Measuring Case wall thickness/irregularity

[RN]

So....Being a little ocd and wanting to turn out top quality ammo I am on the hunt for a tool that will asset in case measurements/runout issues. I also want to be able to check for pending case failure without using the paper clip method. I have seen that the RCBS case-mate system will allow for this but I could not find any others. All the other big names just measure case HEAD thickness and bullet run out from what I can tell.

Any others out there that I am missing? Seems like an easy enough tool to make and if there is one thing I have learned about re-loaders, its there is a tool for everything so wheres this one?:banghead:

 

[Rule3]

TriCorder

 

[mdi]

Regular tubing micrometers work quite well, but here are some dedicated reloading tools for measuring case thickness;

http://www.sinclairintl.com/search/index.htm?k=case+thickness+measuring&ksubmit=y

http://www.sinclairintl.com/reloadi...meters/digital-thickness-gauge-prod36561.aspx

http://www.sinclairintl.com/reloadi...ries/neck-wall-thickness-gauge-prod69425.aspx

 

[Reloadron]

There are plenty of good tools out there for measuring things like neck thickness on bottle neck cases. Assorted ball micrometer fixtures like some of those seen here.

As to beating the paper clip to predict case separation failure? Yeah, that can be done but I figure the reason nobody markets a system aimed at hand loaders is because of the cost. Ultrasonic thickness testers come to mind. Make a fixture to hold and slowly rotate a case while a thickness transducer rides the case and transitions from head to case mouth. Heck, you could plot the case. There are also what are called capacitive sensors that would work. Someone familiar with NDT (Non Destructive Testing) methods would be familiar with the assorted thickness testers out there but they aren't cheap. Most hand loaders prefer a simple paper clip and "feel".

Ron

 

[Walkalong]

As posted, you need a ball micrometer to check neck wall thickness, although there are some other reloading specific tools for it. Agh, I see Ron has already linked to some.

 

[Rule3]

Seems all those tools measure case neck.

As the OP inquired about the paper clip method for internal case wall or case head, are there any tools that measure the case body internal thickness??

 

[ClarkEMyers]

I don't know of any specific tools aimed at the reloading market. I'd ask Brownell's and Sinclair and more of the bench rest specialists. A bent anvil could be used with something like the Redding case neck dial indicator to measure deeper in the case. Of course practically that's equivalent to running a bent paperclip along the inside with a readout.

Nothing I've seen will easily setup to locate the thin spot which may be at an unknown distance from the case head and vary with cartridge case. Where the thin ring falls is likely related to how many steps in drawing the case and work hardening. I've seen separations in .41 Magnum cases at quite a different distance than in a .30-'06 case. I don't think it's worth doing but you may think it is. Mostly I figure that if the necks where it's easy are uniform than the body where it it's hard will be uniform. A bore scope will show incipient case separations but so will good headspace control - everything from an L.E. Wilson case gage at the low price end to a Redding Instant Indicator at the high end. I've only had one chamber that was way over long (I have had some ammunition that was way off spec from the factory though), leading to a visible bright ring that was perfectly obvious and just as obvious with a paper clip and just as obvious when I sectioned a case and just what I expect when I saw how much extra headspace there was.

 

[RN]

@rule...that's what I looking for..Seems the RCBS does a little of everything and could be nice..How many freaking tools are needed to get the job done..jezzz..I want to be able to KNOW when to cull bad cases and get rid of any runout..RCBS casemate ok for that?

That leads me to my next question.. What's more important in terms of accuracy? It seems the Hornady Concentricity tool will read bullet runout AND make a somewhat useful attempt to correct it. Is this really doing anything if the case neck is not true? A lot of guys say the Horandy really does help but then again some say it's fixing one issue while another issue still exist in the actual case neck..I would be ok if the Hornady fix worked..

Do you need to check case neck runout AND bullet runout or is the Hornady a good comprimise to keep you from buying 10 tools to do improve accuracy?

 

[Reloadron]

Seems all those tools measure case neck.

As the OP inquired about the paper clip method for internal case wall or case head, are there any tools that measure the case body internal thickness??

Yes, I mentioned ultrasonic thickness testers in post #4. The problem is that using devices like this to measure a case wall thickness and do it accurately is not at all cost practical. That is likely why nobody markets such a device to the reloading enthusiast.

How much would you be willing to pay for a tool to measure case wall thickness? What features would you want in such a tool?

RN:

That leads me to my next question.. What's more important in terms of accuracy? It seems the Hornady Concentricity tool will read bullet runout AND make a somewhat useful attempt to correct it. Is this really doing anything if the case neck is not true? A lot of guys say the Horandy really does help but then again some say it's fixing one issue while another issue still exist in the actual case neck..I would be ok if the Hornady fix worked..

The guys who really get into this stuff are the serious bench rest shooters. You want to find cool and expensive tools then you start here on sites like this. Generally they will look at a case neck and check neck thickness at several points around the case neck. Following bullet seating they check the bullet runout. They also look at other features. Each of these features does effect accuracy, the question becomes how much is the effect. How much does uniform case neck thickness bias accuracy? You get into an unending list that to the average shooter becomes unimportant. Finally unless a shooter has a high enough end rifle with a very high end barrel most of this stuff won't even matter.

Just My Take....
Ron

 

[Walkalong]

Exactly right. Hunting rifles shot off hand or even rested against something won't benefit from painstaking case prep.

And if one is that concerned about brass, buy Lapua to begin with.

The RCBS tool is the closest to the all around tool you want, but for a hunting rifle, I just want safe brass of decent quality.

 

[Zeke/PA]

There's quite a few Tube/Pin Mics available to measure case NECK thickness.
Aside from that, I think that you might be getting " carried away"!

 

[brickeyee]

I took a simple Sinclair block that was designed for a micrometer head and adapted a ten thousandths dial indicator to work in place of the micrometer.
Just spin the case gently on the stud and watch the variation.

Sort into groups.
I use the larger variation brass on shorter varmint shots, and save the really tight ones for the long shots.