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Forums10
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Most Online1,344 Apr 29th, 2024
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Joined: Feb 2004
Posts: 13,880 Likes: 16
Sidelock
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Sidelock
Joined: Feb 2004
Posts: 13,880 Likes: 16 |
When was the last time anyone had their desk lamp "re-proofed" by UL after they changed the socket base or cord? Where's Italiansxs when he's really needed? Can you imagine a proofhouse in the states in todays volitile gun law environment? Proof records could be abused. This shooting of a dozen people already has the gun control media making their own news about more gun control. Bob Shieffer already threw it out there this morning. How many of you with a 90% Optimus or AHE or LC Deluxe or even a favorite family GH Parker or CE Fox would run down and have someone pump a couple near 20,000 psi rounds thru it and get out a big hammer and a metal stamp and beat on your pride and joy? Not many takers on that, I suspect.
Last edited by Chuck H; 07/20/12 09:40 AM.
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Joined: May 2009
Posts: 156
Sidelock
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Sidelock
Joined: May 2009
Posts: 156 |
When was the last time anyone had their desk lamp "re-proofed" by UL after they changed the socket base or cord? Where's Italiansxs when he's really needed? Can you imagine a proofhouse in the states in todays volitile gun law environment? Proof records could be abused. This shooting of a dozen people already has the gun control media making their own news about more gun control. Bob Shieffer already threw it out there this morning. How many of you with a 90% Optimus or AHE or LC Deluxe or even a favorite family GH Parker or CE Fox would run down and have someone pump a couple near 20,000 psi rounds thru it and get out a big hammer and a metal stamp and beat on your pride and joy? Not many takers on that, I suspect. +1. The high minded "voluntary" approach needs healthy measures of common sense and real politik. The back door initiatives (beaten down so far by an active pro-gun lobby) such as loading component and ammunition regulation and control come to mind. Keep government out, entirely, or we'll rue the day we went along with "voluntary" proofing.
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Joined: Dec 2002
Posts: 292
Sidelock
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Sidelock
Joined: Dec 2002
Posts: 292 |
Why would anyone lengthen a chamber when simply having forcing cones lengthened produce the desired result in most cases with probable better performance?
A Springer Spaniel, a 6# double and a fair day to hunt.
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Joined: Feb 2004
Posts: 13,880 Likes: 16
Sidelock
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Sidelock
Joined: Feb 2004
Posts: 13,880 Likes: 16 |
Erik, I'd be guessing, but it's probably just uninformed pedestrians and gunsmiths. I shoot my damascus guns with 2 3/4" hulls loaded to low pressures in 2 5/8" chambers.
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Joined: Jan 2002
Posts: 11,398 Likes: 108
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 11,398 Likes: 108 |
Why would anyone lengthen a chamber when simply having forcing cones lengthened produce the desired result in most cases with probable better performance? Erik, if "the desired result" is reducing pressure to what you'd get by firing a 2 3/4" shell in a 2 3/4" chamber, the only way to do that is with a 2 3/4" chamber. Sherman Bell's "Finding Out for Myself" tests showed that lengthening the cones usually resulted in some reduction in pressure. However, pressures still remained higher than when the shell was fired in a chamber of the appropriate length. It was usually only a question of a few hundred psi, but still higher. Of course the tradeoff is that removing metal from the chamber (as opposed to just lengthening the cone, which removes very little metal) obviously weakens that area of the gun. That's why the Brits insist on reproof when chambers are lengthened.
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Joined: Dec 2001
Posts: 12,743
Sidelock
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Sidelock
Joined: Dec 2001
Posts: 12,743 |
If one begins measuring thwe wall thickness with an accurate gage, just forward of the rim seat & continues down the bbl the following will be found in a normal gun. The OD of the bbl decreases in diameter faster than the chamber dia so the wall will decrease until the end of chamber is come to. At this point the diameter of the cone decreases faster than the OD so the wall will reverse & begiin to increase until the end of cone is arrived at. Here the bore will remain essentially constant while the OD continues decreasing, so the wall will again begin to decrease. At some point the wall will become equal to that at the juncture of the chamber & cone. The cone can thus be lengthened to this point with no loss of minimum wall thickness. Even if the cone is lengthened more than this the point where the wall becomes thinner than that of the chamber/cone juncture will be moved down the bbl where pressure is dropping so no Danger point is ordinarily established. Thus the British ruling that a gun having a lengthened cone does not need re-proofing. On the other had if the chamber itself is lengthened the OD is still decreasing faster than the chamber so an immediate reduction of wall thickness occurs at the end of the chamber.
