I have two personal examples that may shed a little light on this subject. In boot camp I was working the butts at Camp Elliot, carryiong targets from the line to a small shed. During this time the range was in use. Having my left arm out and turned slighhtly upward, carrying a large target frame, I felt a heavy "thump" on my left wrist. When we got the target put away, I looked and saw I was bleeding slightly. A cease fire was called and I went to the firing line. A Gunner's Mate pulled a .30 caliber bullet out of my arm, apparently from a ricochet, bandaged it up, and I went about my business. Upon our return to San Dieago, I went to Sick Bay nad a doctor looked at my arm and bandaged it. I lost no time in boot camp. Many years later the arm was x-rayed after a fall. Lo and behold, there was another bullet, still in my arm! it seems there were two, and we only removed one. The other is still in my arm.
Also many years later, I was firing a Manhatten Arms pocket pistol, .31 caliber, at an oak board. One round bounced off the board and hit me in the left shoulder. I was wearing a tee shirt, cotton shirt, flannel shirt, and a light jacket, so the ball did not break the skin. I did, however, get a pretty good bruise, and it hurt quite a bit. There is now a keloid scar where the ball hit me. Had the first wound been the result of enemy, rather than friendly, fire, I would have been considered to have been wounded. The second, was "just one of those things." I hope this helps in the decision making process.
For a real wound, consider my great uncle, Frank. He was hit in the left shoulder by a Minie' ball at Spottsylvania in May, 1864. The ball broke his left scapula and came out near his spine in the small of his back. In July, while at home recuperating, he was captured and sent to Camp Douglas. He said in his pension application that exposure there gave him rheumatism. Later he had no use of his left arm, but I do not know if that was from the wound or from rheumatism. Stan