I suggest you replace the the spring, and drill out the AR's the AR's are things that restrict air flow, they are in the bolt, the thing that chambers and holds the dart, some silisone lube and mane even a little tape under the o-ring to get optimal seal would be advised. If you do replace the spring, you may also have to reinforce the bolt sled, I suggest you go to the modifications directory and read through every guide for the long-shot their is.