I have a load that I like for my .30-06 with 58 grains of IMR 4350 behind a Hornady Interlock SP. I am having a problem finding IMR 4350 locally. What is the real difference between IMR, H4350 and Accurate 4350. I see in manuals where they call for different charges with these 3 powders. Are they similar in properties?

I have not used Accurate 4350 enough to comment, but I have experimented quite a bit with H4350 and IMR 4350. I found the H4350 to be more consistent and accurate out of my 30-06's. I have not found an 06 yet that did not like 57gr of H4350 behind a 165gr Hornady Interlock SBT or Sierra Gameking. Sorry I couldn't be more help.

I have used AA 4350 for years in my 30-06 loads. 54 grains under a 165 to 180 grain bullet gives all the accuracy that I can ask for.
I also use it in .416 Rigby.
Pete