"We go 30 inch pounds on our steel receiver guns we buy and 18 inch pounds on our Aluminum receiver guns we buy using our screws. Our base screws are longer than most others."http://www.dnzproducts.com/faq/
Based on the note above, feel inside in the lug/bolt areas to make sure the screws are not protruding through and making contact with the bolt or lugs.
Read all of the info on that link, it is very good and thorough, well worth the time.