SIG AMT

SIG (Schweizerische Industrie-Gesellschaft) · Battle Rifle · Discontinued · 1960

Also known as: SG 510, SG 510-4, Stgw 57, American Match Target, AM 55

Overview

The SIG AMT (American Match Target) is the semi-automatic civilian US-export variant of the SIG SG 510-4 - itself the 7.62×51mm NATO export version of the legendary Swiss Stgw 57 battle rifle designed by Rudolf Amsler. The SG 510 family employs a roller-delayed blowback system derived from the wartime Mauser StG 45(M), but where the German design used true rollers, the Swiss substituted pivoting flaps for tighter tolerances and longer service life. Imported into the United States between 1969 and 1989 in numbers estimated at roughly 3,000, the AMT delivered Swiss-watch-grade machining, integral folding bipod, perforated barrel jacket, winter trigger, and renowned softness of recoil to American shooters at then-staggering prices ($1,700 by 1978). Reviewers consistently rank it among the finest 7.62×51mm semi-auto battle rifles ever produced - outshooting contemporaries like the HK91 and FN FAL with ~2 MOA accuracy from iron sights.

Specifications

Weight (empty)4500 g (158.7 oz)
Overall Length1016 mm (40.00")
Barrel Length505 mm (19.88")
Sight Radius533 mm (20.98")
Action TypeRoller Delayed Blowback
Firing MechanismHammer Fired
Trigger TypeSingle Stage
Magazine Capacity20 rounds
Magazine TypeDetachable Box
Muzzle Velocity838 m/s (2749 fps)
Muzzle Energy3300 J (2434 ft·lbf)
Effective Range500 m (547 yd)
Maximum Range600 m (656 yd)
Barrel RiflingRight Hand
Rifling Twist305 mm (12.01")
Number of Grooves4
Frame MaterialSteel
Barrel MaterialSteel
Stock MaterialWood
FinishParkerized

Calibers

Features

Variants

Base model

Sig-Stgw-57

Service history

Operators

Production

Estimated total produced: 3,000 · Production years: 1960-1983 (SG 510 family); 1969-1989 US imports

1,440 confirmed US imports 1969-1978; estimated ~3,000 total. US importers included Benet Arms, SARCO, Osborne Brothers, Mandall, SIGARMS, Golden State Arms.

Origin

Country of origin: Switzerland

Designer: Rudolf Amsler

Discontinued: 1989

Notes

AMT is the civilian US-import semi-auto only variant; military Stgw 57 / SG 510-4 are select-fire. Source variance on weight: ModernFirearms 4.25 kg (510-4 base) vs biggerhammer.net 4.5 kg (AMT) - likely reflects French walnut furniture density. Approximately 1,440 confirmed imports 1969–1978; estimated ~3,000 total before 1989 import ban. SG 510 family production ended 1983.

Background

Reportedly one of the most expensive infantry rifles ever fielded - the Stgw 57 served the Swiss Army from 1957 until replaced by the SG 550 in 1990. The pivoting-flap roller-delayed system traded straight-roller wear for Swiss-watch tolerances, and the perforated barrel jacket plus integral bipod gave it a distinctive silhouette unmistakable on a 1980s American gun-show table.