Breeching up washer

I have needed a .075" breeching up washer for a No4 7.62 barrel, but after some have been back and forth to England and I've still not found one and I can't get one, and I got over it. I thought I'd get a tool maker to do one for me but I thought instead I'd make it myself. It will be good practice on my lathe and I'd make some new tools.
Any way I used a flogged out No4 barrel, so I suppose the materials the right stuff. It took ages, but next time I'd do it a lot quicker.
I was after .075 but got .080 thickness so if necessary I'll just relieve the barrel shoulder by .005", and that should also help to keep the washer held centrally, we'll see.
Anyway I'm glad I took the time and did it, after all I bought the lathe to make this sort of stuff. Here's the process:

Attachment 18176 - Attachment 18174 - Attachment 18173 - Attachment 18175 - Attachment 18172 - Attachment 18177

Tom looks like I now know where to go for my breeching washers. Great pictorial instruction.

interesting... I didn't know the No4 was shimmed on the front face of the receiver ring. (my very limited No4 knowledge showing again...)
The shims to index a No1 barrel go on the end of the barrel, not the knox. They used to be available in either .002" or 005". I would have thought they'd do the same job for the No4... comments?

Thanks for the post, Tom... and good work!

I use breeching washer for L1A1. Surface grind to need. Gary:thup:

The No4 holds the tension on the receiver ring, the no1 on the face of the tennon. This barrel is a weird setup I haven't seen before, where you [I]need [I] a substantial washer to affect proper indexing, not a couple of thou, but 75. There were 2 washers supplied with the new barrel totalling 70 thou and while the barrel would index and headspace with these washers there simply and absolutely wasn't anywhere near appropriate tension on the barrel/receiver, though it was somewhat firm. So that's how I got to this...

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Originally Posted by arado

I use breeching washer for L1A1. Surface grind to need. Gary

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I did my best to track some down, but could only lay my hands on .060 washers, and i needed more...

A couple of of Peter Laidler's old posts on breeching up :

Index of Peter Laidler's on-line series of articles.......

About 1/3 the way down in Peter's index of articles titled "Breeching Up" ...

I decided that I didn't want to use the last washer I made using the barrel, as the diameter was slightly smaller than that of the breeching up washer fo the L1A1 or the No4 one I had for reference.
So I bought some 31mm diameter medium carbon steel round hollow bar, and using the same method as above I made some washers, the same except for having an OD of about 30mm which is very close to the diameter of the shoulder of the No4 barrel.
I could not control the width of the washers precisely, as they always came off the lathe bigger than their measured width before releasing them from the bar by boring out the centre. I have no Idea how that worked, but it was how it was.
So I clocked in the barrel in the 4 jaw, and centred the breech end in a live centre(which centred, I checked), then using the compound slide I could take precise cuts off the shoulder, which also served to centre the washer.
Anyway, this was my first go at more than one of these operations, but I am posotive that the result is right.
The barrel is now correctly indexed, and extremely tight. It's taken me ages, but I'm finished for this portion of the job.
I suppose I next need to fit the 7.62 enfield mag, but I might get help there as I don't want to stuff anything.Attachment 18245Attachment 18243Attachment 18244

Tom, that grey sure does show up against the black. How did you overcome the tapered barrel sitting in the chuck without it slipping.

Myles

Why do you need to use a breeching up washer for a military-profile (eg 303 profile) barrel? Those .303/7.62mm barrels were designed to fit the same as a .303 barrel - without washers. I've never seen a washer used on any of the converted No4s I had through. Only the heavy target barrels were supplied with a set of washers.

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Originally Posted by Thunderbox

Only the heavy target barrels were supplied with a set of washers.

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So I thought too, but hey, here's one that's an unused standard profile 7.62, supplied with a set of washers, that needed a little bit more. What more can I say?

---------- Post added at 06:34 AM ---------- Previous post was at 06:31 AM ----------

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Originally Posted by Bearclaw

How did you overcome the tapered barrel sitting in the chuck without it slipping.

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It cant slip into the chuck because it tapers up towards the breech, and it can't slip out of the chuck because of the live centre supporting the breech end.

The last No4 Parts list illustrates breeching up washers for the No4 Mk2's. I have just spoken about this to Sgt Rxxx Sxxx and he's confirmed that many from the RAF ACF's and CCF's (Cadet forces) that went through the main workshops had them. This indicates to me that they will be the LATER Mk2's (maybe the UF's). The breeching up washers were not codified (didn't have part numbers) so they had to apply for them. They had them in stock as they used the L39/42's as required or for an odd size, machined up

Last night and tonight I fitted the mag, a new 7.62 extractor, extractor spring and suitable bolt head, and with a little adjustment, the rifle feeds and reliably ejects without milling the receiver, the second ejector screw or the mags ejector tab (missing)
I left the bedding as is for the moment (centre bedded by AGP), it appeared to be just right anyway and the rifle used to shoot fantastic before the barrel went completely. If it needs adjustment after range testing I'll look at it then.
I've wanted one of these for ages, and I've only seen one or two but now I've got a sweet No4 Mk2 in 7.62 with a new barrel and mag in a sound unit. Looks good too, I'll let you know how she shoots!!

