When I was at my last command while I was in the Navy, I joined the Auxilary Security Force and we used paintball for training. But some of us bought our own gear and started playing every Sunday afternoon in Nassua County, near Yulee and Fernandina Beach Florida . We even had some of the sheriffs deputies play with us. I had a Customized spyder.
The most painful hits I ever received were from a mini mag that chrono'ed at 320 fps. I was hit in the neck and the unprotected part of one of my fingers. The one on my neck looked like a huge hickey but the next day it had a huge scab on it.
The most painful experience I ever had while playing paintball was when I was in a low crawl (like in this picture)
And I was waiting on a teammate to get in position so that he could provide me some cover fire. I'd been laying there about 5 minutes when I noticed something tickling my neck and chest . I finally couldn't take it any longer so I scratched it with my hand . When I did that my whole chest, neck and lower face seemed to catch on fire. I had been laying in a bed of fire ants but hadn't noticed them biting me do to concentrating on not getting shot. I layed there and yelled that I was out and not to shoot me because I was coming out of my mask and some of my clothes. When they acknowledged that they understood me, I jumped up and started a little dance number trying to get rid of the ants. I hurt for days and to add insult to injury a person on the other team who hadn't heard me call myself out shot me as I was heading back to my car.