Need advise on using Wilson case gage

[Tom15034]

Sorry to keep bugging your guys but I am new to this precision reloading.

I stick a new Lapau 6mm BR case in my new Wilson case gage and the base sticks out of the gage upper step around .001". Not bad but I thought it was supposed to be below the surface. OK, maybe it needs run through a sizer. I stick a fired case in and it sticks out .007-.008 from the outer surface. I clean out the gage and try other cases and get same results.

Do I have a chamber that is too long? If I resize a new case and bump the shoulder down a smidge it will be below the gage surface. However, the fired case will then be at least .009 longer.

Tom

 

[Forum Boss]

Hmmm,

I normally only use case gauges for pistol ammo. Here's what Sinclair says about the Wilson: "Headspace of fired cases can quickly and accurately be measured using this tool and a pair of dial calipers.

This one piece gage will check overall length to indicate need for trimming, datum to head length to assure correct headspace and to prevent over sizing. Available for most popular rimless cases."

Is there a lip inside on which the neck stops? Could be you're simply a thou or so past Wilson's max trim length.

Could you post a picture? I'm a little uncertain as to what you're describing. It would be very strange for OAL to change .009 during case sizing.

Also, what is your rifle and who did the chamber? Is this a "pre-fit" barrel?

Check your fired case vs. our cartridge diagram:

 

[Tom15034]

Sorry Paul, I don't have a camera to post pictures. I was hoping someone knew about the Wilson gages.
Tom

 

[keithcatfish]

Something isn't quite right. The upper and lower steps of the gage represent the maximum and minimum headspace dimensions. I frequently find unfired brass,Winchester brand 308 Win especially) that is less than minimum headspace. When a fired, but not resized, case is placed in the gage, the base should be between the upper and lower steps in the gage. This indicates that the rifle's headspace is within acceptable limits. I have never encountered a case that is too long BEFORE it is fired. I suspect that the gage may be at fault or since Remington brass is made to slightly different specs, the gage may be intened for use on Remington brass.

 

[NorCalMikie]

I have and use the Wilson Case Gauge on my Lapua 6BR as well as my Remington XP100 Rifle in .221 Fireball. The Lapua "new" unfired brass is flush or below the upper step. I have set the headspace on both of my Savage 6BRs to keep the brass in the gauge specs. A full length resize that "just" touches the shoulder makes the cases fit the chamber and the gauge. Same for my Remington .221 brass.
I have the gauges in .223,.221,6BR and .308.

 

[Tom15034]

Thanks for the replys. The Wilson case gage is pretty cool! When I pop a case in enough times you can see the rub mark around the shoulder where the datum line is being measured. Its about 2/3 up the shoulder.

The base of my new Lapua cases stick out of the gage less than .001". That is the upper step or the longest step. Fired cases stick out .005-.009", depending on the load. Hot loads stick out further. The ones that stick out .009 are hard to close the bolt on. The OAL length between new and fired, measured with calipers, does not change significantly.

From what I can dig up, the headspace of a Rem 6BR is the same as a Norma 6BR. Assuming the gage is good, my chamber must be long. I can still use the gage to set up my FL resizing die.

Tom

 

[rvander1]

I use a RCBS Precision micrometer set. It consists of a base and two tops to screw on-- one measures headspace, and the other ogive,these are for measuring brass and seated bullets).I like these gages becasue they are machined to accurate specs,mimimum ANSI specs is zero on the gague). The gagues come with a chamber headspace gague which I have only found workable with the ejector removed. Hard to completely explain how this gage works, but if you're interested I'l scan the instructions and attach them to a post. Not sure they'll help unless they make one for 6mm Br and I'm not sure about this. I have Davidson gages which are similar to the stony point gages-- slightly different approach to same probllem. I'm pretty new to this stuff- don't know what most benchrest shooters use- would be an interesting question on the "poll".
Hope this helps.
Bob

 

[Hipshot]

RCBS Precision Mic gage set does not come in 6BR. However, I found this tool so useful I had an insert made so I could use their .243 Winchester gage set for 6BR. The insert is made of aluminum rod stock, just short of the diameter of the base of the RCBS unit, with a length exactly the difference between a .243 Win case and a 6BR case measured from the base to the datum line on the case. I also had a hole drilled in the insert just like the hole at the bottom of the RCBS unit, where an extended primer would go into. I really, really like the RCBS precision mic set; I did find the case length gage that's in the package to be less than useless.

As for the Wilson case gage; I also use one for 6BR. At this point it's used to check the gun's chamber.

A person can't have too many measuring tools; just know their use and limitations.