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Old September 10, 2012, 06:02 PM   #1
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milling your own headspace gauge?

I have a friend who is a milling machine god. I want him to create a headspace gauge for my Arisaka type 99. Where can I get the dimensions needed to created the go and no-go gauge.


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Old September 11, 2012, 08:53 AM   #2
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I am by no means a machinist...but I'm pretty sure you need a lathe to make go no-go gauges, not a mill.
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Old September 11, 2012, 11:31 AM   #3
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the thing you to know is . . . . .

The length the gauge needs to be from the base to the datum line.
It's some where on the shoulder taper as measured from the base.
The gauge really can be just a peace of miled steel cut to the right length and a minim diameter. Or you can fire a round and measure the fired case and you can see the actual chamber condition.
As a gunsmith I do this all the time. (Do not try this at home) (unless you live in the woods.)

Last edited by norsecat; September 13, 2012 at 11:27 PM.
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Old September 11, 2012, 04:00 PM   #4
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For what it costs to buy or rent headspac gauges, I don't see why anyone would even try to make them. Use the time to do paying jobs.
Never try to educate someone who resists knowledge at all costs.
But what do I know?
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Old September 11, 2012, 06:42 PM   #5
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The way a headspace gage would usually be made goes like this:

1. The steel is turned to perhaps a few thousandths over length and a couple thousandths over diameter.

2. The steel will be hardened.

3. The gage is then ground to final size.

4. The size of the gage and go/no-go/test are engraved or etched into the side.

If a gunsmith had a lathe, a small heat treat oven, a tool & cutter grinder, and a book of chamber prints (available from Pacific Tool & Gauge) he could make a for-real headspace gage.

As it is, I'd prefer to just call up Pacific Tool & Gauge and say "Hi, I'd like to buy a headspace gage for a Type 99 Arisaka..." and the nice lady on the phone would say "OK, that will be $X and take time T to be done."

As to making one on a "mill" -- I could sorta do it by putting a piece of drill rod into a chuck in the mill, put a lathe bit into the vise and "turn" the material to size on the mill... but what a bizarre job.
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Old September 12, 2012, 12:58 PM   #6
F. Guffey
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Milsurpaddict ask,

"I have a friend who is a milling machine god. I want him to create a head space gage for my Arisaka type 99. Where can I get the dimensions needed to created the go and no-go gage.


I have never thought head space gages were made on Mars by Martians. Gages are made by people, I am a people.

Mill? I have 2 grinders, I make pilots, I make tapered pilots. I make tapered gages, the head space gage is a nice tool to have, not necessary, just nice. The head space gage is a fixed gage, we all know the go-gage will allow the bolt to close when chambered, the go-gage will not allow the bolt to close in the perfect world, when the bolt closes on a no go-gage the bolt closes, back to the start, we do not know 'by how much'.

'By how much' and no one knows, except me.

Before the Internet by 35 years +/- a few years a smith/author wrote a book, included in his book was a section on gages, he could have made his own, he choose to purchase his head space gages, then he wrote he had friends that used other methods that worked, he did not claim one tool was more accurate than the other, he simple wrote he choose not to make his gages.

Making gages, to make a gage a reloader? should have confidence in their ability to measure case length from the head of the case to the shoulder of the case, the reloaders confidence should extend to their ability to measure the length of the chamber from the bolt face to the shoulder of the chamber. The reloader should be able to understand the term minimum length and full length sized. Then there is go-gage length as it applies to the chamber and no go-gage length and field reject length.

Again, after the gages are made, they are nice to have but not necessary.

A collector/shooter and owner of reloading equipment was making every attempt to save money on cases for his Model 99 Japanese rifle, he took the time to post questions on the Internet, there was no value in the responses he received, basically in their opinion it could not, should not etc., etc. be done. I contacted him off the Internet and offered to form cases for his rifle, I formed cases in groups of 20, minimum length/full length sized, go-gage length, no go-gage length and field reject length. He loaded and fired the cases that were minimum length/full length sized, he loaded and fired the cases that were go-gage length with a hint of resistance to bolt closing, the cases that were no go-gage length would not allow the bolt to close, the cases that were field reject length would not allow the bolt to close.

I met him at the Dallas Market Hall Gun show to help him with other questions he had about other projects and I introduced him to resource people.

He lived west of Ft. Worth, TX.

Anyhow, I Have grinders that in-line, angle and butt grind, the lathe is a better choice for making gages than the mill, again, if a reloader can measure a case and chamber for length and understand the datum is not a line on paper with an arrow they should be well on their way to understanding gages.

F. Guffey
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Old September 12, 2012, 03:56 PM   #7
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Not long ago you did not just order many of the foreign gauges and reamers you needed. I did notice THE GUN PARTS (Numerich Arms) had Arisaka gauges listed a few years ago, if you are inclined to buy them. I made many a reamer and gauge. I don't think it was more than 20 years ago (Before SAAMI was on the net) when I called to get reamer dimensions for a .22 HI-Power. The guy that answered the telephone told me he never heard of it. I think back and the SAAMI book was pretty small years back. The foreign stuff was even worse to find.
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