I have used LBT blue soft at all velocities and it was adequate, White Label lubes meet all my needs now and then some, mainly use 2500 with odd forays of BAC.
All my bullets start at least 1 thou over groove diameter unless there is a generous freebore and then it is best to use bullets that meet this dimension.
Under groove size bullets rarely work unless they are soft enough and the charge robust enough to bump them up to groove dimension ‘pon ignition.
With an undersized bullet I am not surprised that it was all over the place, personally I never use hard lubes never got them to work as good as soft but then I am not shooting in tropical climes.
Hard lubes are like hard bullets the product of the commercial bullet caster, they have nothing to do with performance but everything to do with keeping their shape and staying in the grooves during carriage, presentation is every thing, fur coat and nae knickers.
At the end of the day your shooting will only be as good as your postion, hold, natural alignment, sight picture, shot release and follow through. Environmental conditions also play a large part especially light on the target and sights.
I still manage to shoot with a V notch sight as most of my guns are military bolt actions and very few of these have apertures, as age overtakes me and my eyesight diminishes then so does my shooting but on a good day I will expect my V notch sighted rifles to deliver at least 2 moa with worked up loads, I am sure that they will do better but that is the limitation of my shooting nowadays.
I’ve used Ben’s Liquid Lube on everything for the past 2 years. Very good lube and the absolute easiest way to lube. I coat used for pistol bullets and 3 coats on rifle bullets to 2500 FPS with no leading and first shots always in the group, no first shot flyers.
The new formula for Ben’s Liquid Lube can be found posted as a sticky on the Castboolits website.