Device for applying subcaliber barrels to revolvers of the solid-frame swing-out cylinder type

Application filed January 26, 1932, Serial No. 588,901, and in Spain December 16, 1931.

The device of the present invention serves to reduce the caliber of revolvers of the solidframe, swing-out-cylinder type, so that a large-caliber revolver may be used for firing cartridges of smaller caliber.

Said device is represented, merely by way of example, in the accompanying drawing, in which Fig. 1 is a side view of the subcaliber barrel; Fig. 2 is a perspective view of a block that takes the place of the cylinder of the revolver; Fig. 3 is a representation of the same block, seen from the opposite side; Fig. 4 represents the device applied to a revolver, and Fig. 5 illustrates a variation.

The sub-caliber barrel 1 (Fig. 1) is a cylindrical rod bored, rifled and chambered for the reduced-caliber cartridge to be employed, the bore being represented by the number 2. This barrel has on the outside two cylindrical collars, or bushings, 3 and 4 of such diameter as to enter exactly into the barrel of the revolver, as represented by the dotted lines in Fig. 4.

The piece that replaces the cylinder (Figs.

²³ 2 and 3) has the form of a block 6—7, the longer arm of which 7 intersects the shorter 6, forming a right angle at 8. The shorter arm 6 of the block has a bore 9 with inside screw thread, into which can be screwed the ³⁰ threaded chamber-end 10 of the sub-caliber barrel (Fig. 1), when the block occupies the cylinder space of the revolver, the sub-caliber barrel having been previously passed through the revolver barrel from the muzzle ³⁵ 5. The threaded end 10 of the sub-caliber barrel (Fig. 1) is that which contains the chamber.

When the block of the device occupies the cylinder space of the revolver and is in position for firing, the center of the bore 9 coincides with the axis of the revolver barrel and the firing-pin-hole of same, if the cartridge for which the sub-caliber device is adapted is center-fire. If this cartridge is ⁴⁵ rim-fire, the perforation 9 is somewhat lower, so that the firing-pin-point of the hammer will strike on the cartridge rim.

The shorter arm 6 of the block of the subcaliber device has on its outside, or rear, surface a flat, cup-like projection 12 to engage to in the cylinder lock 13, if the revolver is of the Colt system; and for revolvers of the Smith & Wesson system it has a projecting pin with rounded point (Fig. 5, Num. 14), which can be depressed, since its base 17 rests upon a spiral spring 15 and is held in place by a screwed plug 16, through which it passes. The pin engages in the cylinder lock of Smith & Wesson and other revolvers of similar construction.

These projections 12 and 14 on the rear surface of the block to engage in the cylinder lock of the revolver serve to hold the block 6—7 firmly in place, while the sub-caliber barrel (Fig. 1), which Js screwed into it, passes through the bore of the revolver.

When the device is in the locked, Or firing, position the notch 18 on the long arm of the block 6--7 engages with the forward inside surface of the cylinder space of the revolver (opposite the recoil plate) and this holds the rear projection 12 or 14 firmly in the cylinder lock 13, so that block and sub-caliber barrel are kept rigid.

If the cylinder lock 13 is opened and the long arm of the block 7 is pushed from the right side of the revolver towards the left, the block swings out; the notch 18 disengages from the frame, and the whole device can be moved a short distance forward, the sub-caliber barrel sliding through the bore of the revolver. This leaves the rear portion of the device free for knocking out the fired cartridge with a metal rod passed through the barrel and for inserting a new cartridge into the chamber 10.

Fig. 3 shows how the rear sight 19 for reduced caliber practice can be attached to the block 6 by means of a set screw 20 without need of removing the sight from the block or changing the adjustment of the sight when the device itself is removed from the revolver. The set screw 20 passes through a vertical slot 21 which allows the base of the sight to be moved upward and downward. This same movement may be obtained by means of a ratehet.