BREECH MECHANISM FOR BOLT-ACTION FIREARMS

Abstract: The invention relates to a breech mechanism in a bolt-action firearm, consisting of a breech body (2) reciprocating in the receiver (1) and rotatable into locking position, and having on its front portion a locking lug (3, 4, 5) placed in three sectors. The locking lugs (4, 5) in at least two sectors have been formed in a breech mechanism provided with a parallel loading magazine (6) such that there are four guide surfaces (7, 8, 9, 10) limiting breech rotation between the receiver (1) and the breech body (2).

Description: Breech mechanism for bolt-action firearms This invention relates to a breech mechanism for a bolt-action firearm, the breech mechanism consisting of a breech body reciprocating in the receiver and rotatable into locking position, having in its front portion a locking lug placed in three sectors. In all bolt-action systems known per se, either complete breech control or parallel loading have had to be sacrified so far. There are generally three guide surfaces, and it has been found that the breech mechanism tends to swerve when being opened or closed. The purpose of the invention is to achieve a breech mechanism of a new type for a bolt-action firearm, which is free of the inconveniences mentioned above. The breech mechanism of the invention is characterised in that the locking lugs in at least two sectors have been formed in a breech mechanism provided with a parallel loading magazine such that there are four guide surfaces to limit rotation of the breech mechanism between the receiver and the breech body. Four guide surfaces provide notably better control of the breech mechanism than solutions known per se. The solution of the invention also enables a loose magazine to be filled without the magazine being detached from the iireaixri, and thus cartridges can be inserted in the magazine from above, as in a conventional magazine. One embodiment of the invention is characterised in that the guide surfaces are located in the lower locking lugs of the sector and symmetrically on each side of the breech body. A second embodiment of the invention is characterised in that the lower locking lugs have longitudinal grooves, which form two lower guide surfaces, and in that the upper surfaces of the lugs form two upper guide surfaces. The invention will be described below by means of an example and with reference to the enclosed drawings, in which figure 1 is an axonometric view of the front portion of the bolt action figure 2 is a cross-section of the breech mechanism of the bolt action and figures 3-6 illustrate bolt-action solutions known per se. The breech mechanism consists of a breech body 2 reciprocating in the receiver 1 and rotatable into locking position, and having in its front portion a locking lug 3, 4, 5 located in three sectors. The locking lugs in two sectors 4, 5 have been formed in a breech mechanism provided with a parallel loading magazine 6 such that there are four guide surfaces 7, 8, 9, 10 limiting breech rotation between the receiver 1 and the breech body 2. The guide surfaces 7, 8, 9, 10 are located in the lower locking lugs 4, 5 of the sector and symmetrically on each side of the breech body 2. The lower locking lugs 4, 5 have longitudinal grooves 11, 12, which form lower guide surfaces 8, 10 and the upper surfaces of lugs 4, 5 form upper guide surfaces 7, 9. The hook 13 shown in figure 1 is a cartridge or shell extractor and the striking pin opening 14 is in the centre.

Claims: Claims 1. Breech mechanism for a bolt-action firearm, consisting of a breech body (2) reciprocating in the receiver (1) and rotatable into locking position, and having on its front portion a locking lug (3, 4, 5) placed in three sectors, characterised in that the locking lugs (4, 5) in at least two sectors have been formed in a breech mechanism provided with a parallel loading magazine (6) such that there are four guide surfaces (7, 8, 9, 10) to limit breech rotation between the receiver (1) and the breech body (2). 2. Brech mechanism as claimed in claim 1, characterised in that the guide surfaces (7, 8, 9, 10) are located in the lower locking lugs (4, 5) of the sector and symmetrically on each side of the breech body (2). 3. Breech mechanism as claimed in claim 1 and 2, characterised in that the lower locking lugs have longitudinal grooves (11, 12) which form two lower guide surfaces (8, 10) and in that the upper surfaces of the lugs (4, 5) form two upper guide surfaces (7, 9).

Inventors: AALTO JUHA, AALTO, JUHA
Applicants: AALTO JUHA, SAKO OY, AALTO, JUHA
Application year: 1996
Main classification: F41A3
IPC codes: F41A3