[kciH]

You can also get a similar product from Sinclair International, the benchrest people. The Case Master is a good tool,in that it has more uses than just concentricity measrurements, but that is the main function. I bought one when they came out years ago and it gave me the confidence to send back a set of dies to a respected manufacturer that I otherwise would not have suspected as being the problem. The dies where the problem in this particular case. The tool will show you if your case necks are correcly aligned with the casse body, as well as overall bullet runout, this is helpful in deteriminig if the problem is with your chamber (fired brass), your sizing die (resized brass) or your bullet seater or seating technique (bullet runout). If you use the tool in the above sequence while reloading it should point to the problem area if it is indeed with the ammunition. If you are a competitive shooter that loads large batches of ammunition (such as high-power rifle) you can sit down and separate your loaded rounds and reserve those with the least runout for actual match shooting. Another feature is that it has a easy way to measure thinning of the brass in the case head area so you know when to throw away brass before a case head separation occurs. You can also use it to measure neck thickness, which can be detrimental to accuracy if it is not uniform. If you shoot a number of different guns, or are a precision shooter, it's worth the $65-70 that you'll have to shell out for it.