Issue with SMLE barrel

[Aussie48]

Grab some Australian made Woodleigh .312 174gn Weldcore PP SN cat number W68A, they are flat based and work in my No1 which has lets say a non pristine barrel

[Patrick Chadwick]

All the basic elements of this problem have been mentioned here and there. Cordwear certainly does exist. Crowns get beaten up by steel cleaning rods. Throats erode. And bore profiles wear. And I have experienced more than one rifle with a tendency to send the bullets sideways through the target.
But they were cured.

1) You can't put back the metal on a worn throat or rifling. But you can have the crown cleaned up for a few dollars. Not counterbored, but just cleaned up a couple of tenths of a mm or so, so that there is a continuous bright ring around the muzzle allowing the bullet to exit without any off-centre thrust.

2) You can compensate for the wear by using a bullet with the largest diameter that can fit the case neck and bore, with the longest bearing (i.e. cylindrical) surface that you can find. So flat-base is better than boat-tail in worn barrels.

If you can get them, buy some of the Hornady type 3130. Flat base, long cylinder, round nose. For me, they turned a keyholing Mosin Nagant sniper into a 1 MOA precision rifle. And an Argentine Engineers Carbine that not only keyholed, but didn't even get all the shots on the paper at 50 meters, into a usable rifle that at least hit the black reliably at 100 meters.

Of course, this all implies that you will have to get into reloading.

---------- Post added at 10:52 PM ---------- Previous post was at 10:50 PM ----------

a rebarrel looks to be the order of the day.

Only if you refuse to reload.

---------- Post added at 10:55 PM ---------- Previous post was at 10:52 PM ----------

so I'd like to think a pull-through would be like a gentle massage by comparison)

Not so. The pre-Columbian civilizations of Central and South America cut huge stones for dry-stone walls using ropes bearing abrasive - just like old gritty pull-throughs, in fact!

[Colonel Enfield]

Well, a recent range trip seems to have confirmed the bore has had it, alas.

A friend kindly made up some reloads with LRN projectiles (flat based) in diameters from .314 to .316 and the results were not encouraging.

The .314 projectiles were terribly inaccurate AND keyholding while they hit the target, whilst the .316 projectiles were just terribly inaccurate - not always hitting the paper at 100m and the grouping could be described as "shotgun pattern" at best.

It looks like a rebarrel is in order, which is where I find myself with an additional quandary. On one hand, there's this WWII-dated SMLE Mk III which is in decent shape besides the barrel and I'm loathe to compromise its historic value by replacing the barrel with a brand-new one. On the other hand, if I find a contemporary barrel, there's no guarantee there isn't something wrong with it too - and the rifle's historic value is also compromised because it's starting to become a "bitser" gun at that point (the bolt doesn't match the action as it is, but that's not uncommon.)

I'm leaning towards getting a new barrel, since that's the best way to keep the old-timer in action (and accurately), but if anyone's got any suggestions or advice on how to proceed from here, I'd love to hear them.

[Peter Laidler]

Pssssssst, Colonel. Come a bit closer and listen to a Captain about how the Armourers shop worked regarding the words historic and bitzer. What do you think the real Armourers in the REAL world did when a rifle or a Bren had a shot out barrel. Do yoy think we worried our asses off worrying about whether the part-worn barrel on the bench might offend a turkey later in its life or whether the gunner might come back and say that he didn't like the fact that the barrel had another barred out serial number............... Nope........... We got on with it, changed the barrel, range tested it, accuracy and zeroed and sent it out

Replacement barrel. If it's gotta be done, be done with it. And while you're there, just get the bolt fitted and set-up correctly. CHS it and bloody re-number it so that the bloody thing DOES match!

[CINDERS]

I would have thought a quick trip to the gunshop and a bore scope may have been cheaper and less time consuming, I agree to a point with the dilemma but unless it is of significant history like one "Billy Sing used on Gallipoli" then swap the barrel out and go out and enjoy yourself.
That's why you have shooters and the others are just safe queens I have a couple of No4's for range work and a Mk III for a change but now you know the truth time to march on and get the barrel changed and a good general tune up if the draws are a bit tired or even a good soaking with BLO whilst you have the chance to do it.

