low velocity

[azheat99]

Set up Level 10 with 1.5 carrier(no leaks) and 2 shims. Tried medium and short spring but max velocity only 250's with short spring and air released from rear with medium spring when turned up. Trimmed a little more off medium(per AGD suggestion), but still released air from rear. Gun is a Micromag RT. Any suggestions?

[Load SM5]

You possibly need to replace your reg piston if you're venting out the back. I had the same problem as did quite a few people.