I aquired one of these and found out that there was a design flaw. Now to some, it may not mean much, but It's something that stuck in my head. After looking at the replacemant screw, I noticed that it did not have the drain hole drilled through it like the A1 or A2 screw. Like I said, to some, that may not be a big thing, but to me it was. I like the idea for the A2 stock, but that one thing turned me away from useing it.