Gauge Inspectors Selected Breech Bolt No1 Rifle

[Thunderbox]

Came across these, mixed in with some bolts.

Maybe someone has to hand the excerpt from EMERs describing their correct usage?

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.

[Brian Dick]

Nice, for gauging the bolt runway in the body when new or worn I assume? Peter!!

[Roger Payne]

Very nice find Thunderbox! I've never found one in all these years, although I do have the equivalent for the No4 rifle.

ATB

[mike1967]

Very nice, and in good condition. Never seen one before.

[Peter Laidler]

I'll explain it tomorrow...............

[Peter Laidler]

GAUGE, inspectors, selected breech bolt......... Haven't seen one of these for a few years. Yes....! Only used by the most senior examiner, this bolt was a calibrated bolt made to the EXACT size. It was kept in an oily drawer along with the other gauges. It's main use was as the final arbiter as to whether a body was worn out. I seem to recall that the No1 gauges came with a matched bolt head which your are missing (oh no they're not, I've just looked properly......!) The locking shoulders were specially hardened so NEVER use one of these bolts as a true bolt and the distance between them and the face of the bolt was the datum. When it was impossible to get CHS, using the old bolt and boltheads then a new bolt, you'd use the gauge bolt do the final check. If this failed then the rifle was scrapped as this calibrated bolt had deemed that the body locking lugs were worn through.

The No4 bolt didn't come with a bolt head as a matched set BUT there was a special bolt head to be used with it that was a special measurement that I forget at the moment. This did the same thing.

This gauge bolt also dictated wear in the boltway. For example, the smaller left locking lug MUST clear the nose of the sear when loading and unloading. If it does foul, then the gauge bolt is used to verify that the body is worn and not the new bolt. This test should be carried out with the bolt lightly pressed down towards the sear nose to give an accurate assessment of the condition of the body. Obviously, it could also be used as a gauge to test other worn bolts too but in those cases, we had the 'inspection standards' specifications to refer to.

Alas, the same bolt was used to gauge L42 bodies too and these were all getting quite old and as such, some would fail the worn body test so you were allowed to put a line punch mark across the sear stop in the body to lower it very slightly........., JUST sufficient to allow it to clear the gauge bolt small/left side locking lug. But this line punch 'allowable bodge' could only be used once. After that, you were permitted to take a gnats knacker off the apex of the rounded surface of the rifle bolt................ But the days of the service No4's and L42's were numbered.

Off the subject slightly............. I'll continue on the next thread.........

[Peter Laidler]

The gauge bolt was also used as the condemnation level for other things, apart from being scrapped. DP for example! The gauge bolt will also tell the Armoutrers whether the body locking lugs are worn unevenly or whether one side of the rifle bolt has run through the hardened shoulder. The rifle will still function perfectly and is suitable for training but NOT for service use.

Anyway, there's a few examples of how the GAUGE, inspectors, breech bolts were used. Kept by the senior examiners, calibrated initially by the Chief Inspector of Small Arms at Woolwich (the CIA mark) and then annually or so at the calibration laboratory,

There, yet another few bits of useless Enfield information. Next question................

[jss]

There, yet another few bits of useless Enfield information.

Why useless?. This is excellent stuff and surely exactly the sort of technical detail owners and dealers must think about and need to know so that they can ensure their rifles have not crept into the DP zone!.
How are these things determined now in the absence of these and presumably other similar gauges?.

[Bear43]

There, yet another few bits of useless Enfield information. Next question................

Peter, please don't think of any of that info as useless. I am quite thankful for everything that you and so many other knowledgeable people share with us. I enjoy reading all this info. I love knowing not just about the rifles I own but how they were cared for, inspected, and repaired when they were in service. For me it's all part of the rifle's history and I am quite happy that you are willing to fill in those bits for those of us that wouldn't know any different otherwise.

[jss]

Could a New(ish) No4 bolt be used on No4's as a substitute to some degree?. i.e. would they be manufactured to the same tolerances.