I envision the problem with the can on the barrel, is you are increasing pressure just ENOUGH, and it is back pressure toward the action, to swell the case just enough, to not extract.
If you are using IMR BLUE, it is different than Blue Dot. Close but each has different load data, especially near max.
If you are using Blue Dot, and a 55 grain Hornady SP, MAX Load is 13.5 grains. 14 grains is starting to tread in the danger zone.
I'd back the charge with the can back to 13 grains... if the problem persists, I'd back it down to 12.5.. MV will be around 2600 fps or so.
It should be just fine...
another solution for that , is drop your bullet weight back to either 50 grains of the various 52 or 53 grain bullets...
max load at 13.5, and if the problem still persists, drop back to 13 grains.
