Pump mag troubleshooting

[Smokee_2_7]

The whole idea is to have it high enough to contact the bolt face and still low enough for the bolt not to hit it when the rod is all way forward....

Is it normal for the tip of the arm to be tapered? I ask because I noticed that the tip was either shaped, or slightly worn (presumably from dragging the rim of the bolt). Just trying to learn as much about these things as I can. Thinking about building one myself!

[flyingpootang]

Rounding of the end is normal wear caused by the rod sliding against the bolt face. Good luck on the pumpmag build, their great since it's impossible to double feed and you'll never get roll outs. A lot of members have had problems with tuning pumpmags because they didn't understand them. 99% off the problem is the pump rod angle the other problem is a compressed wave spring causing it to shoot semi. To keep the wave spring or any other spring from getting fatigued is to remove them when not in use. PM me if I can help you in any way...
My Pmags