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Forums10
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Joined: Mar 2011
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Sidelock
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OP
Sidelock
Joined: Mar 2011
Posts: 2,978 Likes: 105 |
Many fine guns have barrels made of chopper lump, dove tail or demiblock construction. For example, many English guns such as Purdey are of chopper lump. Some American guns such as Winchester 21 are similar to chopper lump, but use a dove tail method. Browning superposed are of demiblock construction. These methods are all very similar and differ from monoblock construction in that with monoblock there is a weld point just anterior to the chamber where barrels are joined to the monoblock. Examples of this sort of construction are many such as beretta, browning citori and Perazzi just to name a few. Certainly, no one would argue that monoblock is a much cheaper method than the others. Sometimes however, cheaper methods can be better. Which methods do you consider better in terms of strength and safety?
Socialism is almost the worst.
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Joined: Jan 2002
Posts: 1,393
Sidelock
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Sidelock
Joined: Jan 2002
Posts: 1,393 |
About equal in all respects, I'd say Mike
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Joined: Dec 2001
Posts: 3,553
Sidelock
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Sidelock
Joined: Dec 2001
Posts: 3,553 |
I really have come to not like the Beretta & others way of making the joint line on Mono construction so very visible,with a ring of "engraving".I would of thought they would be able to do a "seamless" job? Franc
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Joined: May 2010
Posts: 1,520 Likes: 71
Sidelock
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Sidelock
Joined: May 2010
Posts: 1,520 Likes: 71 |
For a side by side ,choppres are certainly the strongest and with modern production methods on prodution guns I can not see that there sould be any difference in cost .The tubes themself will cost more to produce but this would be compensated for in the,reduction of cost in the assembly,due the the methods used, Cheap Spanish guns are good example . This is not to be confused with hand build barrels for high grade guns . As far as O/U's go ,using a mono block that can be precsision cast will cut machining time down thus reducing the overall cost to the customer. Up untill now there has been very little trouble with mono block barrels ,considering the number that have been produced.They are also expected to stand up to much heavier loads and to more prolonged useage than guns of an earlier generation .But then again manufactureres are not expecting these guns to last for a century.It is not in there interest to do so.
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Joined: Nov 2005
Posts: 4,598
Sidelock
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Sidelock
Joined: Nov 2005
Posts: 4,598 |
Pieper invented the Monobloc, 1881. The barrels were screwed into the breech. His patent required a band on the muzzles. His company moved to the demibloc after his death. I believe at the time, it was the cheaper method. So, by 1900 the demibloc was in use by Pieper. Beretta adopted the monobloc in 1913, if Wilson is correct. I know there no Beretta guns that use it in a 1910 catalog. Another early user was Darne. http://damascus-barrels.com/uspatentnom.htmlhttp://www.google.com/patents?id=QiBMAAA...p;q&f=falseSears 1897 catalog. In this 1932 Beretta catalog, the M1010 is clearly a monobloc. This is a 1938 Beretta catalog. It appears the barrels are soldered or brazed. This is not a monobloc, but you get the idea. Personally, I only care that it has passed proof. Pete
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Joined: Dec 2001
Posts: 12,743
Sidelock
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Sidelock
Joined: Dec 2001
Posts: 12,743 |
In Pieper's original patent the bbls were not threaded in to the breech piece (mono-block). The breech piece had tapered holes through it & the bbls were inserted from the rear & seated in the tapers. There was thus a step down at the forward end of the breech piece, or what we generally refer to today as "Fretted". The tubes being turned down & threaded in to the breech piece & giving a smooth joint came at some later point. I do not know who, but suspect someone patented this method. One of the big "Bragging Points" of the mono-block was it did not require brazing heat to assemble, but was a combination of mechanicl & soft solder, but had far greater strength than a normal assembly would if done with only soft solder. Conventional, Dovetail, Chopper & Shoe lumps all require brazing heats for maximum joint strength. The dovetail chopper lump as on the M21 & some others does not require brazing as the two are mechanically held together & pinned to prevent shifting. They can thus be soft soldered to complete the joint with no fear of bbl seperation.
Note that all of this has only to do with the strength of the connection between the two bbls & does not pertain to strength as regards to handling pressure of firing nor the connection of ribs etc.
Pieper did use a band at the muzzle in his oroginal patent, to say it was a "Requirement" is I think stretching the point. The Pieper hammer gun I have built with the later method of screwing in the bbls does not have a muzzle band. Also on mine the bbls have short stubs which extend only about half way through the breech piece, not all the way as on those pictured. He seems to have used several methods over the years. Mine is marked Modified Dianna. A 1911 "Alfa" catalog still lists Pieper guns made on the mono-block principal, though they are simply referrd to as having a one-piece steel breech piece. I so far have never seen a reference to Pieper using the term mono-block.
Miller/TN I Didn't Say Everything I Said, Yogi Berra
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Joined: Nov 2005
Posts: 4,598
Sidelock
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Sidelock
Joined: Nov 2005
Posts: 4,598 |
The patent specifies link C. So if it part of the patent there is no stretching. The double gun-barrel and joining means as described, consisting of the barrels b1, b2, breechpiece a, a1, a2,strips d e, and link c, substantially as set forth. Certainly they kept changing the methods after Henri Pieper's death. If they modified the patent when their methods changed as would be usual, I can not tell. Neither his patent nor the documents he submitted in Paris specify how the tubes are held in place. Here are two images from a Société Anonyme Anciens Pieper Establissments (AEP) 1911 catalog Long after his death, the company is still producing the Diana, the 1881 patent, monobloc As well as this demibloc model. I own a Diana (c 1883), a Modified Diana (c 1895), a later demibloc (1925) and a very late (1947) demibloc. When he was alive, Henri Pieper was a bit of a tinker. He was constantly experimenting with means to cut out steps and increase the automation of his factory. Pete
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Joined: Mar 2011
Posts: 2,978 Likes: 105
Sidelock
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OP
Sidelock
Joined: Mar 2011
Posts: 2,978 Likes: 105 |
This is all extremely interesting to me. I was very unaware that monoblock has been around since the late 1800's. The Beretta Monoblock almost appears like that of modern day 'sleeving'. Is there any difference?
Socialism is almost the worst.
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Joined: Dec 2010
Posts: 691 Likes: 7
Sidelock
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Sidelock
Joined: Dec 2010
Posts: 691 Likes: 7 |
Would someone please describe the differences between chopper lump and demi-bloc construction in S x S guns? I thought they were different terminologies for the same thing.
Wild Skies Since 1951
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Joined: Feb 2003
Posts: 1,623 Likes: 13
Sidelock
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Sidelock
Joined: Feb 2003
Posts: 1,623 Likes: 13 |
Mr. Miller: You are amazing. There is hardly a subject that comes up that you cannot contribute to in a meaningful way. I am printing your input on this subject and putting it in the file. And Pete from Illinois, your stuff is always interesting too. Thank you both!
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