Problem: Gun has worked fine with my current setup for 5 weekends. This last time out it developed a problem where after a 5 or more round burst the paintballs only shoot about 10-15 feet. During my troubleshooting I noticed that the rod going into the IVG in the back of my gun had come loose, so I fixed that. That did not seem to have an effect on the problem and it still did the same thing. With limited knowledge I did take the reg apart and didn't notice anything wrong to an untrained eye. I reassembled and it is still giving me the same problem.
If anyone could give any ideas on what to check out it would be great.
If you haven't changed any settings, and it's shooting fine at a lower ROF and only giving major dropoff during rapid fire, you have the right idea. It's likely the HPR. Could be your bottle reg as well, but it's not likely to be anything else.