I love it when they're back together!

Attachment 18319

Tom, She looks great.
I bags a shot of her when I get down your way in the new year. What sort of mag are you using with it.
Myles

it's an enfield mag, I think it's one of the copied bodies with an original follower, as there are no mag body markings. You're welcome to have a shoot when you make it down here.

The Enfield 7.62mm barrels and later .303" barrels had the shoulders cut back to accommodate a thick breeching washer used to control breeching up by the 'constant torque' method. There is a very good account of this on page 185 of 'The Lee Enfield Rifle' by E.G.B. Reynolds (long out of print).
As I recall, (from watching the operators doing it) the breeching washers came in thicknesses of about 0.060" to 0.080" in steps of 0.001". A thickness of 0.074" would be typical. At RSAF Enfield they selected the thickness which would allow you to screw the barrel onto the body hand tight, leaving a further 18.5 degrees 'breeching-up angle' for tightening to the vertical position with the breeching up wrench. The torque required to do this should then be 120 +/-5 lb-ft.
This was a post-war development because it was thought that slightly bulged chambers were resulting from some barrels being over stressed by having to be screwed in with an excessive amount of torque because the breeching up angle was too high.

Quote:

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Originally Posted by enscien

The Enfield 7.62mm barrels and later .303" barrels had the shoulders cut back to accommodate a thick breeching washer used to control breeching up by the 'constant torque' method. There is a very good account of this on page 185 of 'The Lee Enfield Rifle' by E.G.B. Reynolds (long out of print).
As I recall, (from watching the operators doing it) the breeching washers came in thicknesses of about 0.060" to 0.080" in steps of 0.001". A thickness of 0.074" would be typical. At RSAF Enfield they selected the thickness which would allow you to screw the barrel onto the body hand tight, leaving a further 18.5 degrees 'breeching-up angle' for tightening to the vertical position with the breeching up wrench. The torque required to do this should then be 120 +/-5 lb-ft.
This was a post-war development because it was thought that slightly bulged chambers were resulting from some barrels being over stressed by having to be screwed in with an excessive amount of torque because the breeching up angle was too high.

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But that was approved in 1956, long after No4 production had ceased - which is probably why such rifles & barrels are rarely encountered.

That's

Quote:

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Originally Posted by enscien

The Enfield 7.62mm barrels and later .303" barrels had the shoulders cut back to accommodate a thick breeching washer used to control breeching up by the 'constant torque' method. There is a very good account of this on page 185 of 'The Lee Enfield Rifle' by E.G.B. Reynolds (long out of print).
As I recall, (from watching the operators doing it) the breeching washers came in thicknesses of about 0.060" to 0.080" in steps of 0.001". A thickness of 0.074" would be typical. At RSAF Enfield they selected the thickness which would allow you to screw the barrel onto the body hand tight, leaving a further 18.5 degrees 'breeching-up angle' for tightening to the vertical position with the breeching up wrench. The torque required to do this should then be 120 +/-5 lb-ft.
This was a post-war development because it was thought that slightly bulged chambers were resulting from some barrels being over stressed by having to be screwed in with an excessive amount of torque because the breeching up angle was too high.

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That's very interesting, and .074/.075 is what I judged I needed too. 120 lb-ft is far less than I would have thought necessary, and probably far less than Ive got on. I'll have to get my torque wrench and get a feel of how much 120 lb-ft is. Anyway it's not coming out, but you learn new thing about this all the time.

Got this bad-boy to the range today to run in the barrel, and run some hot loads through it and get a zero. No issues with developing headspace, no signs of excess pressue with the hottest load, and with a bit of hassle a solid starting zero for 100m. Small targets and grass butt stop made it a pain to get on paper.
No world records for the initial groups but at 3-4 inches for the first 5 shot group off a makeshift box/rest I'm pretty sure I can develop a load or tune the rifle as required to make it a very competitive piece for the year of upcoming competition. It will do for a start anyway.
Happy it appears properly functional and sound.

Made a very small adjustment to the bedding and got to the range today and zero'd the rifle at 300m. All looked good. Then I shot a 5 shot group, all inside the V bull in a nice round 4" group. Beauty! I have a very competitive rifle for this year.

Tbone,
Update on the barrel, it came from Lawance Ord. They might be able to fill you in more of it's origins.
Myles

Interesting, when did he sell it?

A few years back, he purchased it to replace the 25/303 barrel. I think they were going for 99 bucks each then. Sure the guys at Lawrence will know the barrels and their origin. I remember seeing the ad for them and they weren't the Paki or Indian made ones, as you can see by the quality. I do recall Ligthgow producing a large quanity of No4 barrels in 7.62, that would explain no markings on the barrel maybe.
My mate did mention that it came wrapped in the orginal paper, but can't remember the info on it. At least it is some sort of lead.

Myles

It is marked with a Lithgow code AY or AX, I forget, and it has a Lithgow proof. No question it's a Lithgow.