Mine needed to be on the 700 m mark to be near the bull at 50 yrds. I fabricated a spacer because with washers there was a space that I couldn't tolerate on a $500.00 + rifle. Then the wooden stock decided to fall off as I had one of the early versions with only two attachment points. To their credit ATI did take care of this under warranty albeit slowly.
Honestly all that's needed to fix this is a spacer, it could be plastic that would be fine.
When I read that you got yours cheap and with a rebate I realize buying one the week they came out wasn't a very good idea
I was fired up at the idea of the MP-40 for a while, now I think I'll wait a good long while before making a decision.
Honestly since I started reloading I shoot a lot more 5.56 than 22lr and with the currently craziness over 22lr it's not really that much more expensive.
Bit of rambling here but I don't understand why ATI doesn't offer a cheap injection molded plastic spacer, even if they offer it as an accessory.