Gauge, inspectors, headspace, 7.62 mm rifle

[nzl1a1collector]

Its taken me years to finally get my hands on one of these monsters, but now I have no idea how it was used on the L1A1 rifle.

GAUGE, INSPECTORS, HEADSPACE, 7.62 MM RIFLE M.L.
SM 104A
5220-99-960-6621

Has anyone use one of these and if so, how was it used... am I missing a part? or does it work with standard headspace gauges? Anyone have a EMER reference for its use?

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[browningautorifle]

Very nice, can't wait to hear from Peter and the others what the poop on this is...

[nzl1a1collector]

Just to show the scale of the gauge.

[tankhunter]

If I recall correctly, there should also be a 'Plug' gauge that sits in the cartridge chamber. When you fit this gauge in the carrier rails in the receiver. It butts up against the 'Plug' & the locking shoulder.

I think this was used for locking shoulder confirmation sizing for Headspacing? As 'Normal' Headspacing was enacted with a 'Go' & 'No Go' pair of gauges.

I recall being taught how to use one of these. But it was a VERY long time ago! & I never used one subsequently in Service. Just the Go/ No Go Gauges, as was the norm.

Peter will I'm Sure, be able to confirm exactly the usage level of Scaling.

[nzl1a1collector]

Ahhhhhhh that might explain this gauge I have on one of my lists

1005-99-960-6608
GAUGE, inspectors, headspace, 7.62 mm. rifle, Mk. 2

This might be the gauge used with the other gauge.

now to find one of these........ somewhere it never ends.

[mrclark303]

Great find Kevin,

Yet another interesting L1 related collectable, I bet, stuck at the back of a shelf, under 2 inches of dust in a RNZALR Armourers workshop somewhere is the part you need to complete this!

[browningautorifle]

The pic makes it all fall into place now, the gauge mentioned will be the key. Then you just assemble the correct locking shoulders and carry on. I wonder if this was more for assembly of rifles than weapon tech's toolboxes?

[Peter Laidler]

That was the gauge to use at Command and Base Workshops to ascertain the size of locking shoulder required to bring an out of CHS rifle into the tightest CHS limit. Locking shoulders were a press fit and every time you pressed a L/S in place, it made the next L/S looser. So to save guess-work or keep removing and replacing sizes in number sequence (and like No4 bolt heads and Bren barrel nuts, L1A1 L/S's didn't follow number sequence in real life) until you got it right, this gauge gave you the thickness of L/S you needed to use. The thumb wheel turned the peg (photos 5 and 6) downwards until it bore against the slight front taper of the L/S which pushed that part of the gauge rearwards. Is there a read-out on the front shaft? That way, it might not be EXACTLY right, but it would be within spec first time. Without having to faff around, opening up the L/S hole every time. Oversize L/S hole = ZF

I think that there was a calibrated gauge that went into the chamber and register on the datum diameter of the neck. It was from this gauge that the l/s size was taken.

Like Tankie, I saw the gauge in use, took it all on board for a few weeks and then got down to doing it how we always used to! But it was a time saver and prevented worn bodies becoming even more worn. When we were apprentices we had to use the gauge to do all this stuff because we had to strip our bench rifles to the last minute item. Then every part from everyones rifle was put in a sheet, shaken up and............... Then you started again!

[nzl1a1collector]

I've been over the gauge with a fine tooth comb and some bright sunlight and I can't find any markings on the dial or the front section which compresses against a spring. Any marking or graduations must be on the second part to the gauge.




The Australian's had a much simpler system of gauging the correct size of locking shoulder required, they had 3 tapered gauges, two had the various sizes of Locking Shoulders and the third was for gauging the required shaft diameter. This was a much simpler system than the British or Canadian methods.

[tankhunter]

Pete, I recall using in it on my Inistial Armr's course, in 'Rifles'. With the Personable Ben Gunn, & the Late Denny Billborough. But never used them subsequently. Even though I had a brief 6 months detachment form the School of Infantry. Down to 27 Command Wksps. I was only employed there doing out inspections, on the refurbed Weapons that the Civvies had worked on.
And later on the refurbing of captured Argie Weapons. And subsequently later on, the very sad destruction on them!...

I thought this gauge was more locking shoulder related, rather than headspace. But time dulls the memory as You might empathise! LOL