doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Blown Baker

Here's the scoop on the barrel. Few are as knowledgeable as this guy on barrels, especially damascus. Bores are perfect in condition and dimensionally. .725 BD top to bottom, both barrels. Chokes F/F with full choke length. Here's the bad news. Eightbore you called it... Chambers and forcing cones have been lengthened. Chambers to 2 7/8" and forcing cone the length of the dark area. The tooling marks start about 1 1/4" from the breech and end at the end of the forcing cone. It appears as not to be a reamer job, maybe a hone on a drill as it is uneven and gouged. That is the cause of the tooling marks. The dark area is the crudely lengthened forcing cone. NOT PITTED, just discolored,tarnished and easily polished out. No indication of pitting in or outside the chamber area. Right barrel discoloration is the worst, but slightly shown in left barrel. No indication that the discolored area had anything to do with the barrel coming apart. He measured the far edge of the burst and it recorded .090" and the back as I indicated was .112". He felt ballistic pressure for what ever reason was the cause of the burst. He felt the barrel integrity was solid and no indication it would give way under normal shooting even with the chamber/forcing cone hack job. His wall thickness gauge is broke. Randy

I have reviewed the pictures of the barrel failure and have made the following observations.
1/If the shell pictured was a standard Remington 12 G. Trap load the breech pressure to be expected would be in the order of 10,000 P.S.I. This is much too high for a damascus barrel. [As others have pointed out;"LOW BRASS DOSE NOT EQUAL LOW BREECH PRESSURE".]
2/Looking at the deformation of the shell, It is my opinion that the actual pressure was far in excess of 10,000 p.s.i[ie; See Burrard, The Modern Shotgun, Vol,3 page 408, for pictures a shell damaged due to excessive pressure.]
3/ The rupture/tearing of the shell case and the damaged wads seen in the pic;suggests that there was a possibility that fragments of a shell case or wad from the previous shot could have been lodged in the barrel immediately ahead of the forcing cone. If this was the case, a wave pressure would have been generated this would have the effect of increasing pressure at point of failure by more than 200%.
4/The barrel as seen in pics; 2&3 indicates that the welding of the barrel coil[breech end] was unsatisfactory.The weld clearly lacks penetration.This defect will act a stress raiser when the barrel is under pressure.This is most likely the primary point of the barrel failure.
5/Other pictures show what appear to be serious metal defects, namely ,lamination and a crystaline structure, both of which would have a negative impact on the ultimate strength of the barrel.
6/ In pic;7 We can see evidence of pitting, but more importantly in pics; 14 & 21 it appears as though rust has developed in the faulty barrel weld and also under the barrel rib.The fragment of the barrel that was recovered is also very rusty. However this could have occured after the failure.

SUMMARY
The probable cause of failure was an incorrectly loaded shell that resulted in excessive breech pressure. A partial obstruction in the barrel due to fragments of a shell case or wad being lodged in the barrel immediately ahead of the forcing cone is a distinct possibility. This being the case, wave pressure build up would occur.The high breech pressure,combined with the defects in welding, poor metal chemistry, lamination, pitting and rust resulted in the catastrophic failure seen in the pictures.

It never ceases to amaze me how many people simply cannot read & then grasp what they have read. James said;

Now that is quite obviously not speaking of the base wad from the hull, but the base of the CB wad which is missing in the pic.

The specifications of the "Reload" used have been stated several times & pressure was supposed to be on the order of 5500-5800 psi.
No question in my mind it was Excess Pressure, & had nothing to do with the fact it was a damascus bbl.
Quite possibly the idea of faulty ignition wth the shot charge moving & then becoming an obstruction to the powder gases catching up has a lot of validity to it. While low pressure is good, it just may be than "Super Low" pressures can under certain situations be "Super Bad". Many years ago I adopted the policy of loading for older guns, whether damascus, twist or early steel of staying with loads between 7K & 8.5K & so far have had no reason to believe these pressures to be detrimental to the guns used.

