What's the most excessive headspaced No4 you have personally fired?

[Morning Wood]

Very early No4 has one lug (outside) not mating to the receiver shelf. It just about closes on a field gauge with a .632 bolthead. I can cut back the inside lug to make both mate, but it would need to go about .004, but this puts it closing on a field gauge by about .003. I have no hope that I can find a .636+ bolthead.

I'm sure this rifle would have been be culled at a British depot. My question, would you fire as is with only one lug mating, mate the lugs and look for long bolt head before firing, mate the lugs and fire with it closing on a field gauge, or just forget it and make a wall hanger out of it.

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[tbonesmith]

Please read the numerous previous threads on headspace before getting into this. I am fairly sure we don't all need to go around the block with the usual arguments once again.

[Alan de Enfield]

0.636 is towards the bottom end of the size 3 range, I have sold a couple recently that are longer than this, if you are interested I'll measure up the size 3's I've got left.
PM me if interested.

[Peter Laidler]

For one mating locking lug surface I would say definately NO. But on the other hand, if you have two mating locking lug surfaces, there's another side to the story.

I had one that had a seemingly 'perfect' body but every barrel I tried overturned by about plenty of degrees. I breeched it up with a suitably sized home made steel breeching up washer but CHS was about .012" oversize on a No3 bolthead. WELL outside the range of any bolthead in the known universe. I range and accuracy tested it out of idle curiosity on the test and calibration range and it performed as good as gold. I shot it a few times and used it as a good example of how we can be taken in by CHS.

There was a well documented school of thought/fact among Armourers that if you couldn't CHS with all of the bolt head variables and a new bolt, then the induction hardened locking surfaces have gone.

For what its worth.........

But as for

[Thunderbox]

I'm sure that there are many thousands of Enfields out there with asymmetric bearing of the locking lugs, and that the design copes with this asymmetry in the elasticity of the body and the movement of the bolt - or by increased wear on the raised lug, resulting in the bolt fitting better over time. You don't see much evidence that bolt asymmetry causes problems over those thousands and thousands of rifles.

With the early Long rifles, the Army doesn't seem to have worried too much about keeping matching bolts with the rifle - most rifles from that era are mismatched and haven't even been renumbered in service. Perhaps this is evidence that lug bearing (and even headspace) wasn't seen as critical when the design was first issued?


As noted in an older post, I ran a brief series of tests where I deliberately set excessive headspace on several rifles and then observed shooting performance and case behaviour. I don't have my notes to hand, but IIRC I got up to 0.09" gap with the boltheads and rifles I had available. There was absolutely no trend that i could see in accuracy - with a couple of the rifles even shooting better groups with very slack headspace. There were no case separations (mixture of reloads and old military rounds) or other apparent case problems. Of course my experiment was fairly general, and with the rifle being a very flexible system there could be increased influence from other components as the headspace increases.

[ssj]

Buy a new un-stamped bolt for it? I would then try and set this up so you dont touch the original bolt. If it works, restamp it.

I think they are about $30US.

[Peter Laidler]

I'm sure TBoxes points were valid in the days before powerful Mk6 and 7 ammo but I wouldn't be happy about shooting a rifle with just one mating surface. I wonder how anyone would feel about a bolt with just the smaller right hand locking lug mating? Nope....., neither would I.

Maybe I ought to just cut to the quick and say this. If it ain't right, then it ain't right. Or as Mr Ayley used to say. 'Near enough isn't good enough. But exactly right is near enough'

[5thBatt]

Might be a silly question but wouldn't the extractor apply more pressure to the right hand lug as it & the case are the only things supporting the front of the bolt when locked up & ready to fire?
I would imagine the front of the bolt would be pushed/pulled to the right.

[Morning Wood]

I have about 12 No4's that I have rescued from the pound and brought back to their former glory. The only reason that I care so much about this one is that it is a very early 1941 Maltby that was probably made the first week of Maltby production. It's otherwise in really nice shape, all matching, good finish, and no import or export markings. Just like it came from the factory, except a few more wood dings. I wouldn't dare fire it without both lugs making contact with the receiver lug bearing shelf. I think what I will do is to go ahead and get both lugs to contact and hope taking .004-.005 off the other lug doesn't go past the metal hardening, then worry about headspace. I see one fellow above has said he may have a longer bolt head. That is one possible solution.

Peter may be right on this too. I think on this one, someone has removed some metal from the mating surface on the receiver. I have no idea why unless it was to remove a mushroom burr caused loss if hardness. But looking at the bolt lug, it looks like it has never made contact with it's mating surface. There is absolutely no wear on the outside bolt lug. So nothing is making any sense here. If I can get it fixed, I doubt I'll ever fire it enough to mushroom it again unless the receiver is crazy soft.

if anyone wants pic, I can post them.

At this point I need to thank Peter Laidler for all the info he has posted. I learned almost everything I know from reading his posts and articles.

[Peter Laidler]

Thanks for those kind words MC. Just want to pass it all on while I can. In a case like yours, before we ZF'd the rifle we would always try a GAUGE, bolt, inspectors. Check the body against this first.

But to answer 5thBatt's querie regarding the extractor. The answer is that the camming action of the extractor as it rides up the extractor way (and separates itself from the cartridge case by the way) is significantly rearwards.