How to bulge a barrel

[Little Oak]

A lifetime ago, when I shot competitive 25 yd .22, there was an elderly gent who shot with us and had an absolutely pristine BSA Martini International that had a beautifully blued barrel that must of been at least 1" diameter. He shot quite well but one time, after the first card, he didn't look at all happy - we soon all found out why!
About 1 1/2" - 2" back from the muzzle was a perfect, large duck egg size bulge.
He confided that he cleaned the rifle after each shooting session, left the bore oily and dried it before he left the house to shoot next time. This time he had forgotten to dry the bore and this was the result.
Those, including myself, who saw it were extremely impressed that a .22 LR had enough oomph to hydraulically bulge such a big tube to such a degree.
I believe the event upset him so much, that the gent sadly gave up shooting after that.

[ulav8r]

One of my instructors at CST had a 22 autoloader with 4 bulges in the barrel. Don't remember the make and model. He had gotten it from the owner that had put them in, but I don't remember if he knew the details. I think two were within 6 inches of the muzzle, the two others were spaced about 6 inches apart near the middle of the barrel. It was a 24 inch barrel and he said it was still very accurate for an autoloader. The bulges were very noticeable from the outside.

[Geezer in NH]

IMHO a .920 barrel will not show a ring on the out side. It will in the bore with optics or a good eye.

I sold a few thousand barrels on the internet 10 years ago in my company name, and many with no name to the SPG all made in NH. Blemishes were not the bores they were fantastic!!! outside measurement maybe .002 shy and fit the same stocks on the market.

However the very few with rings visible in the bore still shot excellent. Who knows why? When I say ringed there were 6-7 I can really remember, they were mostly shot with some kind of no powder type rounds that then got shot with a standard 22lr.

[Earlwb]

To tell the truth, I would have never thought it was possible to ring a .22 rimfire rifle barrel. Usually the barrels are pretty heavy duty to start with and the rim fire cartridge isn't exactly a high pressure item either. But you live and learn. Amazing stuff.

[Texas by God]

I had a 90 Win pump with 3 bulges. If you closed your eyes and pulled the trigger you had a better chance to hit. No,I'm serious.
Best, Thomas.

[EDG]

When I was a teen ager a guy brought me a 22 to work on that he could not hit anything with.

It was a Remington 510 single shot that had 3 bulges in the last 4 inches. After cutting off the barrel it shot fine.

[TCLouis]

I have a fine little Falling Block (HW 28) that has a loose section about 2-3 inches long about mid barrel.
Explain that other than manufacturing flaw.
It shoots pretty well so I have never been able to talk myself into a reline job.
Barrel is so unique with an integrated rear sight mount system that works as a scope dovetail (though I doubt that was ever the original intent) so a reline is the only possibility.

[Ballistics in Scotland]

Experimental evidence now proves that localised ring bulges are caused by a gas pressure wave, when the bullet hits an obstruction solid enough to make it decelerate.

Paul Vieille, the inventor of smokeless rifle powder, ignited powder at one end of a long, sealed cylinder. When the powder was evenly distributed along its length, no unexpected pressures were found. But when it was located at the ignition point, local pressure several times as high was recorded at the far end, where the gases came to a stop. He even mounted the cylinder on a sensititive pendulum which could measure the movement of the weight of gases and part-burned powder, and he found that they would bounce, being elastic, several times between the two ends of the cylinder before it came to rest.

Two fallacies about ring bulges have been exploded. It was often held that the metal of the bullet or obstruction expanded on impact. But bulges have been achieved experimentally with hard metal bullet and obstruction, which were picked up unexpanded. Another theory was that it was the confined and compressed gases between bullet and obstruction that did it. But exactly the same can be achieved with an obstruction of heavy metal tubing, which can't confine gases, but can decelerate the bullet. It is a small body of very highly compressed gases that does the damage.

Shotguns, moreover, are particularly prone to ring bulging, often producing the distinctive tulip-shaped barrel amputation which product liability lawyers love. Indeed it is almost unknown for pure overpressure to burst an unimpaired barrel more than three or four inches ahead of the chamber. This picture is the barrel of a single barrel shotgun I sacrificed, elderly and unloved but of modern steel and considerably thicker, for recoil reduction, than you are likely to find in a double. My obstruction was a couple of steel nuts wrapped in tissue. They and most of the shot ended up leaving the muzzle.



