......I remember when I was a young man I heard the old O'Connor tale that there was little difference between a .300 H & H and and 06..I mentioned this to one of my older pals...He was a Camp Perry shooter and one of the two best rifle shots I have known in well over 50 years of shooting...he told me there is quite a bite of difference between the two..as I found out later..This is one old caliber that is enjoyable to own and use..and not everyone has one...
This is one of the rare things O'Connor wrote that I could never reconcile....apparently he came to the conclusion that the 300H&H was not any better than a 30/06 because th early ammo for the cartridge was designed as a "tropical load",meant to provide 30/06 ballistics in tropical heat with lower pressures.I guess this avoided mechanical difficulties under tropical condiitons with the powders of the day.
In addition,he lopped the barrel off is M70 behind the front sight (he did not like long barrels much),and his loads with 180's gave pretty anemic velocities.
I've owned and shot several,all pre 64 M70's,and at various times have had a H&H, 300 Weatherby, and 300 Win mag (both standard chamber and long throated),and while the Winchester and Weatherby both went a bit faster, the H&H was so close that any practical differences would be barely noticed..plus, as JB points out the H&H kicks more agreeably.
When the 300 WSM came out, I did some load work for it and was surprised when my charges of RL22 with the 165 gr bullet ended up at 72 gr;exactly the same as what I was using for the 300H&H and for the same velocity.Like Mule Deer says, they are peas in a pod.
As for "efficiency",the lowest velocity spreads I recall ever seeing coincidentally occurred the same day with a 300H&H and a 375H&H,and the 300H&H only showed 7-8 fps over a 10 shot string. It isn't any accident that the cartridge is known for its' LR accuracy despite the belt and antiquated case shape.The Brits knew what they were doing when they invented it.
I took one of mine to Canada to hunt deer and moose....only one older hunter even knew what it was;offers to the young guides to shoot my ammo in their 300 Weatherby's was declined.They thought I was nuts.