A couple of points though worthy of note, The point of maximum pressure is reached inside the chamer itself prior to this point of minimum wall so this does not in most cases actually represent a "Weak" point. Also most American guns were not built to a carefully stuidied out minimum as are some British game guns. Most American guns can actually have the chambers lengthened without encroaching upon the minimum required wall thickness. Of far more real concern is the overall effect of using heavier loads than the entire gun was designed around. Also do not take these comments as a recommendation to rush out & have your chambers lengthened, I do not recommend such. I a book by Roy Dunlap "Gunsmithing" copyrited 1950 he gives minimum chamber dimensions for the 2 3/4" 12ga. He doesn't specifically say so, but I assume these were then current SAAMI specs. Minimum chamber dia was given as .798" with a minimum cone of 5° per side. This calculates to a cone length of .400" to a bore diameter of .728". But, get this, he gave a minimum length from breech to beginning of the cone as 2.6136 or slightly shorter the 2 5/8" (2.625"). Using the minimum parameters the diameter of the cone at a point 2.750" from the breeech would be .024" smaller than the chamber or .774". This chamber was sanctioned for any & all 2 3/4" sheels in guns which were otherwise built for those loads.
Miller/TN I Didn't Say Everything I Said, Yogi Berra
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Joined: Feb 2003
Posts: 4,047 Likes: 54
Sidelock
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Sidelock
Joined: Feb 2003
Posts: 4,047 Likes: 54 |
I just saw an American made gun survive 'proof'
A friend, and very experienced handloader just fired off a major overcharge in a Ruger revolver. This is one of the new ones, in 357.
He was shooting 38 special cases, had a squib, and several rounds later found the rest of the powder in another load.
The gun barked a bit... and we had to drive the case out of the cylinder. This was very difficult. It was ironed in tight.
He went home and weighed the rest of the 3,000 loads he had on hand (yes, 3,000). All suspect ones were disassembled. No overcharges found.
I suspect ANY American made pistol will survive this kind of torture, and any of the few shotguns made here are just as stout.
We don't seem to have a big problem with US made firearms blowing up.
"The price of good shotgunnery is constant practice" - Fred Kimble
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Joined: Mar 2012
Posts: 348 Likes: 6
Sidelock
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Sidelock
Joined: Mar 2012
Posts: 348 Likes: 6 |
Back in the late '60s while shooting skeet in western OK I had the unpleasant experience of firing a hand load (someone else's load) that had apparently a double powder load in it. BIG bang and knocked me back against the low house. Everyone thought I had fired both barrels at the same time...which I had not. The barrel (left one) was bulged in the chamber area with the center of the bulge pretty much in line with the center of the chamber. I would not care to try that again!!
Sam Welch
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Joined: Jan 2002
Posts: 11,398 Likes: 108
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 11,398 Likes: 108 |
We don't seem to have a big problem with US made firearms blowing up.
I recently saw the aftermath of a 20ga Fox ejector gun with the R chamber blown. Peeled away from the outside (where the pin on the ejector luggers runs through the frame) in towards the rib. That's the opposite of the way it happened with the first Parker Bell blew, which peeled out from the middle--starting from where the big pin on the extractor lugger runs underneath the rib. In both cases, the holes where those pins ride are obviously weak spots--although, as Bell's test showed, usually well capable of withstanding extreme overpressure loads. A double charge may have been at fault in the case of the Fox. Reloads, and the shooter later found one or two with no powder.
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Joined: Feb 2004
Posts: 13,880 Likes: 16
Sidelock
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Sidelock
Joined: Feb 2004
Posts: 13,880 Likes: 16 |
Just my thoughts, but if creating a law with the intent of preventing gun failures were the goal, I would think that outlawing reloading would be the most effective.
I'm not saying I'm for it, just that most failures I've seen were related somehow to reloading.
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