Browning Citori blew up!

[runfiverun]

wrong powder wouldn't do it.
I have loads for my 12 ga that use titegroup, and loads that use bulls-eye.
so even screwing up and putting 17.?grs of titegroup instead of 17.?grs of titewad wouldn't cause a gun to blow up.
now you could be using green-dot [at like 19grs] and pour in some titegroup or solo-1,000 and have too much powder.
would it disintegrate just the chamber area on a proof tested shotgun???
I doubt it.

[Ballistics in Scotland]

YouTube vid kinda shows a 20 won't choke a 12.. So powder has to almost be it

No, it shows that those shots didn't blow up that shotgun. It did produce bulging, and in that part of the bore, where the front of the chamber forms a local weakness, there isn't a big margin between that and rupture, which will be a very high-pressure rupture by shotgun standards. A pump-gun barrel, with its weight governed by recoil and with its locking surfaces closer to the bore axis, is likely to be stronger than a double.

[Soundguy]

Corrects, exactly what i said, a 20 won't choke a 12. You are too busy trying to explain something to me that I already agree with.

No, it shows that those shots didn't blow up that shotgun. It did produce bulging, and in that part of the bore, where the front of the chamber forms a local weakness, there isn't a big margin between that and rupture, which will be a very high-pressure rupture by shotgun standards. A pump-gun barrel, with its weight governed by recoil and with its locking surfaces closer to the bore axis, is likely to be stronger than a double.

[rking22]

Good friend was shooting sporting with a fellow who destroyed a Beretta 687 with a 12 20 combo. He called for the pair , got a click. Then opened the gun and said " wow , I forgot to load" , dropped a factory load in and blew it up. Sent him to the hospital for surgery on his left hand. OU barrels are not all that thick compared to pumpguns! Always empty the vest pockets between shoots, courses, ect. Just because one gun can take it without separating is not proof that all will ! I have seen the videos posted and shoot both 870s and Citoris, not going to test the concept,,, be carefully out there! I suspect the 12 20 did the deed to the Citori, glad he was not hurt.

[Ballistics in Scotland]

It looks like everything was projected at an upward angle, that would have passed overhead a fairly short distance away. It might have been much worse if it had been the lower barrel.

[RMc]

YouTube vid kinda shows a 20 won't choke a 12.. So powder has to almost be it

If you carefully watch the video in question, there are two things you should note:
- The barrel was bulged in the first 12/20 and further the 2nd time.
- A ramrod was run down the bore to insure the 20 gauge shell was in contact with the 12 round.

Then from post #50:

Had a gap existed between the lodged 20 gauge round and the chambered 12 gauge round, I suspect a catastrophic failure would have resulted. Such a gap is entirely possible in a 12/20 scenario with an overbore/back-bored barrel.


"12 and 20 gauge Citori shotguns feature Back-Bored Technology."

http://www.browning.com/products/fir...ns/citori.html

[Soundguy]

It doesn't appear that they seated the 20 to the 2 on the first shot, that ringed the bbl.

[RMc]

It doesn't appear that they seated the 20 to the 2 on the first shot, that ringed the bbl.

Consider the age of the Nobel 66 shotgun, barrels were not overbored and chamber throats were short for card/fiber wads. Now go back to the SAAMI shell and chamber drawing. Then compare the rim diameter of a 20 gauge to the standard 12 gauge bore that has not been ringed or bulged.

[Ballistics in Scotland]

It still seems quite a gamble, and at best likely to harm only the barrel. I think the main reason for the long forcing-cones now fashionable in shotguns is to reduce the abruptness of that weakening step at the front of the chamber. I don't much like them, and the user of slugs ought to like them less. They probably offer more chance for the 20 cartridge to enhance the danger by leaving that gap.

[Soundguy]

Consider the age of the Nobel 66 shotgun, barrels were not overbored and chamber throats were short for card/fiber wads. Now go back to the SAAMI shell and chamber drawing. Then compare the rim diameter of a 20 gauge to the standard 12 gauge bore that has not been ringed or bulged.

Consider the age of that shotgun and miles it has seen. That wasn't a new just proofed gun, it coil have had tons of shot thru it, stressing it for years. The fact that it didn't grenade is telling.

[RMc]

It still seems quite a gamble, and at best likely to harm only the barrel. I think the main reason for the long forcing-cones now fashionable in shotguns is to reduce the abruptness of that weakening step at the front of the chamber. I don't much like them, and the user of slugs ought to like them less. They probably offer more chance for the 20 cartridge to enhance the danger by leaving that gap.

Indeed a 12/20 situation is always a gamble! However, I do believe the combination of long forcing cones and overbore/backbore barrels exacerbate the danger involved

[Ballistics in Scotland]

I think it is dangerous in a double with any forcing-cone, but one of my ancient friends in early childhood told me a story that probably illustrates the importance of a gap.

A friend of his, on India's plains in the hot season, resolved to commit suicide with a Lee-Enfield or Lee-Metford. As a soldier he knew that people do occasionally survive rifle bullet in the brain (I know of Boer War and Spanish-American War survivals), so he adopted the standard military method, entirely unnecessary at muzzle blast range, of filling the barrel with water.

At the last moment he became reconciled with this world, which might conceivably get better. But such was his state of nerves that he accidentally fired, and blew off most of his ear. When he woke up in hospital he found the awful figure of the Regimental Sergeant-Major, product of a less fallible selection process than generals, seated by his bedside. In a panic he asked if he would be discharged from the army or even prosecuted, as suicide was then a crime. The sergeant-major told him with terrifying politeness (being a Scottish Highland regiment) that he had had a foolish accident which was its own punishment, so he would stay in the army and be put under stoppages of five pounds ten shillings, to pay for the rifle he had destroyed. The price at least checks out under research.

