I haven't notice any other bruising out of the ordinary. I am not taking any medication that is meant to thin blood or has it listed as a known side effect.
I may be pressing too hard.
The butt-stock is not extremely soft, but it is rubber. The slip on kick eez pad I have for my shotgun is much softer. I wonder how an easily compressed soft pad effect aiming.
The shirt does not have a pad sewn in. It is Beretta shirt that is more or less dedicate to shooting and hunting. I have considered adding a pad before, but I never followed through. May be a good place to start.