Re: Can't find H4350. In stock alternative?
IMHO: Nothing is going to work as well in 6.5 (-08, CM, L) as H4350.
In my 'worry' over the current 'shortage' I may get a jug of IMR4350, before doing that I am trying some other powders for my 6.5-08 (260 rem) and non-belted magnums. H4831 and H1000. Pretty slow but I'm chucking some big projectiles. There are other powders that are not 'expected' for loading 223 and 308 that will work and are in stock and most places.
I've got IMR7828 (reg and SSC) for those nice shinny, long belted magnums. Those could work in my non-belted and 260 as well.
Interesting note: With IMR4350, H4831, H1000 and IMR7828 it appears that I can't 'blow my self up' because they pretty much all go to compression before max PSI. Of course this is from the books/websites and each rifle is different so as always, I will start low and work up. If they 'work' then I have an alternative.
There is also "Superfromance". The published loads are all for lighter projectiles but you can call and ask if they have guidelines.