Safety catches on SMLE's and No4's

[303Guy]

Good point. I must say the safeties do hold in the fire position quite fine. There is a strong detent action on drawing the safety back into safe. The just move forward fairly easily - easier than rearward. They don't flop around or anything. The worst is they get bumped forward by clothing or whatever brushes against them.

[ssj]

No4 safety parts at least seem very readily available and fairly cheap. For myself generally I look at a part and if it looks anything more than having minor wear I replace it, especially on anything safety. Then as an engineer I know if I get it wrong injury or death may result. I dont want to die, get injured or go to jail because someone else does, I want my *** to stay single purpose...... Having had the UK health and safety executive inspector all over it one time checking the steam reticulation system was well maintained and safe due to an injury, trust me its not somewhere you want to go twice (I was faultless btw).

[303Guy]

I'd rather it be in good order even if I don't use it. I might have the need for it sometime.

[Bruce_in_Oz]

Safety; safety check:

Is the spring still "springy?

Is the spring held properly in place by the screw?

Is there a deep groove worn in the lever, either side of the detent hole?

Is the tiny "driving flat" on the tip of the locking bolt portion of the lever assembly worn?

Is the safety catch proper (the threaded ring and stick thing that threads onto the lever) worn or damaged?

If on a SMLE, is the "washer" with the "V" notches in it in place between the spring and the lever? This little washer is a leftover from earlier days and is basically a stub of the old "long -range" volley sight arm. Hence, on a SMLE, the "detent" function is provided by the hardened pins in the receiver, whilst on a No4, this is more simply achieved by notches in the lever and a new, horizontally mounted spring. Many late-production Lithgow safeties have a washer that is "notchless"; seems sensible, once the volley sights were "out", there wasn't much point in the detent notches: Even less point if a plain, flat spring were fitted.

NOTE: Whilst SMLE and No4 safety components may look similar, ALL of the components are different. Not only the shape changed, but even the multi-start thread (that serves to drive the catch in and out as the lever is manipulated), is a slightly different diameter and form, just to confuse the unwary.

[Peter Laidler]

The EMER states that the safety catch part is interchangeable Bruce.......... Mind you, it's a bit ambiguous the way it's worded....... Is it? Or not? I'm not sure about Paul's idea of re-bending the safety spring. I would be more inclined to anneal, harden and re-temper in order to retain its ORIGINAL properties. Or just replace with new

[breakeyp]

The EMER states that the safety catch part is interchangeable Bruce.......... Mind you, it's a bit ambiguous the way it's worded....... Is it? Or not? I'm not sure about Paul's idea of re-bending the safety spring. I would be more inclined to anneal, harden and re-temper in order to retain its ORIGINAL properties. Or just replace with new

I have done it successfully three or four times. If you do it too hard/fast and it breaks, you probably need a new party anyway. You can't do it with the No.4 rifle flat spring. Peter, new parts are nice but I didn't have HM Govt endless supply depot available. best, p.

[Bruce_in_Oz]

"Ambiguous" is a good word.

I dug out my small boxes of of both sorts of "bolt, locking" and" catch, safety" to play mix and match.

The "major" diameter of the locking bolt threads averaged out at:

No1: Mklll 0.270"

No4: 0.268" Mostly Canadian "boot" shaped specimens.

The No1 "catches" will easily run on the No4 bolts, but are a little wobbly. They would function OK on a rifle.

The No4 catches seem very reluctant to even start on the No1 locking bolt threads. I suspect the MINOR diameter of the threads may be the problem. A quick measure of the minor diameter of the thread in the catch itself gives:

No1: 0.254"

No4: 0.235"

And I have no way of measuring the form angle of the thread! Any metrology buffs out there?

Most of my small collection of No1 minor parts, like safety components, sundry screws etc., are still in their factory "grease', whereas my No4 parts, with the exception of a few small packets of extractor springs and screws, are "pre-loved".