Question for hornady fans.

k2man, I don't know for certain, but guessing mostly because the hole isn't exactly .400" in diameter. I'm sure the softness of the aluminum doesn't help either, although the edges do look nice and crisp.

FWIW, I just rechecked with my Forster .308 Win and .223 Rem go-gauges to get some actual numbers. I had forgotten that I also modified the .223 insert. Anyhow, measured 1.6285" instead of 1.630" marked on the .308 go-gauge and 1.461" instead of 1.4636" on the .223 go-gauge.

I did get the same readings 3 times in a row on each gauge, so it's still good to go as a comparator, but no more so than before I modified the inserts..
 
k2man, I don't know for certain, but guessing mostly because the hole isn't exactly .400" in diameter.
Click to expand...

K2man was confused because he asked about the bullet. Now we are talking about .400”; that puts us into measuring the length of the case from the datum to the case head.

Again and again there is something about measuring from the datum that drives most to the curb. It should not be that way. The only reason the hole should be .400” in diameter with a sharp edge is when comparing the measurements to SAAMI specifications. Problem; SAAMI does not list head space for the case because the case does not have head space; but for all other purposes and the relaoder understands he is using a comparator the hole only has to be a hole and the sharp edge does not matter.

Back to the beginning; measure before firing and again after firing. When it comes to sizing a case measure before sizing and again after sizing. One more time purchases a head space then validate the length of the gage from the shoulder of the gage to the head of the gage. That is easy if the reloader understands the concept of ‘zero’. When using a comparator the reloaders needs to understand he is using the comparator to determine the difference in two lengths.

I blame Googlers; Googlers google ‘head space gage’ and believe that is all they need to know..beside bumping. There is the case gage, there is the comparator and there is the datum.

F. Guffey
 
Thanks F. Guffey. I see that tolerances can throw off absolute measurements. I know we don't need to compare to SAAMI specs really, but if we are taking measurements, why not design a gauge that measures a dimension that is a specification, rather than just some random spot. I know it isn't going to matter in our end results, but it's kind of like saying "my flyrod is 63" between the first and eye and the tip" instead of saying I have a 7 ft. flyrod.

So we just use the gauges as comparators, just as Hornady says. I think my gauges should have been finished with a little more precision. If you can see my photo that I posted earlier, my gauge has a big scratch in it - it looks like they took a crude tool to debur the edge. If I'm going to have tools that I want to measure to sub .001" accuracy, I don't want poor machining on them.

I'll call Hornady. I just looked at all 5 of them in the set, and my bullet comparators, and it is only two of the headspace comparators that have nicks and scratches in the contact edge.

higgite you are right there - soft aluminum is not the right material to use here. But I hope that they used a reamer to get the final hole size not a drill bit or an end mill.
 
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