From RL338 post looks like a mag primer and a different powder are in order. First time I've seen you getting a little butt kicking in load development.
I have a severe mucus problem coughing up mucus most of the day. Ear,nose,and throat specialist said it can be a gasttric problem. Do you eat alot of processed food. i've been making this it really helps.
Dan hodgdon doesn't list it for any 270 data. But does list Staball 6.5 and Staball match for the 270. I did load some Staball 6.5 with a 140gn bullet and it shot well.
Sorry to hear of your uncle's passing. Beautiful flintlonk. Use 4f in the pan and don't cover the flash hole. I fill a 270 case with 2f for my powder charge.