Gun with a 180 bent barrel -- will it explode or will it fire Tom and Jerry way? - Page 1
Forum section: electronics / general

author: blueskull
author_rank: Unknown
timestamp: July 15, 2020, 04:10:09 pm
content: I must admit I was expecting the barrel to explode or at least rupture. I would never dream this to actually work.

author: Domagoj T
author_rank: Frequent Contributor
timestamp: July 15, 2020, 05:05:51 pm
content: https://en.wikipedia.org/wiki/Krummlauf

author: Syntax Error
author_rank: Frequent Contributor
timestamp: July 15, 2020, 05:12:47 pm
content: Okay, so the inventor shoots himself in the headGENIUS

author: Cerebus
author_rank: Super Contributor
timestamp: July 15, 2020, 05:35:30 pm
content: Quote from: blueskull on July 15, 2020, 04:10:09 pmThought of as a machining process, firing a bullet is a swaging operation. That rifle looks to be chambered in 5.56 mm - the mean gas pressure behind the projectile is around 350 MPa, peak is even higher. The yield strength of mild steel is around 210 MPa, the slug in question would be even lower. It's no surprise that a pressure that high can persuade the bullet to deform to squeeze around corners to conform to the barrel.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: July 16, 2020, 03:03:46 am
content: When I was a young lad, I was something of a gun nut. My parents, who experienced WWII Germany during their pre-teen years, didn't want any firearms in the house. They were dismayed at my interest and tried to discourage me. They did however relent and allow me to go hunting with my friends and also join a gun club. At the gun club I received the required safety course which did emphasize keeping mud out of the muzzle and checking for barrel obstruction, because "your barrel could blow up".At the time I also wondered if barrels would split open like a cartoon depiction. My father said he witnessed FLAK cannons split open because of bad ammunition, perhaps sabotaged ammo as it was made by slave labour. Towards the end of the war boys were enlisted as FLAK helfer (helpers). But those cannon rounds had integral explosive so it still didn't resolve the question for small arms inert lead jacketed bullets hitting a blockage.At the same time I was in the gun club I would also visit a gun shop/smith and basically be a pest slobbering over rifles I could not legally buy on my own. The owner tolerated me as he probably figured I would be a good future customer. One day I noticed a rifle in his "to be worked on pile". From the muzzle end to 20 cm back a section of barrel had a big splinter missing and a soft point bullet lodged, with the tip slightly expanded. The gunsmith did confirm it was mud although whatever had caused it was washed away. So I had my answer.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: July 16, 2020, 05:58:45 am
content: All things seem to be possible. I have seen splayed open barrel ends. And seen a barrel split almost like a chinese lantern. Both ends intact but the middle bulged and split. But have also seen mud plugged barrels fired with little or no ill effect. But the latter outcome is kind of like winning at Russian Roulette. Not something normal people would try or count on.My dad was an amateur gunsmith, and proof fired the products of his work using a heavy load with the gun strapped down and fired remotely in a sand pit. Hearing chunks of metal whizzing through the air and seeing the aftermath of a failure makes a really strong point of not mistreating these things in any way that you can avoid.

author: Cyberdragon
author_rank: Super Contributor
timestamp: July 16, 2020, 05:57:43 pm
content: Mythbusters did a whole segment on this once.

