Gauge, inspectors, headspace, 7.62 mm rifle

[Peter Laidler]

Seeing the Australian gauges (that I don't recall incidentally either at Unit level or at Bandiana) against the UK gauge, is a good example of the poms complicating things when there is usually a simpler method!

[Peter Laidler]

Just had second thoughts about the Australian idea of taper-rod gauges. It's this..... To use KtK's Aust gauges, you first have to remove the old L/S. And thereby hangs the problem because the L/S isn't an interference fit as such, as defined in engineering terms, it's best described as a friction fit. And removing and replacing them will enlarge the engagement area of the hole by microns each out-in event. Even in the early 60's, worn L/S holes leading to rifles becoming ZF were becoming a problem. That's the reason why L/S's were not only numbered to deal with the WIDTH required to obtain CHS but also identified by the 2x (?) oversize diameter to cater for worn bodies.

If my memory is correct, I seem to recall that the oversize diameters weren't available in the largest number sizes as by then those rifles were already knocking at the door of the scrapyard.

There was no pressure test (so far as I remember) that confirmed that a L/S was too loose although Tankie anmd Skippy will confirm that we used to tap them with a hammer and brass drift and note the dull solid thud that indicated tight one. John Dudley one of the RAEME Armourers devised a simple weight drop-test that would put a weight/load on a L/S that would at least give a quantifiable tightness. That was rejected because it utilised a shock load (albeit a primitive form of.....) whereas.........

Hey......... just watched a USAF Flying Fortress fly overhead. Pure magic, made my day......................... I'm glad they were on our side. Jeepers....... followed a minute later by a Mustang.

But back to normality....., continued...... whereas the workshop method of removal and replacement was by means of a screw press on shaped tools. The screw press was usually a large bench vice! You won't believe this and I never thought that I'd repeat it but I'm sure it'll be in KtK's UK EMER's in the Field and Base section, but at one time in the 60's we were securing L/S's into rifles by clearing and cleaning the inner areas with trichlor, smearing it with Araldite and using that to lock the shoulder in place. Mind boggling or what? Whether that was a temporary repair until the idea of larger diameters came into being I don't know.

But with my engineering hat on, I'd say that better to KNOW what size L/S you need before you try several others. Interesting thread.

Just back outside to fill my Mini Cooper cooling system with a waterless based coolant.

[nzl1a1collector]

I see what your saying .... but if it comes time to use the Australian gauges, then the locking shoulder needs to be replaced and the old one will of been removed since the taper gauges are ..... tapered you can insert them into the locking shoulder hole without oversizing the hole and then do the two thumb test and see which locking shoulder is required size 1 thru to 15. The Australians had 60 Locking Shoulders to select from, sizes 1 - 15 in four different shaft diameters.

I was just reading the EMERs and their solution for loose Locking Shoulders the modification was to enlarge the locking shoulder hole by driving a 0.2998 in. dia. Tungsten Carbide Ball (3110-99-964-5568) (I'm still looking for one of these ) and then using the larger shaft 'Y' marked Locking Shoulders after the hole had been gauged by the L22A1 Plug Gauge.

As to testing for loose Locking Shoulders, the Australians method was to using a spring loaded center punch with a maximum 50 lb blow, may be used. The British method was to "applying maximum pressure to left end of locking shoulder using a large Phillips screwdriver or similar tool".

British Locking Shoulder Press


Australian Locking shoulder Press

[tankhunter]

Yes indeed, Peter's explaination of a Brass drift & 1/2 pound 'Hammer, Armourers,Ball Paign, half pound' was the 'Usual' & quicker method of testing for loose locking shoulders.

Remember, if you are doing a 'Six Monthly', on a ENTIRE Infantry Battalions Small Arms holdings. That is a LOT of Rifles to inspect, Twice a year! Not forgetting All the magazines, Bayonets. Other SMGs, LMGs, MMGs, Mortars, Anti Tank Shoulder Fired Weapons, Instruments, Optical equipments, Etc, Etc........ You get the picture I'm SURE!

ANYTHING that would speed your workload safely & efficiently. Would be utilised, even if it was not an 'Officially Approved' method. as long as it did not/ would not damage the equipment.

And more importantly, was SAFE! Mind you, there was a limit to what one could do!....call it 'tricks of the trade' picked up & learned from more learned Senior collegues at the at time.
And incorporated in your own work, out put executions!

Removing a locking shoulder with pressure was fairly easy. you NEVER, EVER drove one out with a Drift/ punch!!!! They were so hard, they would/ Have seen them, shatter!!!

A Ball bearing was placed on the left side of the locking shoulder. In the concave portion of the cross shaft. Then, pressure could be slowly applied to this B/Bearing. & the shoulder would slide in until seated.

Pete, regarding Aircraft over your domicile. We have a privately owned small grassed Airfield up the road. Owned by a Millionaire. He regularly fly's either His Spitfire or Mustang (Oh, the Agony of choice!) over my own House. Only when the weather is good/ dry. Usually late afternoons, or at weekends. & sometimes on both days at the W/End.
We are spoiled!
Oh, the sound of those Merlin Engines, so distinctive. I never tire of hearing them!

[browningautorifle]

A Ball bearing was placed on the left side of the locking shoulder. In the concave portion of the cross shaft. Then, pressure could be slowly applied to this B/Bearing. & the shoulder would slide in until seated.

These word pictures are priceless to me, having examined FNs from one end to the other during the countless hours of boredom and drudgery involved while holding one for one reason or another. I can see it all...

We have a privately owned small grassed Airfield up the road. Owned by a Millionaire. He regularly fly's either His Spitfire or Mustang (Oh, the Agony of choice!) over my own House.

I remember as a kid being out in the back schoolyard at home and hearing an engine far above me looking up...to see a Spitfire Mk 9 doing a slow barrel roll. I looked around to see no one else was aware... Years later I watched it at an airshow in Windsor Ontario, still resplendent in UK battle colors, owned by a millionaire there...

[Peter Laidler]

It gets even better (see thread 12). Just watched a white and grey RAF Catalina flying low in the opposite direction to yesterdays Fortress and Mustang. Fantastic. Mind you, not so fantastic if you are a local U-Boat commander.

[browningautorifle]

a local U-Boat commander.

Got many there? You have U505 over at Birkenhead(?) beside the Mersey. We have the odd one around, an ex Artyman...a Tiger commander (died recently) and a Fallschirmjäger Lt...also just recently deceased.

[Peter Laidler]

I blame Kevin the Kiwi. Why does he keep throwing these low-ballers in that test the old memory banks going back years and years

[browningautorifle]

I had to look back to see what the thread was about...

[mrclark303]

U534 Jim,

Now cut into sections and moved unfortunately, I had a tour of "Das Boat" back in 1998 when she still complete, a quite remarkable privilege to see and tour such a rare (and very intact and structurally sound) survivor of her type.

The Conning Tower was rebuilt by the apprentices at Camel Lairds. She was highly controversially cut up into 5 pieces in 2006 and moved to a new site when The Warship Preservation Trust was closed due to development of the site they occupied.

Two sections were displayed with Plexiglas panels covering the holes apparently .... So it definitely wins the "Who has the biggest instructional Cut Away" competition!

Sorry to throw the thread even further into the long grass!

---------- Post added at 04:34 PM ---------- Previous post was at 04:30 PM ----------

If it's a one off, rare as hens teeth L1A1 related component of accessory, you can bet Kevin's got it, or its on his hunt down list!