Spent some time measuring the brass.
The same 50 cases I weighed.
For over all length.
The longest was 1.541.
The shortest was 1.5385.
The average was 1.5395.
Case necks.
There is a very slight burr on the inside and outside of the neck.
They dont look like they were trimmed but there is a burr.
I deburred 5 cases and came up with....
The outside neck diameter is .2674 for a 5 piece average, checked with outside 0-1 mics.
The inside neck diameter is... .241 goes and 242 starts but wont go all the way in.
i used minus gage pins.That mean the pins are .0002 under the nominal number.
The .241 diameter pin went in all 100 cases. NO dents or dings on these case mouths. NONE..
For checking neck wall thickness.
I did not have tubing mics.
I have what are called pin and anvil mics.
i came up with .013 to .0135 neck wall variation ( worst case ) out at the case mouth.
This increased to .014 and .0145 as I got closer to the neck shoulder junction.
Flash Holes.
I set up a Brown & Sharpe vee block. Glued a block as a stop on the vee block end, and clamped the whole mess down on a surface plate.
Used a surface gage and a Interrapid .0001 indicator and checked the run out on the flash holes.
So im checking the concentricity of the flash hole diameter against the outside body of the case....
Simple set up, you just put the case in the vee block and slide the case head up against the stop.
Spin the case and read the indicator.
I was getting .004 to .0045 total indicator run out and I checked 20 cases.
This means that the flash holes are about .002 out of center to the case body.
I could have reset the indicator point and checked the primer pocket but I didnt think of it..
I then got a .080 minus gage pin and checked the flash hole diameters.
A .080 - pin has to be pushed in and then pulled out. The diameters are a fit to the minus pin.
I checked a pile of them and the flash hole diameters are all the same to .0001. Amazing close
Next up.
I always have Randy make me a stub gage made with the chambering reamer.
We take the 1 inch off the end of the barrel and use it for finding the lands for bullet seating and checking headspace.
He uses a go headspace gage and writes the number on the gage.
I took a couple of fired Lapua cases and checked them against the new Alpha cases.
The Gage says 2.266.
Fired Lapua cases say 2.266 2.267.
Unfired Alpha cases measure 2.265 2.266.
Took a bunch of Alpha cases and put them in the gun.
Bolt handle went down on all of them...no problem..
happy..
dave
dave