I can't find o-ring sizes for the AEA Challenger .30. I get a puff of air coming from the transfer port between the upper and lower. There was no seal in there from the factory and I suspect it uses an x-ring instead of the o-ring I put in but I'd like to know for sure.
EDIT: A factory defect from over drilled holes is eating the o-rings and letting air escape on each shot.
EDIT: A factory defect from over drilled holes is eating the o-rings and letting air escape on each shot.
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