Breeching up washer

[tbonesmith]

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

Information

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[Bearclaw]

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

[Son]

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!

[arado]

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

[tbonesmith]

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...

---------- Post added at 10:47 PM ---------- Previous post was at 10:46 PM ----------

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

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

[Alan de Enfield]

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" ...

[tbonesmith]

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

[Bearclaw]

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

[Thunderbox]

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.

[tbonesmith]

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

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 ----------

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

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.