FL sizing issues...Fixed!

[fguffey]

After further great comments I spent about 10 minutes on the lathe again and made a gauge similar to the Hornady one only with a 40° shoulder angle for my Ackley cases. Thank you again everyone for helping me and inspiring me to get even better. As it turns out, I am now setting the shoulder back .001" with the dies and the newly turned shell plate. The bolt now closes properly on the round. Again, much thanks!

Joe C. "I spent about 10 minutes on the lathe" The case friendly gage can not be zeroed without a standard. Matching the shoulder angle of the chamber/case is not necessary, for years smiths and reloaders thought the datum was a line. The datum is a round hole, the datum for the 260Ai is the same datum as the 308W, the round hole is .400" in diameter. Putting a radius on the edge of the datum changes the 'measured from'. I have little interest in making a case friendly gage with a radius, I prefer the gage I can zero.

The Wilson case gage is a datum based tool, it uses a radius on the datum. No one wants a ring around the shoulder caused by the sharp edge or a datum.

With comparators, the diameter is not important as long as the same diameter hole is used.

F. Guffey

 

[BoydAllen]

For purposes of setting a FL die, I do not care what the numbers are, just the difference between them. I use dial calipers and although I could rotate the dial so that it is zeroed with the Hornady attachment in place, long ago I decided to standardize on leaving it zeroed jaw to jaw, and noting the tool that was used to make ogive to head measurements ( I have a couple), and for setting a die, as long as the caliper is not reset between the measurement of the fired and sized cases, there is absolutely no problem. Even when checking a fired case against a headspace gauge, this is the case. The absolute number does not matter, just the difference. This is not to sat that what others do or prefer is incorrect, as long as what they do works.

 

[fguffey]

For purposes of setting a FL die, I do not care what the numbers are, just the difference between them. I use dial calipers and although I could rotate the dial so that it is zeroed with the Hornady attachment in place, long ago I decided to standardize on leaving it zeroed jaw to jaw, and noting the tool that was used to make ogive to head measurements ( I have a couple), and for setting a die, as long as the caliper is not reset between the measurement of the fired and sized cases, there is absolutely no problem. Even when checking a fired case against a headspace gauge, this is the case. The absolute number does not matter, just the difference. This is not to sat that what others do or prefer is incorrect, as long as what they do works.

Boyd Allen, that is wonderful.

Joe C. The next time you are at the lathe I suggest you drill holes that measure .420". .375". .400" .330" and .407" in diameter. The numbers provided are the diameter of datums/round holes for deterring the length of the case from the shoulder/datum to the case head. There is a variation that can be made for specific cases, beyond that there is a variation that can be made using the standard datum diameter.

F. Guffey

 

[BowGuy]

WOW!!! Did everybody see that flash?

Another , not often enough, flashbulb moment.