Demi-bloc and chopper lump barrels both involve joining two halves of the barrels, top and bottom for an O/U and each side for the side x side, to make the barrel set. There are two styles of jointing barrels that utilize full-length single-piece barrel + lump construction. These guns can usually be produced with less final hand fitting which can lower manufacturing cost (but not necessarily quality). The final fitting required on a mono-bloc gun is typically less than others. The biggest advantage is allowing the complex (and very co-dependent) angles to be machined into the action with a high degree of accuracy. Mono-bloc barrels are formed by machining the chamber portion or lump from a single solid piece of steel by take advantage of modern precision engineering and manufacturing techniques. In some cases, the barrels are separate pieces and a third piece is joined to create the lump illustrating the diversity of manufacturing possibilities. In this case, the lump is machined after the barrels are joined together. Those blocks of steel mate together when two barrels are joined and thus the lump is formed. That is to say that each barrel contains a block of metal on the breech end of the barrel half the size of the lump. Or the lump can be formed during the jointing process. The lump can be created from a single solid piece of steel without barrels connected upon which barrels are added after machining the lump by sleeving and braising. What I will refer to as the lump or breech bloc contains the lockup surfaces, ejector/extractor channels, the breech face and all associated elements. The breech end of the barrels is commonly called the breech bloc or lump, though the ‘lump’ or ‘lumps’ may refer to individual surfaces that lock an action shut. Needless to say, jointing double gun barrels happens in two ways, but terminology first. There are very few folks in the states that will even take on the task of regulating a double rifle, the process of ensuring a proper cross at a specific distance with particular ammunition (side by side or over/under). In terms of double rifles, this is exceptionally important and ‘regulation’ of these guns is perhaps one of the most mythological and mystifying procedures I have heard folks speak about in the gun world. This convergence allows a single targeting sight plane to function for both barrels. For both double rifles and shotguns, the barrels are laid such that the trajectory of a bullet or shot from the bores crosses that of the opposing barrel downrange at some specified distance. In terms of geometry, if we think about any gun with two barrels, it may be a first intuition to think that the bores are parallel to one another.
Break action doubles like your Beretta 686, Parker or Holland and Holland double rifle all have barrels that have been jointed together without threading a barrel. A gunsmith will painstakingly cut these threads until proper headspace, or fit between action, bolt and barrel is achieved.ĭouble guns are in general manufactured differently, although there are always exceptions. The threaded barrel is similar to a screw that threads into the same pitch threads in the action. With the exception of double rifles, which fall into the larger category of ‘double guns’ a vast majority of modern rifle barrels are fitted to their actions via barrel threads. As we dive into and explore the construction of modern guns, we quickly begin to see a great diversity of techniques developed over the last 200 years or so that illustrate just how much thought has been put into the construction of the shotguns and rifles we love.
As hunters or shooters, finding a gun that fits, breaks clays or kills birds is foremost in our mind. It is, at times, easy to take for granted the complexity of manufacturing involved in creating a fine sporting rifle or shotgun. Exploring mono-bloc, demi-bloc and chopper lump barrels
0 kommentar(er)
