I was out today checking "MY" YP1000 with a 100' steel tape at my range and the results were from 100-800yds at 100 foot intervals( the river was high and kept me from going beyond that ). All measurments were taken useing the point that say 99yds switched to 100, not 100 to 101 or the center of 100. I placed steel concrete form board stakes every 100yds for checking in different conditions and color/type targets later on. At 100yds it read 103yds exactly. Not exactly + or - 1yd. as advertised, but before the I told ya sos speak up, every other 100 foot interval was EXACTLY ON, not off by even ONE yard. 100,133,166,200,233,266,300 and so on. So there you have it. After the 100yd reading I was kind of nervous, at the end I was shocked, and thankfull. I thought the 3yd error at 100yds would multipy or be constant. I could care less out to 300yds anyway. Back to the range again with some more loads, my wife took the kids to visit their little friends in Kenai so I don`t have to sneak to the range today( all the fishin gear is gone, I think their going after some king salmon without me ).