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Joined: May 2004
Posts: 778 Likes: 36
Sidelock
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Sidelock
Joined: May 2004
Posts: 778 Likes: 36 |
As there has been a flurry of postings about re-proofing guns, I thought I should give a heads-up on a rather worrying development at the UK proof houses.
Lately there had been rumours of guns 'unexpectedly' failing proof including some from our most illustrious makers which I doubt is a common occurrence!
Although there have been tales of actions failing, it seems that the majority of these failures have been caused by barrels bulging just behind the chokes. The choke constrictions in these cases have apparently all been in excess of a UK 1/2 or 0.020" and all instances have been with 12b guns, smaller bores seem unaffected.
After several 'unexpected' failures, one barrel specialist asked for a formal investigation of the proof loads that were being used as it is alleged that the start of these problems coincided with a change in the sourcing of the loads used by both Proof Houses. The subsequent reply from the Proof House confirmed that they had tested their proof loads and had found no problems with them.
I have heard it suggested that as they test pressure only at 1" and 6" from the breech face, they are most likely looking in the wrong place but not being a ballistic expert I do not know if this hangs together.
I would stress that I have not been a victim of this problem, in fact I have never had a gun fail proof 'unexpectedly', maybe because I seldom work on guns with heavy choke, and I am sure that the proof houses are working hard to discover if there really is a problem. However, I feel that now is perhaps not the best time to be considering a re-proof of your pride and joy! Best to wait until this has all been sorted out.
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Joined: Apr 2005
Posts: 1,688 Likes: 31
Sidelock
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Sidelock
Joined: Apr 2005
Posts: 1,688 Likes: 31 |
Toby, Are we talking London Proof, Birmingham Proof or Both?
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Joined: May 2004
Posts: 778 Likes: 36
Sidelock
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OP
Sidelock
Joined: May 2004
Posts: 778 Likes: 36 |
Peter, I am told both, I'm afraid. Apparently the proof cartridges are being loaded by the Birmingham House for both London & Birmingham. Toby
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Joined: Jan 2002
Posts: 11,383 Likes: 106
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 11,383 Likes: 106 |
Odd place for failures. Pressure is significantly reduced that far down the barrel.
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Joined: Nov 2002
Posts: 9,381 Likes: 1
Sidelock
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Sidelock
Joined: Nov 2002
Posts: 9,381 Likes: 1 |
Don't worry Mr. Barclay in America we use Remington Nitromags long string and car tire from behind thick oak trees.
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Joined: May 2010
Posts: 1,530 Likes: 82
Sidelock
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Sidelock
Joined: May 2010
Posts: 1,530 Likes: 82 |
A good reason for more open chokes?
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Joined: Jun 2008
Posts: 2,737 Likes: 96
Sidelock
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Sidelock
Joined: Jun 2008
Posts: 2,737 Likes: 96 |
Odd! The sort of thing that you would expect from using steel shot and tight chokes. Lagopus.....
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Joined: May 2004
Posts: 778 Likes: 36
Sidelock
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OP
Sidelock
Joined: May 2004
Posts: 778 Likes: 36 |
Lagopus, I couldn't possibly comment! However, someone did suggest examining the cases of proof cartridges with a magnet! Other suggestion is a highly progressive powder: fine at 1" and 6" but pressure still growing all the way to the choke. What do I know, I'm only a rank amateur.
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Joined: Feb 2005
Posts: 7,438
Sidelock
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Sidelock
Joined: Feb 2005
Posts: 7,438 |
So is it a fair assessment that right after abuse and neglect the greatest danger to old doubles are the British proofing houses? Jim
The 2nd Amendment IS an unalienable right.
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Joined: May 2004
Posts: 778 Likes: 36
Sidelock
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OP
Sidelock
Joined: May 2004
Posts: 778 Likes: 36 |
Again, I couldn't possibly comment!
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