Patent Publication Number: US-7587853-B2

Title: System for fastening the barrel of a rifle having a replaceable barrel

Description:
This invention relates to a system for fastening the barrel of a rifle with a replaceable barrel, the system consisting of a lock frame, into which the barrel socket can be inserted into position and locked by a bolting device. 
   Practice has shown that it is desirable to replace the barrel of hunting guns for different purposes and calibres. Low-calibre guns, such as small-bore rifles in particular, comprising three different cartridges, 22 LR, 22 Win.Mag and the relatively recently launched model 17 HMR, lead to a need for using all of these in the same gun. 
   In prior art, the barrels are clamped into a split lock frame around the barrel socket by means of two or more clamping screws. The purpose of this invention is to provide a new type of system for fastening the barrel of a rifle with replaceable barrel, which is characterised by the bolting device comprising a barrel block stop in the top of the locking frame, a groove in the barrel socket being insertable into this stop when the barrel is clamped into locking position. 
   Various embodiments of the invention are described in the dependent claims of the set of claims. 
   The invention allows for rapid, reliable and simple replacement of the barrel of a rifle with the desired calibre barrel. Should the barrel for some reason fail to settle in the correct place, the operating system of the gun becomes inoperative. The bolt lock and the cartridge extractor should necessarily settle correctly, and this happens on the sole condition that the barrel has been correctly clamped in position. 

   
     The invention is explained by means of an example below, with reference to the accompanying drawings, in which 
       FIGS. 1 ,  2  and  3  illustrate the installation of the barrel in the gun, 
       FIG. 4  illustrates the same as  FIG. 2 , being a partial enlargement and section of the lock frame, and 
       FIG. 5  shows a part of  FIG. 4  with the barrel in locked position. 
   

   The system for fastening the barrel  1  comprises a lock frame  2 , into which the barrel socket  5  can be inserted into position and locked by a bolting device. The bolting device comprises a stop  4  for blocking the barrel  1  provided at the top of the lock frame  2 , a groove  6  in the barrel socket  5  being insertable into the stop when the barrel is clamped into locking position. The block stop  4  is a separate tempered arcuate claw fastened to the lock frame  2 . The arcuate portion fits into the groove  6  provided in the socket  5  of the barrel  1  in the locked position, being prevented from moving forwardly. On the opposite side of the block stop  4 , the lock frame  2  comprises a spring-loaded  7  support plate  9 , under which a screw  9  is provided for clamping the socket  5  of the barrel in the lock frame upwardly against the block stop  4 . The opening of the lock frame  2  is shaped so as to allow the barrel socket  5  to be pushed into the lock frame  2  at a small angle, with the flange portion  3  of the groove in the barrel socket being allowed to pass by the block stop before the barrel is clamped into position. The lower side of the barrel socket  5 , which bears against the support plate  8 , has been worked to a planar surface, so that he barrel settles at the correct angle around its axis during installation and clamping. The compression force exerted on the barrel socket will also be more regular when the locking screw  9  is tightened. One single tool, such as an ordinary hex key, is needed for the replacement of the barrel.