Re: Chops, chops, and more chops
Hopefully you've solved the problem by now. I have the old MR2 myself, and it chopped all the time (about every 4 balls) until I did some surgery on it. I took the bolt out and clipped some of the acs spring off. I know some people say to not do that, but it made the acs perform Much better. I can put my finger in the breech, fire, and the bolt bounces off my finger all day. I also put timmy detents in, and I'm running a spyder fasta 18v loader. Since I've clipped the acs spring, i've not chopped a single ball. That was a few cases ago. I also run the APEX on the BT AK47 barrel, and it's not that hard to clean. 4 screws, hot water, and you're good to go.
With my gun set up the way it is, I have the range and ROF to be a true annoyance to anyone on the field. Just be careful clipping the acs spring, only take a few millimeters off at a time until it performs the way you want.