I HAVE talked to Wil Shumann (April 19, 2007) about AA7, and he stated that at one time AA7 was in fact a gritty powder that eroded the barrel. However, it was completely reformulated years ago and that now is is no more erosive than any other powder out there. He mentioned the fact that he has used several HUNDRED pounds of it through his open gun with no erosion! He also mentioned that Hodgdon had a similar problem with HS7 eroding barrels and Hodgdon reformulated HS7 and renamed it Longshot