I'm curious to hear what your COAL is. I did a dummy cartridge at max SAAMI COAL in my Ruger African and got the bullet stuck in the barrel and eventually had to back it off to the 2.95" sadly.
I am using 120gr TTSX in mine and have worked up a few loads of IMR4831 to try whenever I can get to the range.
Standard procedure with a new bullet it to seat it long (as in max length that will fit the mag) and see if it chambers. If not, seat it deeper and deeper until it will chamber without leaving marks. Note that in the log as max OAL for that rifle/bullet. That is what you just did.
I find 6.5 develops pressure quickly, so I always start then load development with the Start load. Once even that was too hot.


















































