[41thunder]

Originally Posted by lclund1946

I am sorry but I think what SC said was that Bullets with the same, or similar, SD will penetrate the same at the Minimum Impact Velocity. Of course the bullets have to be of Similar Construction but not the same weight or diameter. The SD, or Sectional Density, actually represents the weight of a cross section (lbs.per square inch) so is if it is the same it is the same regardless of the size of the bullets. This is why industry have adopted SC's method of calculating Effective Range using SD above 0.25 for Heavy game and below 0.25 for light game. Minimum Impact Velocity, as determined by industry for a particular bullet design, takes into consideration how it is expected to expand and the minimum Velocity X SD take energy into consideration. Noslers LRAB bullets have a Minimum IV of 1300f/s which makes them good for expansion at the range that velocity is achieved but at 3300 fps just ahead of the muzzle it may well come apart and not penetrate well at all. The 26 Nosler has a lot more ME and Recoil at 3300 fps with the 129 LRAB but actually has 1200 ft. lbs. energy at 745 yards which is just the same as the 6.5 PRC with the 143 ELDX. While it doesn't reach its minimum IV until 1350 yards it only has 486 ft.lbs energy left which may not be enough to penetrate through past the hide and a rib. By this we can determine that the 6.5 PRC would be equal on Elk to 754 yards with these two factory rounds and likely the 6.5PRC would be more effective at 100 yards. The 300 Win Mag with the 212 ELD-X factory load would reach IV at 820 yards and the excess energy would leave a more devastating wound channel at 1530 ft. lbs. TE but the Elk would not be any more dead as penetration would be about equal if shot through the lungs. That extra energy would then be considered Excessive or Wasted or as some say overkill. Using a 180 grain Win PPP in the 300 Win Mag would put the 1200 ft. lb. TE at 660 yard Effective Range and 1739 fps IV so it comes in last and would kill the ELK with less wound trauma than both the 26 Nosler and 6.5 PRC at 745 yards. I did not manipulate the figures but punched in different scenarios give a good indication how different Cartridges and ammunition compare as to Effective Range. Of course the 300 Win Mag will produce more damage with the excessive energy with 212 bullets, as would the 26 Nosler loaded with the 142 LRAB, at 750 yards but is excessive meat damage all that desirable. The True Magnum people used 750 yards maximum on Elk, with factory ammo, and Moderate Recoil as the criteria for selecting the cartridge for their clubs rifle and the 6.5 PRC was the winner.

You do know they also sell it in 338 300 and 7mm