7.62 mm Incremental Headspace Gauges Set.

[Bruce_in_Oz]

Leave them sealed up and, if you have a need to examine chambers / headspace to such fine degrees on a regular basis, get a commercial set..

Clymer sold me a nice set of "incremental" gauges years ago and I subsequently coughed up for a similar set in .223Rem / 5.56 x 45.

These not only take the "guesswork" out of evaluating complete rifles, but tell you exactly what is happening when doing chambering jobs.

[Bruce_in_Oz]

Update to my last:

The gauge set you need is made by "Forster"' and marketed by the helpful folk at Brownells. 7.62 version contains 9 gauges in increments of 0.001"

[nzl1a1collector]

ok......., ok....., I won't unwrap the gauges

I don't need to, here's a nice set I managed to do a deal for over the weekend.

A set of 10 Lithgow Small Arms Factory Cartridge Headspace Control Gauges.

[Peter Laidler]

Wot...., no 1.643, the reject gauge for the old L1A1. Maybe the factory only allowed up to 1.642

[mrclark303]

ok......., ok....., I won't unwrap the gauges

I don't need to, here's a nice set I managed to do a deal for over the weekend.

A set of 10 Lithgow Small Arms Factory Cartridge Headspace Control Gauges.

Another great find Kevin, well done mate

[nzl1a1collector]

Wot...., no 1.643, the reject gauge for the old L1A1. Maybe the factory only allowed up to 1.642

The Australians had a different set of Specs for their headspace gauges:-

1.6325 inch (ACCEPT)

1.6380 inch (REJECT)

1.6400 inch (CONDEMNING)

The gauges are laid out as above.

From Left to Right:
Original Mk. 1 Gauges.

Modified Mk. 1 Gauge (1.6400). The rims were removed to stop them being damaged when someone leaves the extractor in.

Later 'stepped' gauges I guess they would be called the Mk. 2? Although I haven't found anything official calling them the mark 2 gauge.

[nzl1a1collector]

British headspace gauges:-

1.6325 inch (Go)

1.638 inch (Inspectors)

1.643 inch (Reject)

[Peter Laidler]

I liberated the gauge for calibrating our gauges!
I agree with you about the gauge numbering. I don't think that there was a change in the SM number when the 'rimmed' gauges changed to 'rimless' so to speak. It was just a natural progression. The rimmed gauges were OK when used carefully but some idiots would insist on a quick stuff it in the chamber, whack the breech block closed and swiftly eject gauge onto the floor.......... Criminal!

[nzl1a1collector]

Since we are dealing with headspace gauges, has anyone any knowledge about what was contained in this box? Other than what is listed on the lid. I've never seen SM 121A or SM 757 gauges and I don't have any references to these numbers.

What's interesting is the user states they are for the Rifle 7.62 MM L.1. not L.1.A.1.

Could these be ex Navy? (being a gray box)

[Peter Laidler]

I will drop the 'gauge man', Taffy Txxxxx a line and see what he comes up with.

I think that the L1 rifle part of the designation is just the generic term used by us Armourers as a means of identifying the rifle generally. Like we'd say '...... have you finished the L2's yet.....'.

Talking of L1's and L2's.......... I wonder if anyone has noticed the HELIX ruler. Makers of L2 plastic pistol grips and large batches of the plastic part of the plastic L1A1 handguards