I dont get the difference between the wear on a semi phantom and a pump. Obviously the parts will wear out faster with the semi becuase you would most likely be generating more shots in the same "life span".
The problems that most people find with auto-nelsons is'nt the shoot down...the recharge rate at full pressure on a nelson valve is better if not similiar to any standard blowback. Porting and volume is similiar also. I cannot tell you why folks like Palmer abandoned the nelson valve system for the sheridan or tube stacked design.
We have all seen plenty of examples where a autonelson design works just fine at a high rate of fire. Think AT, punisher...ect.
I also had a auto-traccer that didnt suffer any problems(outside from timing issues)...we actually had a firestorm crank and a halo on it at one point.
"I wish simply to be a decent person, yet I will always fear the retards" -Brian Hindt(geech) MCB Moderator Kidney Machine