Do I need a concentricity gauge?

Kelly Timoffee

Kelly Timoffee

BANNED
BANNED
BANNED
EE Expired
Rating - 100%
52   0   0
Location
Prince Albert, Sk
I am not shooting F-class, heck I barely shoot when anybody else is around at all.

I am however always trying to improve and better my results.

Will I benefit from checking my ammo this way?

If it is out of round you obviously have to correct something right?

Will this just lead into more tools and nick-nacks and a guy chasing his tail trying to get accuracy he will never get?
 
If you are gonna check out of round then you probably should check centre of gravity/mass as well. If the bullet isn't spinning exactly on the longitudinal axis then its gonna fly.
 
Tagged.

I thought about getting one but was unsure if there will be a HUGE increase in accuracy. I guess if I'm shooting 600-1000yrd range, the error would be much more visible. Curious as to what other have to say.
 
It will also depend on the rifle your using. If it is your average hunting rifle you will not see much difference. I suspect you'll need a rifle that is built to tighter tolerance before you'll gain a lot, but what the hell more toys on the bench when you keel over means more inheritance for your kids.:D
 
If you don't want to get fancy just roll your ammo on the table and watch the bullet tip. You will get an idea of how bad your ammo is or isn't.

Honestly I have found concentricity to be one of the LEAST important things out there. Consistent and correct neck tension is about 100X more important judging what I have seen. Perfect example, I have one rifle that shoots great with lots of neck tension, 0.003 to be exact. With that much neck tension the bullets seat crooked, but the accuracy is there. If I load the same ammo but only have .001 neck tension the bullets seat very straight, less than 0.002 run out but shoot like ####. Correct and consistent neck tension trumps concentricity in that rifle.

Another example, I have a custom rifle I built it is heavy and capable of better than 1/2 minute accuracy, when I anneal case necks the gun shoots unbelievable, when I don't and let the necks work harden the gun starts to shoot 2X as large groups. One time I culled out some rounds with very bad run out, over .005 and shot them separately, they shot exact same group size as the other "perfect" ammo. With this rifle, consistent neck tension trumps concentricity as well.


No double there are going to be guns out there that are sensitive to ammo concentricity but I haven't found one yet.
 
The concentricity gauge allows you to check the brass, once fired vs resized or necksized. Most of the time you will notice the sized brass is not as straight as the 1X brass and from this you may have to change your sizing process a bit. This applies to the target shooters.
 
b72471 said:
The concentricity gauge allows you to check the brass, once fired vs resized or necksized. Most of the time you will notice the sized brass is not as straight as the 1X brass and from this you may have to change your sizing process a bit. This applies to the target shooters.
Click to expand...

It also checks the run out after seating a bullet , which IMO is a very important factor to control. I bought a Sinclair concentricity gage and I don't know what I would do with out it. If your thinking of taking you reloading t that next level ... I would say most definitely yes ! you will need a concentricity gage.
 
pilot2001 has a very nice simple runout gauge and I would highly recommend the one he has.

NOTE: More inaccurate ammunition is reloaded with excessive runout due to the decapping rod/expander button being locked down off center than any other reason.

Good dies reduce neck runout, and brass with unequal case wall thickness increases runout.

Having a good runout gauge will drive you nuts with improperly setup dies and bad brass. It will also tell you if your doing something wrong, the problem is figuring out what is causing the runout.

"Some" of the information below for many of you with standard factory made rifles "MAY" be overkill and time wasted, BUT every little bit helps. Also note that Accurateshooter.com has a ton of information about reloading and improving your rifles accuracy.

Complete Precision Case Prep
Preparing Cases for Long-Range Accuracy
http://www.accurateshooter.com/featured/complete-precision-case-prep/

How to Load More Concentric Ammo (pilot2001 runout gauge) ;)
http://www.accurateshooter.com/technical-articles/reloading/how-to-load-more-concentric-ammo/

O-Rings on Dies May Reduce Run-Out
http://www.accurateshooter.com/technical-articles/reloading/o-rings-on-dies-may-reduce-run-out/

The Riflemans Journal below is also a good place for info.

Reloading: Seating Die Runout
Seating Die Induced Runout - A Comparison
http://riflemansjournal.########.com/2009/09/reloading-seating-die-runout.html

Basics: New Brass Preparation
http://http://riflemansjournal.########.com/2010/12/basics-new-brass-preparation.html
 
Kelly Timoffee said:
I am not shooting F-class, heck I barely shoot when anybody else is around at all.

I am however always trying to improve and better my results.

Will I benefit from checking my ammo this way?

If it is out of round you obviously have to correct something right?

Will this just lead into more tools and nick-nacks and a guy chasing his tail trying to get accuracy he will never get?
Click to expand...

I would say yes to the run out gauge, especially for someone trying to improve loading and shooting. The gauge used on fired brass will show if cartridge case is thin on one side. Gauge will show what sizing dies are doing, and how straight bullets are seated into cases. I don't use my run out gauge all the time, but its a great tool for trouble shooting.
 
I bought one and glad I did ,I measure all my rounds. anything .005'' or less is for my long shots on predator varmint , any thing over .005'' gets the runout marked on the brass and is used for 200 yards or less . Any rifle I have that uses a clip , I always buy a 2'nd clip that way I keep my measured ammo separated out in the field. most of my neck sized ammo is usually my straightest,, when I full length resize, thats where I see my excessive run out on about half my loads. they do affect my size of groups on paper. minimal run out is usually 1/2'' ,anything excessive might give me a 1'' group
 
From other threads I know the OP is seeking reasonably accurate (better than 1MOA) ammo.

You don't need to buy a concentricity gauge, but it would be worthwhile to borrow or use one a bit. Measure your ammo as you are currently loading it and see if it's straight. If Total Indicated Runout ("TIR") is three thou or less I am fully happy with that level of TIR in match ammo that I'll shoot to 600y and 1000y. If it is 10thou or more, there's a problem somewhere that can be fixed (either the sizing die making the neck crooked, or the seater die not pushing the bullet in straight).

Once you've used a concentricity gauge to investigate (and fix if necessary) errors in your process or tools, you don't really need it anymore. You don't need it to make good ammo, you only use it when you get worried and want to check that the ammo you're making is straight (enough).
 
I just bought the forster case inspector from Sincair. I will have to let everybody know how well it works. I will be using it mainly to measure case neck thickness and case neck runout to see how well I can turn my necks. Anybody here ever use the Forster version
 
I use mine every time I load, and at each stage. It will tell you immediately if something is wrong. I check my fired brass, and use that as a baseline as I move forward. After sizing (neck or FL) I check it again to make sure my die is setup right and not inducing runout, I then check it when I seat a bullet, and adjust or change something if I need to.

Sometimes I will find something isn't right causing runout, such as a piece of crap in the threads or under the lockring, with the first case, fix the issue, then after that all is well.
 
You must log in or register to reply here.
Back
Top Bottom