Good idea but - R&D Precision PW9 Colt/Glock 9mm 5 inch Upper Receiver Kit

After putting this all together ran through a few trial and errors. First the guide rod broke and spring bent. Second the firing pin broke. Looking at the design of the bolts Carrier Group and firing pin design it leads me to believe the firing pin will break again after replacing. R&D precision is very helpful and very quick on shipping replacement parts. Also note the Gen 1 model is designed f o r 9mm Luger 115 grain. As it said in the letter I received with the item.