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Joined: Feb 2009
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Sidelock
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Sidelock
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Sidelock
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Sidelock
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Sidelock
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Sidelock
Joined: May 2011
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Chuck - the engineering info you present is both spot on and quite correct. I would not, however, rely too much on it in the context we're talking about: a bulged barrel. The long and short of my reluctance (or objection) is that the information you're presenting is derived from carefully prepared laboratory tests run under controlled conditions. OTOH getting a gun to the stage of having a bulged barrel and now deciding whether to use it are not. They don't even rise to the level of a shadetree gunsmith tying a gun to a spare tire and firing it with a rope to see if it will blow up.
Other than illustrating ... something ... comparing a double with a bulged barrel to a Model 12 or other single-barrel is inapposite. There's a lot more going on with the double particularly, as noted above, under the ribs. Moreover, comparing this gun - with the bulge in the area of highest pressure 1/2 inch past the chamber - to any gun with a bulge near the muzzle - the low-pressure end - is likewise inapposite.
If the gun in question is to be used, it needs to be rebarrelled. Period. If that's too pricey, the guy intending to use it should price hand surgeons for comparison, then think again.
fiery, dependable, occasionally transcendent
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Sidelock
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Sidelock
Joined: Dec 2001
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The subject gun I am considering purchasing has 3 bulges in the right barrel, according to seller. From the breech - 14", 15 1/2" and 17". The first two are just 'barely' noticeable acc. to seller. The 17" is more pronounced. When I read this last addition to the thread my first thoughts were the wave pressures Drew Mentioned from Burrard. However in Burrard's notation each bulge was smaller as it got further down the barrel. In this case the l farthest (17") is the larger so it seems doubtful these all occurred with just one shot. I would doubt there is enough difference in wall thickness from 14" to 17" to allow a greater bulge at 17" with a lower pressure than at 14".
Miller/TN
I Didn't Say Everything I Said, Yogi Berra
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Joined: Jan 2006
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Sidelock
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Sidelock
Joined: Jan 2006
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I found this old thread about 'bulges.'
The subject gun I am considering purchasing has 3 bulges in the right barrel, according to seller. From the breech - 14", 15 1/2" and 17". The first two are just 'barely' noticeable acc. to seller. The 17" is more pronounced.
The subject gun is a graded gun not only with the barrel issue of bulges but needs wood work as well. Wood can be fixed. Dents can be raised. But will there always be an inherent problem in the bbls if the bulge is repaired?
He does not know bwt nor has the tools to measure. No inspection or return. As-is.
I don't want to waste 2K but I do have another set of bbls that could possibly be fitted to subject gun.
Can bulges be fixed and barrels still be considered safe? Don't drink the cool aid....
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Joined: Feb 2004
Posts: 13,879 Likes: 15
Sidelock
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Sidelock
Joined: Feb 2004
Posts: 13,879 Likes: 15 |
Chuck - the engineering info you present is both spot on and quite correct. I would not, however, rely too much on it in the context we're talking about: a bulged barrel. The long and short of my reluctance (or objection) is that the information you're presenting is derived from carefully prepared laboratory tests run under controlled conditions. OTOH getting a gun to the stage of having a bulged barrel and now deciding whether to use it are not. They don't even rise to the level of a shadetree gunsmith tying a gun to a spare tire and firing it with a rope to see if it will blow up.
Other than illustrating ... something ... comparing a double with a bulged barrel to a Model 12 or other single-barrel is inapposite. There's a lot more going on with the double particularly, as noted above, under the ribs. Moreover, comparing this gun - with the bulge in the area of highest pressure 1/2 inch past the chamber - to any gun with a bulge near the muzzle - the low-pressure end - is likewise inapposite.
If the gun in question is to be used, it needs to be rebarrelled. Period. If that's too pricey, the guy intending to use it should price hand surgeons for comparison, then think again. Dave, Engineering data is practical application data. There are qualifications for its use. I mentioned a principal qualification...being crack free. One I didn't mention was measurement for elongation. That data can provide good perspective on where the metal is on that stress-strain curve (how much strain has occurred). This is all factual data and people put their lives in the hands of this applied data when using engineered products every day. However, if people don't have a good understanding of the data, it's qualifications, and confidence in applying such data, they shouldn't. In the case of a barrel bulge, a layperson may not have the knowledge to understand what is necessary to make the assessment of the actual condition of the metal or select and apply the appropriate data. , That's to be expected. What surprises me, particularly on barrel bulges, is the perpetuation of heresy as fact, when actual engineering data is provided.
Last edited by Chuck H; 01/11/16 12:22 AM.
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Joined: Mar 2006
Posts: 509 Likes: 3
Sidelock
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Sidelock
Joined: Mar 2006
Posts: 509 Likes: 3 |
Subject shotgun is now in my possession. From sellers description and phone conversation, I was expecting B-U-L-G-E-S. Man was I glad to see what I would call pimples.
Seller was off on measurements. 1st - 13 1/2 from breech; 2nd - 15.25; 3rd - 18.5.
Measurement taken with my crude caliper:
Elongation - 1st - .159 ; 2nd - .185 ; 3rd - .195
Rise : 1st - .003 ; 2nd - .004 ; 3rd - .006
Location as if the bbl were on the receiver looking down the left tube: 1st - 7 o'clock ; 2nd - 7 o'clock ; 3rd - 5 o'clock.
These are not ring bulges, just pimples. Hopefully the ribs won't have to be stripped and relaid, but if they do, they do.
Anyone think the bbls are fixable?
If so, looking for smith recommendations.
Last edited by RedofTx; 01/21/16 07:03 PM. Reason: spellin'
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Joined: Mar 2006
Posts: 509 Likes: 3
Sidelock
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Sidelock
Joined: Mar 2006
Posts: 509 Likes: 3 |
Almost forgot. Barrels ring like the proverbial church bell.
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Joined: Jan 2002
Posts: 737 Likes: 23
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 737 Likes: 23 |
If they are just pimples, I'd hammer them down with a plug underneath and shoot it.
Anyone who has read Greener's book about hammering down bulges until the gun passed proof would probably agree.
Of course, that's just me. I seem to be getting reckless as I age.
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Joined: Mar 2006
Posts: 509 Likes: 3
Sidelock
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Sidelock
Joined: Mar 2006
Posts: 509 Likes: 3 |
Oh no not me. I'm no smith and I don't pretend to be. I will leave this to the pros and gladly pay their fee.
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