For me and my gun, that has not been the case. I did look else where, and for me things improved mightily with the combination I spoke of. YMMV of course.
I had much better luck with the Sierra bullets with varget, which incidentally Sierra has pretty good luck with, and with the 69 grain version, most accurate. For 55 grain, their accuracy load was with RE-7, but they did list H 335 as a prefered hunting load. Where they do find H335 shining is with their #1370 SMP bullet, 60 grain showing 25.2 grains H335 @ 2.250.
For the 52 and 53 grain Match Kings, where the 52 grain is HPBT, 53 grain being HP (with flat base) their accuracy load is with Viht N133.
I had the 69 grain match kings and varget doing well (again, what Sierra found most accurate) when I started in with the 53 grains. I tried H335 but wasnt having much luck getting below 1 inch. (100 yards) going with Varget shank them under 1 inch.
Gun, nothing special, AR15 I assembled as a "SPR". Anderson upper and lower stripped receivers. Front of upper receiver squared by hand lapping with Brownell lapper and a Dewalt drill. Barrel is a Ballistic Advantage (super inexpensive at Monmouth reloading) 18 inch SPR barrel, which they guarantee 1/2 moa. 1/7 twist. Spikes LPK, Geiselle 2 stage trigger, Rock River A2 Operator stock, tube, spring and buffer. Nikon 4-12 x40 scope on a Nikon mount.
Nothing exotic, just thrown together in my garage.
I do have a bunch of H335 on hand, and will try it more, but I did go through 8 lbs of it, so am familiar with it. Most of that fired through a different AR, about the same as the SPR I describe here, but with a 16 inch Ballistic Advantage barrel.
As an aside, I might add most benchrest shooter seem to prefer stick type powders. So as to not go to far off thread, I will start a new one over 50-69 grain bullets and prefered powders.
Russellc