He was most annoyed, since there was no visible damage to the rifle, and that was the retail price, while Her Majesty bought in bulk. Even his eardrum wasn't burst. We all know a bullet thirty or forty grains heavier, with an unaltered charge, would be dangerous. But this one had stood a part-liquid projectile weight of 610gr. if it was the SMLE and MkVII cartridge, and more if it was one of the earlier long rifles, although even a lodged bullet would probably have produced a bore amputation. I think it was the total lack of an airspace that made the difference. It isn't, however, compression of that air or the obstruction or projectile, as some have suggested, that does the damage.

I have shown this picture before. It is my own experimentally induced double ring-bulge in a heavy single barrel 12ga, done with a tissue-wrapped steel nut. What happens, happens only if the projectile is materially decelerated. The gases catch up with it and build up to a localised wave of very high pressure. The double bulge is caused by that wave bouncing back to the breech face and forward again, by which time the projectile has moved on slightly. This shows that although light, the gases are moving enormously faster than the projectile, and energy equals MV².

[35 Whelen]

That barrel had to be plugged solid. Maybe a 20 ga shell dropped in first? There was nowhere for that charge to go, thus the shrapnel, and it wasn't just a wad. Wow

This is exactly what I thought when I saw the picture. Our gun club has a 12 ga. Remington 1100 displayed in which that very thing happened; the owner had been going back and forth shooting trap with his 12 ga. and skeet with his 20 ga.

It's really difficult to double charge a shotgun hull simply because doing so will usually make it all but impossible to crimp the shell.

35W

[Hamish]

"Harter66-"In shotguning the switch from a W209 to a Fed 209A will jump pressures 10,000psi , take a top load at 14,500 and it's 23,000 before you pull the trigger . Add a charge bar cut for 1oz of large steel shot and drop a charge of #8 or 9 lead and viola' now you 1 1/4-5/16 oz of shot sitting on 18 gr of Red Dot and a nice safe 12,000 LUP 1 oz trap loads is a 30k grenade right at the top of CIP proof loads maybe higher .""

You're saying that switching a 209 primer for a 209A primer with jump 10K psi? I don't know bout that....


Sent from my iPhone using Tapatalk

Harter66, I'm with Blood Trail on this one,

In perusing a couple of IMR load books I cannot find any loads that exceed 400 PSI difference between Winchester and Federal 209 primers, with the the Federals on the high side. Almost all were within 100 to 200 PSI.

I believe you are mistakenly substituting the fact that substituting WADS in a given load can drastically alter pressures.

I do not ever remember reading that the brisance of Federal shotgun primers was that much higher than Winchesters.

If you have any hard info concerning this I would be interested in reading it sir.

[Treeman]

Lab ballisticians have reported pressure increases as high as 3000 LUP from changing primers in shotshell loads. That is very significant but a far cry from 10KPSI.

[Harter66]

Examples can be found in the BPI Status of Steel circa 1995-98 editions .
Steel is more susceptible in shot shells to pressure variations . Also at that time there were Federal 209,209A and 209M in circulation .

[Hamish]

Examples can be found in the BPI Status of Steel circa 1995-98 editions .
Steel is more susceptible in shot shells to pressure variations . Also at that time there were Federal 209,209A and 209M in circulation .

Thanks, you may have saved my bacon. I've loaded lead and slugs for many years but am setting up for steel in 10 ga. i must admit to being oblivious to this particular issue with steel.

http://www.ballisticproducts.com/Sta...info/00MSTEEL/

[35remington]

I doubt very much a clay bird shooter had a 1 ounce steel shot bar mistakenly loaded with lead shot dispensing his load. Suggesting massive boosts in pressure from primer switching combined with inserting steel shot bars smack in the middle of a lead shot loading session make it appear whoever posits such weirdly impossible events has not thought about it much before posting. I remind that bars cut for 1 ounce of steel are based on volume, and the volume of such a load when lead shot is substituted is way, way more than a one ounce lead wad will accept and obtain a crimp. Shells simply buckle under such conditions when a crimp is attempted and it is very obvious something is wrong. The ratio is on the order of one ounce of steel being closer to an ounce and a half of lead....1 to 1.44. Sorry, won't fit.

The more improbable something sounds as a cause, the more improbable it actually is. How is it someone could load a single bad shell by overstuffing it with shot when the rest were OK? How can any semblance of a normal shell be produced when nearly fifty percent more shot than is intended is loaded?

[Harter66]

Well , I have a Pacific bushing that drops 18.0 gr of Red or Green Dot and 25.5 gr of 800x . I don't use that press much due to the composite bar and only having 1 shot bushing and 2 powder bushings .

If our loader used a fixed shot bar for say an 1oz of 2,3,4s steel that would drop nearly 1 1/4oz of 8-9 lead . Now add a paltry 2kpsi for the 209a VS a Rem #57 to 18.0 gr of Red Dot under an 1 1/4oz with a white RXP 12 . 25kpsi or a proof load .
It's actually not that hard to see .
Of course if you haven't used Texans , MECs or Pacific ( later Hornady) presses and worked loads tinkering with wad pressure, shot columns , powder changes , primer changes , soft ,chilled ,extra hard , copper plated , nickel plated lead , polished , polished annealed , copper ,zinc and graphited steel shot I wouldn't expect it to be seen as an easy mistake to make . In between I fitted the 5 MECs with adjustable charge bars with steel compatible inserts and bought lead inserts too.
RB and slugs , well ya got me there .

[Ola]

Double powder load! It is virtually impossible to blow a shotgun chamber with a "normal" obstruction - some has even survived the notorious 12 gauge on top of a 20 gauge mistake.

You are absolutely right. This is what a serious overload looks like.