About 20 years ago a friend bought a box of Charles Dalley marked 20 Gauge field loads to shoot trap with in his Ithaca 37. The first shot locked up the slide. I don't recall how he got the shell out of it. He returned the shells to the dealer for his money back. I still have the shell. The primer is very flat. The rim flowed into the exstractor cut and all around its circumfrance in the rim cut into the barrel. Gas marks show on the skives where the plastic comes out of the brass. This was a factory shell and definately was making more than proof pressure. The gun was still useable. I don't know if there was any dimensional damage to the lock up. Hats off to Ithaca for such a strong light gun. I shot an apparent overload out of an Ithaca SKB Mod 200E Skeet gun. I remember shooting at high 2 with a terrific recoil. The gun opened up. I thought it came appart in my hands. The stock cracked at the head. Later on the fore end lug got loose and I sent it back to SKB in Japan to have it resoldered. I load my 12 Ga shells on a PW press that I have owned since 1984. That is the only shell that I ever had an overload problem with. I don't know how or what caused it. I cannot believe it was the press. I've loaded I don't know how many 10's of thousands of rounds on it and love it. The odd thing is that the empty shell(old AA) was not deformed in any way. Maybe we blame ourselves for these things. Most often it is our fault. But can the factory be the blame sometimes? Is it possible that Joe the primer maker can make a mistake? How about 2 primer pellets in one battery cup. I don't know if it's possible but would think that could raise some hell in a shot shell. I know that more powder or shot in a shot shell gets noticable fast when it won't crimp right or close at all. What would a live primer do if loaded into a shotshell? It does not matter what loader you have. Sometimes I have live primers fall off my loading table. They mostly land on the floor. But I keep my empty shells in target boxes near the loader. If one were to fall into one of my empties that was about to get loaded maybe that is how one could get into a loaded shell. Maybe that is what happened to my 200E. I guess a little house keeping is in order.

I'd have to agree with what Roy said...

How much did a Baker SxS sell for when it was new ?

I'm betting the price reflects the quality of the barrels.

50 + years of experience in investigating problems related to strength of materials and structural failures has taught me that by reviewing evidence, based on the facts as first presented, almost always results in a satisfactory identification of the root causes of a failure. This why I chose not to be influenced by the earlier posts on this subject.

Dear eightbore

You are right I know nothing about PW reloaders.

What I do know is that all of the guns that I speak of where shooting shells, that by the owners admission, were loaded on a PW.

Now as four in 20 years and however many millions of rounds were fired is a number that is statistically insignificant, it still is 100% for PW reloaded shells.

Also none of these guns were old and all were made for SAMMI spec shells.

Thank-you Miller. As usual, you speak sense.

This may not be the result of an incorrectly loaded shell at all, rather a correctly loaded shell that performed incorrectly.

Modern primers are very reliable, but I've found them not to be 100% reliable. I've found several WW209's in the primer tray without priming compound, and have had several others over the years that did not fire. One wonders if sometimes a shortage of priming compound or perhaps a faulty anvil could lead to incomplete or two stage ignition of a shell with catastrophic results.

This sort of thing would leave no forensic evidence.

Eightbore, at 2:00 AM the bridge is almost always empty. At least it was for me. Your rant was a good one and I for one loved it. You, in no way offended me and you know it I hope.

Warning to all board members do not insult a mans dog's looks or his PW. I have done both and lived to regret it. I have MECs for the boys to use and a Spolar now myself. This is just an updated PW in many ways. PWs are fine machines. Sorry if I got under your skin Eightbore.

PWs are fine machines, if the UPS man knows where you live so he can deliver parts to keep it running. Oops, I did it again. Sorry. A PW and for that matter a Spolar are a fine machines that do not tolerate tinkers and home educated repairs. Unlike a MEC, which any idiot could take apart and put back together, with a reasonable hope of getting it to work again, PWs have just a few more moving parts which most reloaders have no hope to get back correctly in place and timing. From what has been posted here this PW seems to be operated by someone who knows what to do so that is not a problem.

Eightbore, I have loaded a 100-150K on PWs before I replaced them so I am not a virgin in PWs. Certainly you may have loaded ten times as much and I deffer to your expertise in this area. My remark about the primers on the MEC vs. PW loaders deals with the MEC machine tendency to have the primer hang up and then fall off the primer drop or have one fly off it if the spring return suddenly flies back. I understand how a primer might drop off the PW and by some weird fate land in the powder. I just think that it is ten times more likely with a MEC than a PW.

I would be willing to pay real money to have a "live primer in the powder" load tested to see how much it increases the pressure. Maybe someone can get Hodgdon to run a test of have Mr. Bell run a test. Count me in for a hundred bucks.

Once again I am sorry if I made you just a tad touchy about those PWs. By the way it is off the right side of the bridge on the Annapolis side of the channel if you are looking for parts for your machine. I did keep the hydraulic setup off that machine and used it on my Spolar. Had to change one small part and it works just like a PW.

I measured 11 sets of damascus barrels last night. I measured them 1" from the end of the barrel. The thinnest measured .178, the thickest measured .301. Most were around .28. They included Lefever, Ithaca, Aubrey, Remington and some unknown barrels sets I have. They were laminate / twist and damascus up to 3 iron. I do not have a set of Baker tubes to measure.

I am not saying the wall thickness caused the rupture, nor that it ruptured because it was damascus. In this case, the damascus may have prevented a more serious injury. A split fluid barrel at that point would run down the barrel for a ways, almost certainly causing injury.

Pete