A hopeless case?

[browningautorifle]

If it is never going to be a restorable / collectible rifle, have fun making the best of someone else's bad job.

I'm not going to sink anything into it. It works fine and eventually someone else will have it.

I'd have thought it not too difficult to restore back to military trim, if that was the aim. Needs a new FH of course,

Not the plan at all, a new FH would be unobtainium. I have a plan to produce them if it proves viable to ship them. We'll see. This one is as is.

a solidly fixed L1A1 flash eliminator

I suppose...but I don't have one. This one was simply sawn off in the small of the cone and the bayonet lug hacked. The pins were then driven in from opposite sides. I had to remove it, which came off easily and then clean it up in the lathe. These sights shoot correctly and will suffice. The trigger was one stage because the woodwork was out of whack, now good. All I need to restore it is all the wood, the handguard ring, a new F/H and pins and we'd be away...

[Bruce_in_Oz]

No1 and No4 / 5 barrels have the same nominal breech thread diameter and pitch.

HOWEVER.................

The No1 thread has a very "Enfield" form, sort of a cross between Whitworth and BA, with radiused roots and crests, etc and a unique "form".

The No4 / 5 breech thread is pretty much a "standard" BSF recipe.Yes, you can wind a No 1 barrel into a No4 body and vice versa, but, as engineering practice goes it's one of the versa vices.

Furthermore, No1 barrels breech up on the INNER breech ring of the body, exactly the same as Mausers are SUPPOSED to do.

In the spirit of “casual” engineering, almost EVERY “commercial” replacement barrel for Mausers, breeches up via the barrel “reinforce” shoulder and the front face of the body. Even worse, they are almost ALWAYS cut with a sixty degree form, as opposed to the correct fifty-five degree, very British Whitworth form, complete with radiused roots and crests; not exactly Kosher.

No4 / 5 rifles breech up via the Knox-Form shoulder and the front face of the body, a la a Remington 700.

[browningautorifle]

And...a #1 barrel will likely come exactly upside down when it comes tight on a #4 or #5 I think. The barrel on this one is serviceable, shoots to POA at 100 so it'll be fine.