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.
Thanks"
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
