No. 4 Longbranch Barrel Removal Secrets

[Centurion]

Does anybody have any secrets they'd share regarding a pain-free method of removing the barrel from Longbranch Actions? For some reason they are always torqued on so firmly that they require risking damage to the action simply removing the barrel!

Information

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[Peter Laidler]

Never had a problem with any of them except when unbreeching one with a slave bolt and head in place which was standard practice. UNfortunately there was an extractor in the bolthead I screwed into the bolthead I opted to use............... Destroyed the rifle and barrel! But it was an Army rifle so it didn't matter toooooo much! Called learning from experience.....

Just lean on them and while some might be tight, they will all go providing that you've got the right kit............

[Centurion]

Yes, the barrel taper and the knox form make for difficulty holding the barrel in the vise. I have a good, close-fitting action wrench, so the biggest problem is to keep the barrel from slipping in the vise. I'm going to make a custom set of vise-rings with Brownell's Steelbed set in the aluminum ringblocks. That should do the trick!

[Bruce_in_Oz]

The barrel vise fittings sold by Brownells are pretty good, BUT, will not get a "tight" No4 barrel out.

It depends, of course, on what you want to do with the "old" barrel. If is headed for the garden to hold up the tomato plants, then it doesn't much matter how much it is abused to remove it.

The "time-honoured" method involved making a cut around the Knox Form of the barrel, about 30 thou forward of the receiver face. This face is the surface against which No4 barrels are breeched, so, you don't want to mess with it.

This "relief" cut SHOULD release the loading on the shoulder. If the barrel is also "rusted in", you may still have a job a head of you

If you are removing a GOOD barrel from a rubbish receiver, this method is a LAST resort. Yes, as others will tell you, it is not difficult to machine up and fit a breeching washer a la a certain 7.62 conversion, but it is just more work. If you don't have the machinery or the skills, it could become expensive work.

Caveats: As the receiver (body) does not have the handy, large, flat bottom, of the likes of a P-14, there is not much on which a receiver wrench can gain a good hold. This is where a lot of good bodies are wrecked. If the wrench or other tool you are using is not a VERY close fit to the circumference of the receiver ring AND the "lumpy bits" at the bottom, you risk damaging the receiver, especially the threaded boss for the front trigger-guard screw.

The whole barrel swapping caper is fraught with "excitement. Let's say you get a "good" barrel out, relatively intact. You may well find that when you gleefully wind it into a used, but good-looking receiver, it comes up to alignment by hand power alone. This is not good, as you need to apply torque to get the barrel to a point where it won't wind itself out again.

Part (if not all) of the problem is :thread crush". When ANY threads are engaged with "excessive enthusiasm", the metal on the flanks of the threads essentially goes from an "elastic" to a "plastic" state; i.e. it compresses and does NOT spring back. WHEN this happens on a rifle, the thread is no longer precisely "clocked" to the datum point on the components and the barrel will OVER_TRAVEL in the breech thread and not line up properly when correctly torqued.

This phenomenon was known well before No4 times. As I understand it, Lithgow only made their No1 barrels with one thread "standards" and that was to suit a gauge for which I have no numerical reference. I have not seen the drawings for the "Heavy" barrel so have no idea if they made any such provision.

However, some bonus nerd info: When Lithgow made barrels for No4 rifles used for "club" shooting, they did two things.

1. Deleted the bayonet lugs.

2. Made "Replacement" grade barrels with a breech thread offset of between 10 to 15 degrees. That information is lifted straight from drawing U-52831, 12th March, 1965.

[Peter Laidler]

Ah............. that's where the experience of Armourers who have been doing this since pontius was a pilot comes in. The unbreeching/breeching up kit WE made and used - as opposed to the kit supplied - had the BODY clamped in the jig, facing upwards and the tapered/pegged barrel spanner will slide down onto the barrel. Knock the barrel spanner onto the barrel using a lead or rawhide mallet to form a taper lock then drive in the actual locking segment. That way we rotated the barrel from the locked down body

NEVER failed yet! In fact, as I said above, it very nearly allowed me to unwind a barrel that was solidly locked in with the extractor!

[jimmieZ]

The "rotating the barrel with the action locked down tight" is the same method I've used in barreling the 15 or so L1A1 and FAL's I've built in the last 15 years. As stated - it works every time.

Jim