Shoulder Bumping & Case Head Clearence

Nice job Walkalong. This i made quick to check 223, told me i had a bad Dillon shell plate. Click photo for larger pic. [/URL][/IMG]

Nice job there Walk!

I just goes to show that it doesn't really matter what you use to measure, only that it is consistant between measurements. You could have used the hole with out the sloped shoulder and it would have worked just the same, but that was a nice touch, it will help keep the case aligned better too.

If you had step drilled it on the other end bore diameter and put a leade, you'd had a bullet and a case comparator combined.

Nice tinkering!

Jimmy K

Got a lot of old barrels laying around .... but they are hooked to some stocks!

I use the Sinclair # 2 hex nut looking thing(comparator) for shoulders, usually the .338 hole or which ever fits best for the shoulder measurement.

I use the #1 comparator for the bullets , it covers all the calibers I have.

I Use my calipers for the measurement from the top of the comparator to the base of the brass, if I want to get real ticky, I drag out the Indicator dials and base.

Before I purchased the Sinclair Comparators, I used a large hex nut and drilled holes that fit what I needed.

Like you said It ain't got to be fancy to work!

Jimmy K

Head space guages and competion shellholder

Stoney Point Products, now Hornady makes a Headspace Guage with various inserts and Redding sells a Competion Shellholder Set which will allow you to resize a cartridge so that the shoulder is moved back a bit so that the cases are not over worked. I use both, the tools work.

And all those products were probably first made up by some old codger like Walkalong, while setting watching it snow in Alabama!

Jimmy K

AC said: A short piece of .22 cal barrel is what would be best for making a piece to use as a bullet comparator.

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Now that is good thinking.
Hmm, I have old sizing dies. Seating dies, too.

Jimmy K-- You are right ,some our best rounds and tools came from wild catters and home hobbiest.. I started reloading in 1953 with a Lymon Tru Line Jr press and small diameter neck dies. Military surplus 4895 and 4831 was the powder for the 100 and 130 Gr bullets for my 270. Over the years I got some the tools the bench rest shooters use for reloading my varmint rifles. I like new ideas .

And all those products were probably first made up by some old codger like Walkalong, while setting watching it snow in Alabama!

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Hey, I'll have you know, Walkalong is a young codger!

Don

Yea!

But it is still snowing in bama!

And GA too!

Weather lady on Fox said it was the first time that snow has been on the ground in all fifty states at the same time!

So much for Al Gore's global warming!

Jimmy K

Nice work again, I see you've been busy with the lathe again.

Jimmy K

Walkalong, if you ever decide to mass produce these, I'll buy it! Hell, maybe two or three!

Walkalong, you can do better than the Hornady, L.E. Wilson and the tool I call a contraption, I do and all I use is what most would call junk, on occasions I travel to Alabama to visit family and my wife wants to see a Hoover HS football game this year, the family lives in Norther Alabama near Huntsville. So let me know and I will bring some DATUMS, those are those things I find at gun shows that are sold as miscellaneous junk.



F. Guffey

Walkealong, I have a set-up table, the top of the table is a datum when measuring height.

Again, the datum for a case and or a chamber is a round hole or circle, the diameter of the hole for the 30/06 is 3/8 " or .375.

I make a seating tool for a 25 cal like the 25/06 that is similar in appearance to the tool you have illustrated except it is used for seating bullets with neck support, the tool sets on the shoulder, the first cut supports the neck and the second cut centers the bullet. The seating die is one of the most overbuilt tool the reloader owns, I can use a can crusher to seat bullets with this tool if the base of the crusher is parallel to the crusher when lowered.

The ideal gage for measuring case length from the shoulder (datum) to the head of the case would not have a shoulder, it would have a hole the shoulder of the case would sit on,

Rather than take the time to look up datums I make them up, my case my chamber my datum, the results is the same.

As a suggestion the next time you chuck up a piece in the lathe, cut a hole through it that will accommodate the neck, then make a straight bore cut on the bottom instead of an angle, this will allow the case to center on the neck and sit on the datum (diameter of the counter bore/second cut), then remove the tool from the lathe, stand it on it's end, insert a case and with a depth micrometer (other end of a dial caliper0 AND MEASURE FROM THE TOOL (DATUM) to the head of the case.

Again I determine head space first then size cases by transferring the measurement to the press, die and shell holder.

There are some that can not get past the datum as being anything but a line, all I need to know is the diameter of the circle at the datum, again I have no problem making one up for my use but the ideal the go-gage is a precession tool is lost on me, I can measure the go, no and beyond gages with my datum system, if I can do that what do I need the expensive gages for?

For those that have a L. E. Wilson case gage, insert a fired case in the gage, use a flat face punch on the head of the case and hit the punch so the case is driven into the gage, no shoulder, the case will require a little help getting out but the shoulder will indicate a datum, measure the diameter, it will be close, the ring on the case of a 30/06 will be .375 or close.

You are correct, what I do can seem to be vague to very vague, I have a motive, the motive is to provoke someone into thinking, more times than not I am only half successful, I provoke without getting some to think, there lost.

Thank you for asking.

If you want datums purchase R. Lee's book on modern reloading, or be like me purchase anything cheap that has round holes in it, bolt gage, wire gage, drill hole gage metric and standard and the list goes on and on.

F. Guffey

Is that not the same as I do with the Sinclair Hex tool?

I'm measuring from the datum(where the hex hole contacts the shoulder) to the base of the brass.

I use what ever caliber hole for the cartridge so that it fits about mid way the shoulder.

I mostly use the calipers for measurement, but if I want to be picky I get out the magnetic base and dial indicator.

Jimmy K

Walkalong said:

So what you are saying is to cut the tool to sit against a small portion (the datum) of the case shoulder instead of the whole shoulder. I thought about doing that. Probably would be a more precise measurement of where one is supposed to get the measurement from instead of wherever the shoulder is hitting against the angled part of my home made tool. I may play with that soon. Overall though, my little tool works well enough for me. AC

While I thought about cutting the tool the way you suggest, I did not think about getting the measurement this way. What about variances in the thickness of the cases head front to back?

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This has been a great thread, but finally you managed to confuse me.

First, in my mind a datum is a "start location" may be a physical point, a line, or even a point in time.

His datum is the point the shell hits the offset in the tool's bore, right? (the point from which head space is measured in the chamber) The other end of that length measurement is the rifle bolt surface, which is the same as the bottom of the case's head...right?........so.........what does the head's thickness have to do with it? What am I not understanding here?