I have never had a problem getting one to run. The gas ports are not the issue most of the time it is friction. The bolt rubs everywhere. I use a buffing wheel on the bolt and a dremel for the tight spots. The big mags some time need some attention as well. The secret it to be aggressive removing material. I have a buddy that worked 2 weeks trying to get one to run. He a opened 4 hole gas so far it turned into one hole. He buffed it so well it felt like a tuned 1911. Finally he figured out the shells would not eject because they would not clear an eotec he had on a quad rail. now the damn thing will run primers only!!!!!!! That story is a lot funnier than told it.