Model 1 Sales 300 whisper upper function problems

[300whisper_newbie]

Jripper Wrote :

I just purchased a Model 1 Sales 300 fireball upper in a 16 " CAR configuration. It looks like a well made piece, but when I went to shoot it it would not cycle the action with any of the 3 corbon factory loads (220 subsonic, 125 and 150 supersonic). It appeared that there was not enough gas pressure to make it work. I have a JP adjustible gas block on order, and a reduced poundage buffer spring. Should the JP gas block take care of the problem, or is there any other modification/change in the gas system I need to make?

The bolt locks up somewhat tight, but otherwise looks like it is in working order.

Thanks