yes, I realize that, we are talking lube for conicals not PBR to stay on point. Again, SPG was talked about by Idaho Lewis and he preferred his formulation.SPG is bullet lube.
I tried SPG in my early use of two 58 cal Navy arms gun. Either I wasn't using the right bullet/lube/velocity combination or my expectations were too much for the relatively slow twist and very shallow rifling, but I could never get those 58s to be 125 yard guns. Lucky to get them out to 100 yards, but accuracy was inconsistent with the velocities I wanted. My best was sub 1150fps with a 460 gr minie with an OP wad that gave me great accuracy at 50 yards but velocity was such that the drop at 125 yards was well over 6 " and I had to hold 3.5" high at 50 for a 100 zero. Just not what I wanted so I headed down this rabbit hole in search of the right combination. I am glad I did as I have learned much.
My goals:
A gun that can hold 3" group with ghost ring hunting sights at 100 yards, drops no more than 3" at 125 yards with that 100 yard zero and retains no less than 1200 ftlbs of energy at 125 yards and has through and through capability and a modest expansion, all out of a carbine of no more than 24" in length and preferably 21-22 inches in length that is around 7lbs total weight.
Yes, I know..a kabuki dance to be sure, but I know what I want and I believe it is achievable with the right combination of twist, bullet, lube and powder.