It shows the rare but well documented double ring bulge, which is significant because it proves that something bounced to and from the inside of the cartridge case, and it wasn't metal. As usual the first bulge is a little ahead of the site of the obstruction, since it moved while the pressure wave was catching up, and the second is further along, where it moved as the gases went two and fro. That was about two inches of movement for one, and a total of about thirty to and fro for the other. Energy is proportional to mass and the square of velocity, showing that the destructive power of the gases can be extremely high.

The most likely obstruction is a bullet, caused by a defective round or some member of the intellectual classes removing powder to dispose of indoor rats with less noise or damage. This was easier in the early days of the .22 rimfire, when the bullet was uncrimped. But it could indeed be water. A .22, with its small calibre and greased bullet, can retain it by capillary action until the breech is opened. Interestingly General Hatcher obtained reasonable short-range accuracy shooting a .22 entirely underwater, with no mention of damage. As the barrel was entirely filled, the bullet experienced less acceleration, not sudden deceleration. The range was slightly more than he thought would protect a swimmer from a .30-06 bullet from above the surface.

[Ballistics in Scotland]

[QUOTE=TCLouis;4078942]I have a fine little Falling Block (HW 28) that has a loose section about 2-3 inches long about mid barrel.
Explain that other than manufacturing flaw.
QUOTE]

It's none too easily explained by a manufacturing flaw either. I think the most likely explanation is that someone with a bore obstruction didn't realise it, and fired several shots that way, with the effect moving little each time.

[54bore]

Called ringing the barrel, i have not done it but have been told if you short start a patched round ball (inch or so in the barrel) forget to seat it to the powder, and fire it, i have been told that will/can 'ring' the barrel up by the Patched ball at the muzzle end. A good friend of mine ran up a steep bank trying to get a shot at a deer, when he seen the buck and pulled the trigger his barrel at the muzzle end split, resembling a Y he claims nothing got in the barrel? I call bs, something jabbed in that muzzle on his trip up that steep bank, he didn't know it, pulled the trigger and she came undone!

Anytime i hear of a bulged, ringed barrel, I immediately say obstruction of some sort

[Ballistics in Scotland]

Called ringing the barrel, i have not done it but have been told if you short start a patched round ball (inch or so in the barrel) forget to seat it to the powder, and fire it, i have been told that will/can 'ring' the barrel up by the Patched ball at the muzzle end. A good friend of mine ran up a steep bank trying to get a shot at a deer, when he seen the buck and pulled the trigger his barrel at the muzzle end split, resembling a Y he claims nothing got in the barrel? I call bs, something jabbed in that muzzle on his trip up that steep bank, he didn't know it, pulled the trigger and she came undone!

Anytime i hear of a bulged, ringed barrel, I immediately say obstruction of some sort

That is even more likely to be true if it happened with a muzzle-loader than a breech-loader. Terminal pressure is likely to be lower, and the barrel walls near the breech are likely to be thinner relative to those at the muzzle. I think you would see the remains of a bulge near the apex of that Y, made before the rest of the barrel came unzipped.

I think an obstruction being hit by the bullet, unless it was a really immovable one, would only create a ring bulge if it was rather further than an inch into the muzzle. Remember the gases do take a little time llto build up behind the bullet, so the position of the bulge is a little further along than the rear of the obstruction. If the obstruction has exited, no damage is done. That is why we can have shotguns with a choke. Damage caused to the choke by the unwise use of ball, or steel shot in an old barrel of soft steel, will be mechanical, caused by metal to metal contact.

[NavyVet1959]

Well, I did some measurements on the barrel today. It's not a *complete* bull barrel in that there is a very slight taper along its length. It's 0.750" at the breech (after the reduced diameter portion that slides into the receiver block). It's 0.624" at the muzzle end of the barrel. The bulged portion is 0.648". On the breech side of the bulge it is 0.640" and on the muzzle side it is 0.636". So, averaging it out and interpolating, I would hazard to guess that it might have originally been 0.638" where the bulge currently is and thus 0.010" of a bulge.

[Hardcast416taylor]

I have actually seen match shooters leave a patch in the bore near the muzzle to discourage insects from making nests in the barrel at their home. They then remove the patch at the match. I still vote for `mud daubers` though.Robert

[Ballistics in Scotland]

I've seen a little felt cylinder for use on a Dremel tool used. They have a little hole for a screw mandrel, which can be used to screw on a piece of card to stick up into the sight line and remind you. But I think it would take an oil-soaked patch extending well into the barrel to ring it. Remember, it takes deceleration of the bullet to do that.

Despite lower amounts of energy, a .22 rimfire is in one way more susceptible than most to ringing. With traditional loads there is little or no acceleration beyond the twelve-inch level, so deceleration is more easily done.