doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel Burst- Beretta 682?

Bill;
In the model making shop I worked in a fellow machinist had a very large piece of steel in a lathe making a sting which would be used to mount a model in the wind tunnel. He had the large end of it chucked in the lathe with the small end in a steady rest & was tracing a taper in the mid section. He was running a water based soluble oil coolant at the tool when all of a sudden coolant began running out the bore of the part. Seems the steel had a large interior hole in it. Steel had been procured from a source approved by the customer & supposedly Certified. The steel company of course replaced the steel, but we lost a bunch of man hours in the process.

Of course when smaller pieces of steel are drawn or rolled is when "Seams" are formed rather than a hole as in this case. The worst of these will be caught in machining or the proof testing but others are hidden & will pass proof & may never present a problem, depending upon their, size, location etc & the thickness of the wall where they occur.

As stated though this burst could have been from either an internal seam or from a thin spot being created in the striking next to the rib. In either case it my well have never burst had not the obstruction bulged the metal beyond its tensile strength. Had not the weak area been there the obstruction "May Not" have burst the barrel but only bulged it.

It would of course take a hands on inspection by a knowledgable person to make an absolute analysis of the cause. Much reasonable thought & possibilities have been discussed here. Of course from Wonko the "Insane we have heard only Noise & Static.

LOL Miller!! Great story. The same thing happened to us. Lost a bunch of man hours and the company replaced the material. The only time I have seen holes like you described were in castings. I hated castings.

Been a lot of years since I have heard reference to a tracer and machinist in the same paragraph.

It seems that there are high end makers with vacuum remelted barrels. Are these barrels "better" or is the process like milking a goat in a tuxedo?

jlb

Bosis & Fabbri are two. Bosis and Flodman also offer titanium barrels.
Tensile strength is much higher, which allows the use of thinner/lighter barrels, but that may negatively influence balance and swing dynamics.
Plain 'ol 4140 barrels will last a lifetime of even competitive shooting.

jlb Best work isn't for everyone. Nor need it be.

Small batch, vacuum arc melted, proprietary alloys, with exacting post melt handling, stress relief, quality confirmation, and state of the art machining, are but the first steps taken to produce Fabbri barrels.

Their incredible strength allows for greater latitude in building to specification.

Would an everyman benefit from them? Depends on how you decide to measure your benefit. If you are worried about them blowing off your hand, they are good enough.

I used the search function to re-read an eerily similar thread from 10 years ago.
Wonko was/is right.
Read Burrard if you can.

I hope wonko isn't right, otherwise wouldn't you consider this a bit dramatic to be wrong? I'm gonna write that down, best gun, no blown up hand worries.

I think most of the stuff you mentioned above has to do with proper heat treatment, and maybe a bit of quality control. What's the vacuum melt for?

Vacuum remelting is a purification process. Much like re-crystallization in chemistry, but in molten metals.

Some impurities gasify at less than atmospheric pressures when heated. So, you can get crap out of the melt that you can't get out at atmospheric.
C, Mn, S, other stuff.
It's considered essential for working with Ti.

It's for ultra purity.

Then of course, there's the solidification process (cooling), micro crystalline control is exerted over the melt.

Wonko was right in his comment that ruptured barrel threads die quietly, with no definitive conclusions.
People studied ruptured barrels extensively during the transition time from laminate to fluid, mandrel welded to drawn and bored barrel making. 2-piper cited Burrard 10 years ago, who did much of the studying.

In these threads about angels on pin heads, ultimately decisions are made by people saying, "It's good enough."

When a gun maker is 500 years old, and has been a leader in advanced manfacturing techniques for milions of firearms, people are looking at the wrong end of the horse for the "why".

Thank you CZ for the explanation of the part I snipped out. I personally prefered it to the previous.

There seems to be some conclusion that impurities in the metal, steel in this case, caused the failure. Some of those double vacuum melted steel alloys are incredible things, but more often than not, they seem to be high carbon hardenable steels. I don't know if it makes much sense to imply that regular fools settle for good enough.

Only for curiosity, if a ring bulge shows up, it's possible that the manufacturer was unlucky enough to release a barrel tube that had near perfectly distributed circumferential inclusion defects? I'm not thinking that could be concluded, just that maybe it's a viable scenario? Maybe the maker is at fault? Wouldn't a blow up violate the owners manual and stamped warnings about safe operation? Small as it may be, I think there's some learning to be had.

I've been a party to two barrel ruptures in modern shotguns. In both cases, it was factory new ammunition used in near new single barreled shotguns.

As was the case in the 10 year old thread, the firearm manufacturers denied the claims, saying it was caused by over pressured or obstructed barrels. The ammunition manufacturers made the gun owners whole, without a peep or squeak, within days of contact.

As far as "good enough", every manufactured product has specifications that are "good enough". They meet or exceed the specifications, and move along.
Another way to say it is, "Hey boss, when do I quit polishing this?"

And, lest one forgets dynamic cycling stresses and multiple QC checks and proof loads per CIP, inclusions manifest at low cycling rates, not 35 years later.

Joust a couple months ago, a friend showed me a hydraulic manifold from a Cat tractor or excavator or such. This was a machined cube block of aluminum about 8" on a side with holes drilled in it to form the manifold. It had a leak no one could find. After my friend got it, he pressure checked it over and over and finally located the leak along a perfectly straight line. It turned out to be what is called a "cold lap". It was formed during the process when the plate was created from ingot. It was very tight and invisible to the naked eye.