author: GlennSprigg
author_rank: Super Contributor
timestamp: July 17, 2020, 10:55:49 am
content: I had aLithgow .303rifle a long time ago when I was 19/20. I 'experimented' with removing more and morepowder from the cartridges, until it would just come out. It seems the slugs are normally quite tight in therifled barrel, and one stuck half way. I forgot about it, and ages later I fired afull cartridgeinto it!!Now they were 'really' stuck!! At the time, I thought it miss-fired, but pulling the bolt back released the gaspressure!! And nope, the barrel didn't explode...I pulled it apart, and melted the lead out of the barrelon the gas stove. It was fine after that!!(I was young & ignorant then. Not now...)P.S.Out of interest to people, many years later, my (educated) older brother was President of the NorthernTerritory Gun Club. (Post Army). He demonstrated to me a'sawn-off' shotgun, using specialized home loadedcartridges, that was actually 'Tuned' lengthwise, (the pellets somehow 'resonate' down the barrel), so that itcould put all pellets in a 2" diameter circle, at about 40-50 feet!! (No scattering?). Seeing was believing!!P.P.S.He also showed me how most 'movies' were fake, showing 'Silencers' onsnub-nosedPistols. Due tothe fact that the 'powder' is generally still burning after the end of the silencer, so it's still noisy. You need along barrel pistol, and fast burning lower power cartridges... Again, seeing & hearing was believing.MyRuger .22 semihad telescopic sights, and a silencer for quiet rabbiting. Nothing 'sinister'. I remember beingamazed how there wasNOother sound heard, except the clicks of the trigger!! All history now. Not needed.

author: KL27x
author_rank: Super Contributor
timestamp: July 18, 2020, 08:27:47 pm
content: The sawn off shotgun trick? I assume he installed a choke. The choke is what makes the spread tighter; the length of the barrel doesn't matter, unless you allow it to take up a significant percentage of the distance to the target. When you saw the end off a shotgun, you are removing the choke in the muzzle end; that's why the spread increases. The choke is basically a slight reduction in the bore and it has an effect something like a focusing lens.The silencer can work on any length barrel. It can't work (very well) on a revolver because there's a gap between the cylinder and the forcing cone of the barrel. The gases shooting out of there will be enough to wake the dead. This is also the reason you can't shoot lead reloads in a revolver or a blowback pistol without making a lot of smoke. Lead bullets require lube, and the hot lube shooting out the gap produces the smoke. In a locked breech firearm, the bits that make the smoke can get fully combusted.There is a revolver called the Nagant (early 1900's or maybe late 1800's?) with a cylinder that moves forward and back. The brass case is longer than the cylinder but crimped over. When fired, the case mouth flares open to seal the cylinder gap. It was military issue in its day. Britian? US? Don't remember. But it was sometimes used with a silencer.The gases shooting out the cylinder gap can cause damage to the shooter, in extreme cases. You have to be careful how you hold a S&W 500 revolver, or you can end up in the ER with a nasty finger wound.Your brother sounds like a colorful chap, spreading colorful theories.

author: james_s
author_rank: Super Contributor
timestamp: July 18, 2020, 10:28:46 pm
content: Barrels can certainly split open, especially things like shotguns and the previously mentioned flak gun that have large diameter barrels relative to the wall thickness. It's hardly surprising when you think about the fact that a bomb is an explosive substance inside a metal casing and in the case of a propellant like gunpowder much of the force of the explosion is caused by the rupture of the housing.A bend in a barrel up to about 15 degrees is probably not going to have too much of an effect beyond the obvious reduction in accuracy however you'd have to be really careful to ensure that the inside diameter remains round, it will tend to flatten a bit as the bend angle increases.

author: GlennSprigg
author_rank: Super Contributor
timestamp: July 19, 2020, 10:47:48 am
content: Quote from: KL27x on July 18, 2020, 08:27:47 pmThanks for your info. That's interesting, thank you. However, regarding your last line, it wasn't 'theory'!!As I first explained, that "Seeing, (and hearing), was believing", as hedemonstratedit all on the Range.It was maybe 20-25 years ago, so I forget if he mentioned a 'choke' in the shotgun barrel.Maybe so? However,he had about 3 or 4 'sawn-offs', (amongst many other rifles/pistols). He explained, (and demonstrated), how thepellets can move in a 'wave' pattern down the barrel, and by 'tuning' the length precisely, just when the pelletswere at the point of converging again, (or the 'pressure' wave surrounding the pellets?), they would stay together.Evidently this also required precise home-assembled cartridges, for consistency.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: July 19, 2020, 11:14:54 am
content: The Lithgow factory now is a museum.