"Very interestingly, if one takes the Hornady 500-grain .458 diameter solid bullet and compares the penetration that results from impact speeds varying from about 1500-fps to 2500-fps, one finds that the higher impact speeds produce the least penetration. When driven to about 1500-fps (as the 45-70 will do) one finds that such solids produce nearly 6-feet of penetration in wet newspapers. When the same bullet is driven to about 2100-fps (as is characteristic of the 458 Winchester Magnum) one finds that the penetration is reduced to about 4 to 4 and 1/2 feet. When one tests the same bullet at 2300-2400 fps (as is characteristic of the 458 Lott) one finds that the penetration comes up nearly 20% short of that produced by the 458 Winchester."
http://www.garrettcartridges.com/penetration.html
Garrett doesn't think it's bunk.
That is not a function of speed or energy... it is the result of the stability and design of that particular bullet... suggesting that MORE energy results in LESS penetration (all else being equal) is as assine as insisting that driving 60 km/hr will result in arriving at your destination more quickly than if you are travelling 100 km/hr.
If you want to discuss and compare depth of penetration there are many factors to table, simply stating that a slower bullet results in deeper penetration is faulty logic and misleading.
Laws of physics. The faster bullet transfer more energy faster than the slower one. Like slapping water. Go slow and your hand glides thru. Smack it fast and you meet more resistance...
You don't specify what bullet they are using for their tests. If it was a relatively soft point it probably expands considerably more at the extra velocity (probably no expansion at all at the slower velocity) which would produce more drag/quicker slow down.
Laws of physics. The faster bullet transfer more energy faster than the slower one. Like slapping water. Go slow and your hand glides thru. Smack it fast and you meet more resistance
Also I have tried this with 500 gr Winchester solids in both my 45/70 and 458 wm. 1280 fps vs 2200 fps. The 45/70 out penetrated my 458wm. Neither bullet showed signs of failure. Except for rifling marks both could be loaded again




























