Yeah, there's no reason to change if it ain't broke. But I didn't try IMR4451 with 165's in the .30-06 just to experiment. I tried it because my supply of H4350 was running low, and it was just about impossible to find. Could get IMR4350 but had become addicted to the H version, due to short-cut powders and consistent performance in cold weather. It worked great, so I started switching to IMR4451, because it's short-cut and cold-resistant--and am glad I did.
Something has been going on with supplies of H4350 over the past few years, aside from the "shortage" created by generally increased demand for shooting supplies. For the past year I've been able to buy IMR4350 pretty easily, along with many other powders that were scarce for a while, including the Ramshot rifle line.
But H4350 has been scarce or non-existent in stores and on websites for several years. Just checked the 5 websites where I buy most of my regular-use powders. NONE had any H4350, but ALL had IMR4451, so am glad to have made the change--and am continuing to switch to IMR4451 in other cartridges where H4350 had long been my go-to powder, such as the .243 Winchester, .257 Roberts and 7x57 Mauser. So far 4451 has worked just as well, if not a little better, in every application.
