I shot about 100 rounds out of my marlin 22 LR today.
I have red lines on my shoulder/upper arm that more or less match the edge of the butt-pad. ten or so vertical lines. I guess they are bruises.
I notice this same pattern sometimes when I was shooting trap a lot. Usually only one or two and not every time I shot.
When I shot trap I assumed I took a shot or two without the gun pulled in tight and it bruised me. We went through several "Mad Minute" courses of fire, so definitely could have had bad stance there. I can't believe the 22 had enough recoil to cause bruises even if I was not holding it tight. The Marlin is light, but not that light. I noticed nothing while shooting.
Is this indicative of a certain technique problem?
Since the bruising is also on my upper arm I guess I did not have the rifle in the pocket either.