When ever you read, "loaded to equal pressures" you know you are reading a pile of bs.
...I'm curious...what kind of velocities are you getting out of your 30 Gibb? ...and at what pressure?
I rechambered a Ruger #1B (26" bbl) in '06 to .30 Gibbs. Measured (Oehler 35) 3,050 fps with a 180 gr bullet! Primers fell right out of the pocker upon extraction. Probably about 80 kpsi. Backed off 2 grains, and it would do 2,950 fps. Powder was RL-22 and was known for unexpected/unexplained pressure excursions. I had shot the same charge weight before without any warning signs. Have not used RL-22 since (about 20 years now).
