SIG SG-540
Overview
SG-542
SIG SG-542 battle rifle with fixed stock.
Source: www.gun-world.net -
© Copyright lies with original owner
Chile - FAMAE (? - 2002)
Portugal - INDEP
Design
Introduction
The SG-540 is a Cold War era assault rifle of Swiss origin. The design has many elements of the SG-530 prototype, which was not taken into production due to its costly roller locking mechanism. The SG-540 was developed as a much cheaper alternative. The later and higher quality SG-550 was based on the SG-540 design.
Design
The SG-540 has a conventional layout. To keep costs down it has a two piece stamped metal receiver and it uses a long stroke gas piston and rotating bolt. The forearm is made of plastic and a plastic fixed butt or folding metal butt is fitted. The three position gas piston allows use in harsh conditions and the firing of rifle grenades. A bipod that folds along the forearm is standard.
Firepower
The SG-540 fires the 5.56x45mm M193 round from 20 or 30 round magazines. It is a select fire weapon with single shot, burst fire and fully automatic capability. It has a cyclic rate of fire of 650 to 800 rounds per minute, varying due to fouling and gas regulator setting. The SG-542 variant fires the more powerful 7.62x51mm round from 20 round magazines. By closing the gas regulator rifle grenades can be fired.
Users
The SG-540 has been sold to many nations, but mostly in limited quantities. Most customers are African and South American nations. The vast majority of SG-540 were produced in France due to strict Swiss export regulations. It was never adopted by Swiss forces.
Variants
SG-540
The SG-540 is the standard full size assault rifle variant. It fires the 5.56x45mm M193 round from 20 or 30 round magazines. It is fitted with a fixed plastic stock. The SG-540-1 has side folding metal stock. A bipod that folds along the forearm is standard.
SG-542
The SG-542 is the battle rifle variant of the SG-540. It is similar in most aspects, but fires the 7.62x51mm round from a 20 round magazine. Due to the heavier recoil the SG-542 is mostly fitted with the fixed plastic stock. A bipod that folds along the forearm is standard.
SG-543
The SG-543 is the carbine version of the SG-540. It has the same design as the SG-540, but features a shorter forearm and barrel. Unlike the full size SG-540 it is not available with a fixed stock, the side folding metal stock is standard. There is no bipod mounted under the forearm.
Details
Related articles
Colt M16A1
Together with the American M16A1 the SG-540 is one of the rifles that introduced widespread use of the 5.56x45mm round before adoption by NATO.