These are original British Armourers Gauges for testing the Gib of .303" Vickers MMGs.
An unusual gauge which is rarely seen, these are similar in appearance to .303" headspace gauges, these gauges are made with a rim thickness of only 0.058". This measurement is the absolute minimum rim thickness for a .303" round.
The 'Gib' is a component of the extractor on the Vickers lock (breech block). It is a bar with a claw on it's front face which can be seen protruding from the front face of the lock, in the centre of the extractor slot above the firing pin hole (see picture 2 where the Gib is highlighted in red). It's job is to control the round from when it is extracted from the belt, controlling it in the extractor slot until it is chambered, at this point the extractor returns to the top of the lock to pick up the next round from the belt. The Gib is held forward under tension by a flat spring.
The gauge is used to simulate a minimum thickness rim on a round. It is placed on the lock and must remain held firmly against the front of the extractor slot by the Gib under the forward pressure of it's spring. Looseness of the gauge in the slot would indicate that the Gib or it's spring were worn or faulty and that they should be exchanged.
The gauges are in good clean condition. All are marked on the base 'Y No202'.
The lock shown in the pictures is for illustrative purposes only and is NOT included in the sale.
Unit of sale 1 gauge. British Army Part No SM178. Stock No ARMRSTOOL69.
Note; As we cannot be sure of the exact calibrated measurements of any small arms gauges due to age, provenance, wear & tear etc, ALL gauges sold (unless specified) are sold as collectors curios only and we do not offer any guarantees as to their servicability or ability to be used for their original or intended purpose.
British Armourers Gauge Testing .303" Vickers MG Gib
- Manufacturer: Vickers
- Product Code: ARMRSTOOL69
- Availability: 1