[fpotter]

Okay - I've read all the posts and done most or maybe all of the stuff recommended. But I still have a specific problem figuring out what it all means.

Let me take a precise case in point (precision being what this whole thing is all about, no?). I have an Armalite AR15, shooting .223 Remington rounds. The factory length of rounds is stated to be between 2.250 and 2.260 inches. And the rifle shoots factory ammo okay - not great, but okay.

So I haul out the rifle and a bunch of variously weighted and shaped bullets, together with the Stoney Point OAL gauge and the Sinclair comparator. Here's where it gets complicated.

A Sierra Match 53 gr bullet, put into the OAL gauge, measures an average of 2.183 inches. Add that to the Sinclair comparator and I get a measurement of 2.812. How, taking all these things into consideration, do I construct a dummy round, which I can use as a template from now on? (Other weights run from 55 gr--2.147 (2.821) to 69 gr--2.227 (2.813)).

In theory, at least, the factory round may be touching the lands in my rifle when it is put into battery (or at least so it might indicate). I suppose that I could do the comparator on that round as well, but I'm not sure what that would tell me.

If I sound confused as hell, then I've described my situation perfectly.

Frank