I just got a pre-ban M4 flattop upper to put on a pre-ban CAR-15. The only problem was that the flash suppressor wasn't firmly screwed on. I took it to my local gunsmith and he told me that the upper had been put together with a peel washer and that I need to get a 'crush' washer instead.
Question: what is the difference in a crush washer and a peel washer?
Which one do I need to screw down the A2 flash suppressor on a PREBAN upper?
Where can I get which ever one that I need? Bushmaster has them both for about two bucks and some change, but they have a minimum order of $25 or something like that. I just ordered an offset pin recently in order to put the new upper on my old lower, not knowing I would need another $2 part. I had to order something else to reach the min, so I ordered my ARMS #40 for them. Sucks when you have to spend $100 to get a $2 piece!!!!!
(Oh yeah, Bushmaster doesn't give a description of what a 'crush washer' or a 'peel washer' is? Thanks alot! The former is $2.50, the latter is $2.95)