Love it best thing since sliced bread - Magnetospeed Sporter Barrel Mounted Ballistic Chronograph

First off you have to understand that I have never used the old style chronograph but from what I have read they where kinda a pain I have a creed Moore that I want to shoot out to 1000 yards and needed the muzzle velocity so I got this one and it works great my barrel is 1" diameter so I don't use any shims and it lines up perfect even with a tank style muzzle break reads every shot stays put very easy to use now on my 308 not so because the hanguard sticks out so far it doesn't sit rite but that's not the magneto fault so one it works great the gun I bought it for and the other gun I will have to mess with no biggie.