[stevebc]

I'll echo Patrick Chadwicks comment #1: I have a Lithgow whose muzzle/crown was worn and the lands/groooves just petered out in the last 1/4 inch. You could see where they had been, barely, but it printed like a shotgun at 100 yds. I bought a 45 degree piloted reamer (the only angle I could find) and with a few gentle turns (the steel is like hard cheese as far as the reamer was concerned) it came up looking like this:



It looks odd, I'll admit, but it now shoots very well indeed.

[Bruce_in_Oz]

It may look odd, but it works.

Another thing, (or two), to remember about boat-tails:

1. the formation of the boat-tail on the bullet requites a separate operation in the bullet-forming process; thus, there is an additional potential source of "error" in the alignment of aerodynamic and mass centre-lines. This is why many bench-rest shooters only use flat-based bullets at the shorter ranges (up to 400yds) and change to boat-tails for longer distances.

2. The boat-tail prevents any effective "bumping-up" at launch; in a typical Lee-Enfield barrel (0.311" bullet, 0.303"-ish bore, 0.319" groove) that means "bleed" of erosive gas around the base of the bullet. NOT a good thing for throats / leades.

3. The effective parallel bearing surface of the bullet is significantly reduced. ANY misalignment of the bullet in the (generous) bore/groove WILL mean that the bullet may be precessing as it travels up the tube and this can only get worse as it enters the atmosphere. This precession SHOULD settle down somewhat as the atmosphere bears on the bullet, somewhere down-range.

4. A boat-tail allows a longer transition (relatively speaking) of bullet from muzzle. During the time that the bullet "tail" is clearing the muzzle, a cone of gas erupts around the base and races forward around the projectile. If the muzzle is less than "perfect", this high-pressure corona will not exit evenly and thus will act unevenly on the base of the projectile; more "wobbles".

4. Boat-tails are VERY good at reducing disturbances to the trajectory and velocity once in the trans-sonic region. Out to 800yds: not so much. This is why Mk8 was invented. It is essentially machine-gun ammo, designed to improve the "reach" of goodies like the mighty Vickers. Note: changing a barrel on a Vickers (or Bren) is a bit easier than doing a barrel swap on a Lee-Enfield rifle.

5. If your pet Lee-Enfield is relaxing in style after decades of eating Mk7, cordite fuelled ammo, it will probably have some throat erosion. Stick with Mk7 z (in the unlikely event you can find any) or reload with flat-based bullets of .312" diameter.

That said, I use boat-tails in my Schmidt-Rubins; the rifles were built for them, especially the K-31 series. The 1911 rifles and carbines are throated to handle the earlier "torpedo", a bullet not unlike the Mk 6 .303, but will handle the GP-11 ammo, or reload "equivalent", quite nicely. Never being used with Cordite probably helps, too.

[Colonel Enfield]

There's been some great advice here and I shall have to look into it further. At least with a nominally stuffed barrel, if I have the muzzle reamed and it doesn't work, oh well, nothing lost since the barrel's had it anyway.

To be honest, I was initially annoyed by the whole thing, but I might look on it as a project now - maybe find a suitable gunsmith and give it something approaching a 21st century FTR to put it back in accurate action (after I price replacement barrels... )

[Thunderbox]

What does the bore actually look like?

Is it shiny or frosted? Does the rifling have any discernible edges, or is it rounded or flat?

To be honest, the only SMLE I've come across that consistently keyholed and/or missed the zero target had a very obvious problem with the bore (the owner hadn't noticed that it was a .303" smoothbore.....). Lots of SMLEs with badly rusted or very worn bores group badly or throw and occasional keyhole, but then again i find that nearly all of them can be made to shoot after a fashion - usually by using cordite ammo. I've even posted here before about a rifle in relic condition that shot completely normally, despite only having a few inches of rifling near the muzzle - the rest having corroded away completely.

It may be that your rifle has some other issue (bedding, missing parts, etc) or simply does not respond well to handloads. With all respect to whoever is doing the handloading, you cannot make an accurate diagnosis unless you try some surplus or commercial ammo as a benchmark.

[Surpmil]

Before I did anything else I would do the same test with .303" Mk7 ball. I don't see how/where the red circle indicates a non round bore!!!!!! Where? If it's not round, then by definition it's not round around the whole circumference...... Or am I missing something?

Cordwear WAS a known problem at the muzzles of rifles and always asked about at trade test times where you'd be asked to identify barrel faults. But I don't think I ever saw one in real life!

But with BSO's, we ALWAYS try a different batch of stock ammo before anything else

I always wondered about that.