I recently acquired a new Ruger bisley blackhawk in 45 acp/45 colt. I slugged the chamber throats with a lead sinker and with my micrometer I measured .451. I did the same with the barrel and got .450. The lockup was not great.
I began shooting 45 acp rounds with it to some success, but I finally got everything together to load some hard cast. I opted for Leadhead's 310 gr .452 diameter with new Starline brass, CCI 350 primers, and planned to use H110 since I had plenty on hand that I use for my 44 mag. In looking for published data, I had hard time coming by anything. I finally decided to try the data from John Linebaugh's website which is 21.5 - 23.5 grains. These were stiff loads but they proved accurate at 23.5 grains. I shot several 4 shot groups at 20 yards around 1 - 1 1/4 in size. However, as I shot these loads the high pressure signs began to add up. Though I am extremely pleased with this loads performance at 20 yards and beyond, I will not be shooting this load anymore as things presently stand.
I shot 20 rounds working up to 23.5 grains and around 20 more at 23.5. In those rounds I punctured a primer at 23.0 gr. This concerned me as I had never done that before, but I carried on. At 23.5 one round had a different sound and another punctured primer with a stuck case. I stopped at this point. Throughout, I noticed a few instances of small crimp jump, which I believe I can take care of if I were to shoot this load again.
So, how would you proceed?

Does it not shoot well enough with < 23 grains?

Starting at 21.5 I put 4 shots in for 2 1/2. 22.0 was 1 3/4 and 22.5 was 3 1/2. The 22.5 gr group had a flyer that may have been my fault. Three shots for this group measured 1 1/2. Again, these were all from 20 yards.
Perhaps this makes too much of group size, but I am more concerned these loads are not safe in my gun. I guess I would expect these loads to be safe in a strong revolver in good working order. Does this mean I'm screwing something up, the gun is not squared away, or that these are just hot loads and I should be content sticking to lower charges?

I would suggest rerunning your test using Fed 155 primers. I was recently doing testing for a 44 Mag using W296 and CCI 350 primers, and had similar results (pierced primers, flyers). All the problems went away using the Federals. My loads were at or below book max, but I still had pierced primers. My CCI 350's are several years old, purchased during the great primer/powder/ammo shortage. Prior to the shortage, I always used Federals with no problem. Bad batch or lot, I don't know. Just a suggestion.

I would try to chrono the loads and compare velocity vs the velocity of your data. More velocity probably means more pressure.