Criterion No4 barrel

[Rwsgunsmithing]

Before I get to far I need to be clear here.

1- These are prototype barrels and by no means are they the final rendition or finish product that Criterion will be selling. They sent a select few a barrel or two to check out and get some of the bugs worked out.

2- I have saami spec headspace gauges. Brian over BDL pointed out to me that I need to be using a .074 gauge. So I added a few pieces of tape to the back side of the nogo to get me out to .073. I know it's not the most precise method but does work in a pinch.

The chamber must be finished cut because with the action in place and checked with a headspace gauge (.073) it starts to close but doesn't go all the way and this is with a #0 bolt head.

I'm honestly going to suggest to Criterion they need to make it so the barrel is under indexed more and allow the gunsmith to chuck up the barrel in the lathe and face the barrel back where needed. I really feel they're going to have a bunch of headaches with customers out there who think this will fit and index on there action right out of the box and it's a lot easier and cheaper to just have to set the barrel back then to find and purchase some breeching rings. Your thoughts?

[Brian Dick]

Peter is exactly right about learning to "feel" them after doing enough over time. The ability to select fit bolt heads and barrels is such a pertinent part of working Lees. Unfortunately, most of us don't have a large supply of either to select fit from. Because of this, a happy medium will have to be adopted in new barrel production. It will entail skimming the shoulder on the barrel to bring them up to 17 degrees if the under turn is excessive. The only option for overturn are using correct breeching washers which I've already discussed with Criterion and they can probably make them in house. I was asked if there a list out there somewhere of the sizes that were used on the 7.62 L8, L39, L42 and commercial variant conversions as done at RSAF Enfield?

Does your bolt close on the .064 GO gauge Robert? Unless I'm misunderstanding, from what you posted here the gauge starting to close on .074 NO GO, (.073 in your case), but not closing all the way is perfect. The .064 Gauge must pas too and "Bob's your Uncle".

I have two of the barrels here gents. I'm sorting them out too but haven't installed one yet. I have one dedicated receiver with a matching bolt that I'll use to build a rifle and test both barrels thoroughly.

[Rwsgunsmithing]

Yes it does close on the .064 go gauge.

The problem with the breeching washier is the barrel will still have to be set back (if done per Peter's article) anyway. So why not just add, say 20 thou to it and allow the smith to remove what is needed.

If they decide to make washers what sizes will they do? Are they going to try and do a .010 washer or thinner? I think there asking for trouble doing that. I also feel they're trying to do "too much" with the barrels and trying to make them work on too many of the receivers out there when in fact they might actually only work on less than half.

[Peter Laidler]

On the other hand, why not use the selection of L1A1 rifle breeching up washers readily available. They're the right dia and hardness too I'd have told them all this for the cost of a call!

[Rwsgunsmithing]

But you would still have to face the barrel off anyway.

Unless they plan for you to use the washers and push the shoulder forward more so that you can buy a small assortment of washers and index that way.

It would work but would require you to find and buy a assortment of them. Doing a quick search I only found a couple of places that offered any washers and some sizes weren't even in stock.

[Bruce_in_Oz]

A LOT depends on the accuracy of the thread "indexing".

As I also understand it, there were "new" barrels and "replacement" barrels. The difference was an offset in the thread "start" by several degrees to allow for "crush" of the breech treads / body face that occurred during the "factory" barrel installation".

I have seen the note on a barrel drawing; just trying to find it.

As for "short-chambering": The .303 is a rimmed case, the most important thing is to have the rear face of the threaded tenon in such a position that it provides the correct "headspace" with a "correct" body, bolt and preferably a No ")" bolt head.

The No4 breeched up (for torque and "indexing") on the FRONT face of the body. If that surface is awry in any way, all bets are off. Earlier patterns of Lee Enfield breech up INTERNALLY, using the rear face of the TENON engaging the inner collar at the rear of the thread in the body, just like a Mauser 98 is SUPPOSED to.

If you have a No4 body that has "defects" on that front face, you have two choices:

Put it in the scrap box,or,

Mount it on a close fitting mandrel that has a thread to engage the body, and face off said body in a lathe, like the custom rifle folk do with errant Remington 700s. (After they ensure the threads are within tolerances, of course). THEN you may need to start looking for breeching washers or a custom barrel. How much do you want to spend?

[Bruce_in_Oz]

Back from the "crypt"!

An interesting Oz connection.

Drawing No. U-52831, Issue 8. Drawn by K. Sankey, 12 March 1965. (Reason for redraw: Chamber re-designed (Bullet Leede. (sic)).

This is a drawing of a VERY post WW2 barrel for a rifle that saw rather limited service in Oz.

Bayonet lugs are NOT shown in the drawing. Thus these barrels are NOT for "Service" use, but for the Rifle Clubs, which, at the time were still very much a part of the "heirarchy" of defence: (Regulars, CMF (Reserves) and Rifle Clubs), as defined by the Defence Act of the time.

Anyway, there is a "note" in big, bold text that states:

FOR ALL REPLACEMENT BARRELS, POINT 'A' MUST BE RETARDED BETWEEN 1O DEG AND 15DEG TO COMPENSATE FOR BODY DEFORMATION.

The datum (point "A"), for the breech-thread start is defined as follows:

A point on the breeching shoulder, 10deg, 8min above the horizontal, on the RHS of the shoulder and at the major diameter of the thread.

To whit:

Major Dia. 1.000 / 0.9937 " dia. CREST OF THREAD TO START AT "A".
FORM: WHITWORTH.

So, this is NOT a "service" barrel, but I doubt very much that its specifications, apart from the deletion of the bayonet lugs, would deviate far from anything produced in Canada or Britain.

Has anyone ever seen a drawing (or a sample) for a "service" barrel with the provision for thread-start "variation" in Canada or the UK?

[ireload2]

Following an armorer's processes for fitting a one size fits all barrel to a box car full of old receivers is not going to work.
Sure you can shim or use headspace rings. Why not buy a barrel with an extra .040 or so of shoulder?
Oh the headspace might be off? Well it might be off anyway. Fix it with a chambering reamer and bolt heads.
You will get a better installation if you can use a mandrel through the bolt race to permit facing the receiver off square to the threads.

Large numbers of components and the use of a scrap bin allow armorers to swap parts and fix most problems at the tax payer's expense.
These new barrels are being funded by many individuals that have to make one barrel work on one rifle. You will probably need a lathe...

[Peter Laidler]

This new barrel project is simply making a mountain out of a molehill. The answer really is very simple, believe me......, having breeched up one or two No4's and 5's in my life. All hold fyour fire (if you'll excuse the pun.....) for a while. I am in discussion with the makers now and the answer is being implemented, probably as we speak...........

[bigduke6]

You will probably need a lathe...

I would say " certainly need a lathe plus the finish reamer"