Measuring chamber length

[Old Chap]

Pete,
I noticed this when I first started using 2156s a couple of years ago. I believe that there is a very slight difference at the "full dia" junction which is amplified over such a very shallow angle. I now always advance 2156s over 2155s by 0.012". Mind you that probably is the reason I live in the 3 ring!
Regards
Phil

[ovenpaa]

I do and a large magnifying glass to help me read it! Thinking about it do I just set the bore size and slide it down the bullet?

I have a cunning plan, I will PM you

[EagerNoSkill]

Save money
Buy Bearing surface comparator from "the Toolshed"

Also measures overall length on ogive

Fast consistent accurate

[Jenks]

I have always thought that Chamber length did not involve a measurement of a cartridge case and bullet. Surely then you would be measuring cartridge length. Out of curiosity I made up a little gauge to measure the maximum length of cartridge case that the chamber of my 6.5x55se could accommodate.




the rim of the brass billet is exactly the same diameter as the external diameter of the case neck.


Jenks

[Watcher]

You want one of these. I have the honour of being the test pilot for one of Ovenpaa's latest shiny things.

[Jenks]

Watcher..

I do have something similar....

http://www.6mmbr.com/catalog/item/1433308/977259.htm

It is not calibre specific as Ovenpaa's appears to be. I'm sure that would make his a little more accurate. Unfortunately I bought mine about fifteen years ago.... I don't think Dave was making them then

Jenks

[ovenpaa]

Jenks, I used the Hornady inserts initially, one at the bottom only then took to making my own inserts, then started building a base to align the case head, then added a dowel to align them and bump inserts.

This is the latest generation and includes bored internal diameter to better than .001" a lapped face and a tube which is used to align both the upper and lower sections.



The one Watcher is using is effectively one end only without the alignment sleeve.

[Watcher]

Watcher..

I do have something similar....

http://www.6mmbr.com/catalog/item/1433308/977259.htm

It is not calibre specific as Ovenpaa's appears to be. I'm sure that would make his a little more accurate. Unfortunately I bought mine about firteen years ago.... I don't think Dave was making them then

Jenks

...and mines shiny; which at my level of expertise means a lot :?

[Jenks]

Jenks, I used the Hornady inserts initially, one at the bottom only then took to making my own inserts, then started building a base to align the case head, then added a dowel to align them and bump inserts.

This is the latest generation and includes bored internal diameter to better than .001" a lapped face and a tube which is used to align both the upper and lower sections.



The one Watcher is using is effectively one end only without the alignment sleeve.

Dave..

That really does look like a well made piece of kit. I particularly like the fact that the cartridge head is firmly supported. I do find that just using the comparator without such support can be a little tricky if one is trying to get an accurate reading. Which of course is the object of the exercise.



Jenks

[ovenpaa]

This is the assembly together ready in the vernier with the setting sleeve, this means you cannot fail to be out of line so you will always get more consistent results. I fitted and removed the gauge a few times using this test round and typical variations were .0000" and .0005" so it repeats to within half a thou with my vernier and feel.

I could never get my Hornady inserts to read this accurately and I must admit this is one gauge that is going to go on my reloading bench.