I have a mint Model 70 in 300H&H that I have had a long time, 50's vintage. I have shot it but between the original steel butt plate which is a killer and the collector value, I retired the rifle. Factory ammo isn't much better if at all to the hot 30-06 loads. With hand loads you can get similar velocities to the 300 Win Mag. Because of the long taper, case sizing to within .001-.002 of the rifle's headspace is important to get the accuracy out of it. I had no problem getting .5MOA with careful attention to my loads, as good as my 300WM. I think the primary reason it fell from favor is that when the 300 Win mag came out, it could be built with standard length actions. Also, the factory ammo was toned down because of the large number of older rifles in circulation.