SmallCaliberCentral

A concentricity gauge doesn't necessarily measure the case neck. As you turn the LOADED case, the point/tip of the gauge rides the bullet rather than the case neck. This lets you measure the amount of wobble that was induced into the bullet as it was seated in the case neck. That measurement doesn't take the thickness of the case neck into account.

The second, case neck thickness gauge, simply measures the thickness of the unloaded case neck, at the point of the measurement. It could be thicker on one side or the other before turning it to a uniform thickness. Some "tight neck" chambers have less clearance than the standard. The case neck, in some instances must be turned so that the case neck will fit into those chambers. Two completely different measurements.

There are more details that I'm purposely leaving out right now so I don't confuse the issue. Just the basics.

Randy, the neck turning tool actually removes brass from the case neck...the high spots only, or a full cut to a predetermined depth to fit your chamber dimensions. The tools are adjustable to vary material removal.

The concentricity tool measures the degree of concentricity on a case neck, a loaded round, or any part of the overall cartridge. With this tool you can determine TIR (Total Indicated Runout) or "wobble" of a loaded bullet. This shows you problems that may exist with your dies or technique. A very valuable tool. MIne came from Holland's Shooting Supplies (Darrell Holland - Master Riflesmith) in Powers, OR. Excellent tool, but Sinclairs has a selection and is probably the very best source for accuracy-related stuff.

For the kind of accuracy most here seek, both tools are necessary. See Randy.....we're "purchasing mentoring" you here.......

"Purchasing Mentoring" sounds so much better than helping to drain your wallet.. Love it. Bill K

As long as we're spending your money, only the best will do!!

Gee, thanks guys. With friends like this who needs a spouse? LOL! Seriously though, I've never received any bad advice from this forum-maybe some that I don't agree with but not just bad advice. I hope Jim, the OP got the answers he was looking for-I'm pretty sure I got what I was looking for, the experiences of those who have done what I haven't-yet. Randy.

Randy, something to keep in mind in regard to accuracy......

During my young years spent at drag strips racing my small block Chevy's, the speed shop we all haunted had a large sign over the counter that read:
"Speed Costs....How Fast Do You Want To Go?"

Apply that statement to accuracy......just how much accuracy can you afford?

The guys that are shooting agg's in the zero's and one's got there by spending more than a trifle amount of money, myself included. It's up to the individual as to how much money is worth it to get those dinky little groups or the ability to hit that PD or squirrel in the head as he pokes his head up out of his mound at 400 yards with the first shot.

This can be as expensive as one wants it to be, but the constant factor here is that accuracy costs, period.

Sidebar: My wife likes asking me how much gear, and how much money it takes to kill a silly squirrel. Girls.....they just don't get it!

Sidebar: My wife likes asking me how much gear, and how much money it takes to kill a silly squirrel. Girls.....they just don't get it!
I get the same thing-especially about how much did the fish I caught really cost? Boats and guns=boy toys and they're all expensive. Randy.

We all know the cost would be cheaper to just go buy prime beef/pork, etc. and how can you count the cost on ground squirrels/rock chucks and such ? It goes beyond that and that is what we seek. I know my wife asks here and there, do you need another one of those ??? So all of us just keep working and enjoying our little time in life and the wants and needs.. But is it not fun ? Bill K