Case to bolt face gap

[Frameman]

Hello all,
I’ve looked all over the web for good info regarding the case to bolt face gap measurement and still can’t be sure.
Is there a definitive source for this info?

[CINDERS]

There required information will be given if you could stipulate what it is for the 6.5mm or 7.7mm Arisaka seeing as the post is in Japanese Rifles the guys will be along shortly.

Welcome to Milsurps by the way.

[Frameman]

There required information will be given if you could stipulate what it is for the 6.5mm or 7.7mm Arisaka seeing as the post is in Japanese Rifles the guys will be along shortly.



Welcome to Milsurps by the way.

Thanks for the welcome and sorry for the omission.
7.7 is the info I seek.

[Sunray]

Being a 7.7 one assumes it's a Type 99?
That "gap" is called headspace. Isn't actually measured because it's a rifle manufacturing tolerance, only. Headspace just gets checked with proper gauges.
Pacific Tool and Gauge custom makes 7.7 Jap headspace gauges upon order for $37US each.
You can rent a 'Go' and 'No-Go' for 3 days for $7 from Reamer Rentals too. Probably better for a one time thing.
7.7 mm x 58 Arisaka Headspace Gauges - Pacific Tool and Gauge
7.7mm Japanese Arisaka Headspace Gauges
Put the rifle in a padded vise then slip the gauge under the extractor(if you know how to remove it, that's a bit better.) and gently close the bolt. The bolt should close completely on the 'Go', but not close completely on the 'No-Go'. 'Completely' being the operative word.
Plan 'B' is to take the rifle and gauges to your local smithy. Do not let him tell you he must buy the gauges. You will pay for 'em and not get to keep 'em.

[Frameman]

Being a 7.7 one assumes it's a Type 99?
That "gap" is called headspace. Isn't actually measured because it's a rifle manufacturing tolerance, only. Headspace just gets checked with proper gauges.
Pacific Tool and Gauge custom makes 7.7 Jap headspace gauges upon order for $37US each.
You can rent a 'Go' and 'No-Go' for 3 days for $7 from Reamer Rentals too. Probably better for a one time thing.
7.7 mm x 58 Arisaka Headspace Gauges - Pacific Tool and Gauge
7.7mm Japanese Arisaka Headspace Gauges
Put the rifle in a padded vise then slip the gauge under the extractor(if you know how to remove it, that's a bit better.) and gently close the bolt. The bolt should close completely on the 'Go', but not close completely on the 'No-Go'. 'Completely' being the operative word.
Plan 'B' is to take the rifle and gauges to your local smithy. Do not let him tell you he must buy the gauges. You will pay for 'em and not get to keep 'em.

I believe that “headspace”is measured from the datum area on the shoulder of the case to the case head by means of the gauges you mentioned. I’m looking for the measurement between the bolt face and the case head. They are not the same.