approached with caution given the unknowns. I would feel comfertable pushing over max slightly for my Marlin, but do not want to risk the pressure on the revolver. Plus, I am going more for a plinking load here instead of a hard hitter.

[Tall]

I recommend using Hercules / Alliant 2400 to achieve the best accuracy.