Why do you say that?, I have shot my Springfield M1Aa lot and the commercial bolt works just fine. I here this a lot from people on different forms and I have always wondered why they state it. I personally think it's more being able to say your rifle is all USGI as opposed to just usable functioning parts. Besides USGI bolts are not cheap anymore, NIW $200 and up, ($350 for a TRW)and used(some from parade rifles that have the weld on the face ground off and re-drilled)for $150.