I wouldn't worry about the bolt bounce as long as the gun ran.
I'd run to a Lowes, HD, ACE, and A #60 O-ring. If they worked, I'd order this:
http://www.bravocompanyusa.com/BCM-E...exspring-1.htm
The reason is because the hardware store version will likely be buna rubber and will deteriorate. The others are viton. With the BCM kit, you may not need it because the spring is so strong. It would be a cheap test to see if it fixes it.