Turok<BR>Now that you have broken it down finer, I finally get it. This is a good point.<BR>Up until now, I was going on the assumption that my chambers were in fact round.<BR>One more variable to the long list. Some target shooters do in fact place their rounds in chambers, in the same position to make everything as consistant as possible from shot to shot. If one uses a referance line on the cartridge anyway, it would of course make it easy to position it in the chamber to eliminate this one variable.<BR>My old friend, who did advise me of the measurement method ,did not make referance to this point.It was discussed on the topic of benchrest shooting. I will confer with him about it, to get his views. <BR>Up to this point, with the rifles used, any readings I have taken, have corresponded to the increase or decrease of powder used.With the exception of some readings taking a large<BR>increase, with only a small amount of powder being added. This of course is where I would determine where I wanted to stay with my load for this round. I would agree if the chamber was in fact out of round, this could help increase(decrease) the measurement,and your suggestion of placing the cartridge in the chamber at the same position each time, is a good one. If this variable does in fact exist in my rifles, I would suggest it is of small enough significance to not have affected any of the loads, I haved deemed safe in my rifles. I also suggest relying on an average of readings from several firings, rather than a limited few. <BR> One day soon, I'm going to have to give my lady the bad news, and tell her the new Oehler 43 is on it's way. It is after all in the name of safety, right?<BR>Surviving this, a bore scope should be easy. [Linked Image]