Lee Enfield No4 Mk1 Longbranch

[Alan de Enfield]

Yes the bolt head is a number three length, at one time they were making flip up sights because they were trying to get the rifles out as soon as possible during war time to speed up production.

I thought it looked like a No3.
That would indicate it has probably had a pretty hard life.

If you are successful it would be worth paying particular attention to the headspace, if a rifle is fitted with a No3 bolt head it is normally in the last stages of its life.
Base workshops, or the manufacturers (for example during FTR) were not allowed to send the rifle out with a No3 bolt head, they were only fitted 'in the field' or, on agreement from a Senior Examiner to 'keep the rifle going a bit longer'.

An old post (2008) by Peter Laidler :


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.

There is a little more you might need to understand before you can appreciate the whole picture. The No4 rifle was a very precisely made piece of gear. The very fine production tolerances achievable meant that every rifle could be assembled with any parts from production within set tolerances and be correct for headspace with either a No0 or a No1 bolt head fitted. To leave the factory, that was between .064" and .068" headspace. If a rifle failed headspace in service (failed the "field" gauge at .074") Then it was sent back for repair. If it could be headspaced with the next size bolt head (either a 1 to replace a 0, or a 2 to replace a 1) it was deemed good to go. If a rifle did not pass headspace with a No2 bolt head, then it was passed up the line to the senior inspector who would apply the Gauge, Inspectors, Selected Breach Bolt. If the receiver passed the test, it could be fitted with a No3 bolt head and put back into service.

NOTE HERE. A NO3 BOLT HEAD WAS ONLY TO BE USED ON THE SAY SO OF THE SENIOR INSPECTOR.

If it did not pass the test, it would have been sentenced Z for return to the factory, (even if a No3 bolt head would pass headspace)
Interestingly, I wonder how many rifles are out there with No3 bolt heads in them that the owners have fitted to keep them in headspace, when actually the receivers may be worn beyond reasonable limits.
Also I wonder about the amount of rabid buying in the past of number3 bolt heads and the owners who have fitted them because their rifles failed the SAAMI spec field gauge at .070", which is a good .004" below the manufacturers spec...
I would suggest, short of panic, anyone who has a No3 bolt head in a No4 or No5 rifle should own a .074" headspace gauge and check the rifle every couple of hundred rounds. If the hardness has gone (or becomes too thin from ongoing use) from the locking shoulders, the headspace will increase as the softer metal is extruded by the forces of firing. Checking and finding it failing with a No3 bolthead that passed a hundred rounds ago will tell you things are not right.. time to retire the rifle. NOT REPLACE THE BOLT BODY!

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.