THE SIG AMT: THE FINEST 7.62X51 MM NATO BATTLE RIFLE EVER MADE.
A roller-delayed action similar to that of the G3 rifle was chosen. To ease production, steel stampings were used for many parts. Its detachable box magazines held 24 rounds. Its stock is of straight-line design, which necessitates the use of folding rear and front sights. These sights are quite high; hence, folding them is advisable during movement to avoid damaging them. During development between 1954 and 1957, the new rifle was designated the SIG 510. The 510-1 version was adopted by the Swiss Army in 1957, and designated the Sturmgewhr 57 (Stgw 57). As befits the rifle for a nation of marksmen, the Stgw 57 was quite accurate, with sub-MOA expected
The AMT is well-designed for firing from the prone position using the built-in bipod. to at least 300 meters. The iron sights are very good for a battle rifle, though in my opinion not as good as the diopter rear sight on the Stgw 90 (SIG 550), the rifle that replaced the Stgw 57. Longer barrels meant longer range in the Alps, so the Stgw had a 23-inch barrel and an overall length of 43.3 inches. Weight was 12.5 lbs.
It was a long, heavy rifle chambered for a cartridge only readily available in Switzerland. Although the Swiss did not normally expect large export sales of military weapons, they were willing to use excess production for exports if the chance arose. As a result, an export version of the 510-1, designated the 510-4, was chambered in 7.62x51mm NATO and was shortened and lightened. The resulting rifle is much handier than the 510-1/Stgw 57. Still, only limited export sales resulted, primarily to Chile and Bolivia.
Beginning in 1969, semi-auto versions of the 510-1 and 510-4 were imported into the USA. The 510-1/Stgw 57 semi was designated the PE-57 and the 510-4 was designated the AMT (American Match Target). Although a small number of SIG 510-4s were imported legally into the USA with select-fire receivers but semi-auto internal parts, SIG quickly produced a rifle built as a semi-auto. These rifles were designed to be more "politically correct" by removing the bayonet lug and grenade rings around the barrel. This was the version named the AMT. Importers during the period from 1969 to 1978 included: Benet Arms, SARCO, Osborne Brothers, Mandall, Golden State Arms, and SIGARMS. The figure generally accepted for the number of AMTs imported during this period is 1,440. Additional AMTs were sold from 1979-1989, reportedly as parts guns. It is my understanding that many or all of these used parts kits from South American 5104s--Chilean FAMAE, to the best of the author's knowledge--and will have the bayonet lug, grenade rings, and military flash hider. It is also possible that some parts were imported from Switzerland and assembled on U.S. receivers. Estimates are that total AMTs in the USA combining the original imports and the parts guns is around 3,000.
It is not surprising that the number of AMTs sold was low, as it was always an expensive rifle. Retail price in 1978 was $1,700, equivalent to about $6,375 in 2017 dollars. Still, that would actually be a bargain price for an as-new AMT today, as they are highly sought by SIG aficionados. Another factor that influenced at least one of my friends not to purchase an AMT when they were originally imported was the difficulty in obtaining magazines. 510-4/AMT
The Stgw 57 was the Swiss battle rifle in 7.5x55mm upon which the AMT was based. The sealed tin with the rifle holds 24 rounds and was issued to reservists in case they had to fight their way to their rally point. 20-round box magazines have always been scarce, much more so than the 24-round box curved magazines of the 510-1/Stgw 57. This is reflected in the price of magazines. For comparison, a PE-57 magazine will currently sell for around $100, while an AMT one will sell for what the market will bear, but $400-$500 is a fairly common price. Since the mag well is basically the same on an AMT and an Stgw 57/PE-57, the less expensive 24-round magazines may be used, though they are de signed for the 7.5x55mm cartridge. In my experience, the PE-57 magazines will normally function reliably in the AMT with little or no alteration (if they are the older version with metal, rather than plastic followers), though using the magazine designed for the rifle is certainly preferred.
As is to be expected with a Swiss-made rifle, fit, finish, and overall quality of the AMT are excellent. Most shooters have never seen an AMT but are immediately impressed when they do. Because of the quality, most find it hard to believe that it was a production military rifle.
Swiss military rifles were built with the assumption that a lot of rounds would be fired through them during the regular match shooting that was part of Swiss Reserve training. As a result, one interesting feature of the AMT action is that the recesses into which the locking rollers fit are self-contained parts held on by Circlips. When these recesses become worn, the Circlips may be removed and the worn part replaced with a new locking recess module. Thousands of rounds can be fired between replacements of the locking-recess module.
Swiss rifles are known for their quality barrels, and the AMT is no exception. The barrel has four-groove rifling with a 1:12 twist to optimize that 7.62x51mm NATO cartridge. A perforated aluminum barrel shroud extends within nine inches of the muzzle to protect the barrel and act as a heat shield. The flash suppressor is of birdcage type. Attached to the barrel shroud is the bipod, which folds along the top of the rifle but rotates into position for shooting. Unlike some rifle bipods, this one stays out of the way unless needed.
Among other especially noteworthy features of the AMT are its cocking handle and winter trigger. The cocking handle is often described as shaped like a beer keg, and that's a good description. It is aesthetically pleasing but is also very practical, allowing a firm grasp to pull back the bolt, even when wearing winter gloves. The beer keg is non-reciprocating. And, speaking of winter gloves, a foldable winter trigger allows firing the rifle with gloved or mittened hands. Remember, the original 510 was designed for troops who might see combat in the Alps. The winter trigger may also be used for precise long-range shots, as the extra leverage makes for a better trigger pull.
The AMT is equipped with a folding carry handle of the type familiar on the FN FAL. ft is located at the front of the receiver, positioned well for the rifle to balance when carried by the handle. There are often critics of carry handles, the usual wisdom being that rifles should be carried ready for action or slung. Remember again that the AMT was designed for troops who would likely fight in the Alps on uneven ground that might require uphill climbs. Whether it was intentional, and being a Swiss rifle it probably was, the barrel is canted slightly upwards when using the carry handle. This would lessen the possibility of the muzzle digging into the earth during a steep uphill climb.
The rear peep sight is better than on many battle rifles. It is adjustable between 100 and 600 meters and is regulated for the 7.62x51mm NATO round. If elevation or windage is off, adjustments may be made to the front sight using a hex wrench.
Once again, as is typical of Swiss rifles, the AMT is designed for shooters. The pistol grip is comfortable, as is the butt stock, which allows a comfortable cheek weld. Magazines are inserted by rocking them in or out, as with an FN FAL. When shooting prone using the bipod, a magazine change may be carried out by turning the rifle on the bipod without lifting it from the ground. The paddle magazine release is easily operated but is shielded by the trigger guard from inadvertent operations. The selector/safety is not designed to be operated by the thumb of the shooting hand unless one has fingers as long as Nosferatu. I've only fired the semi-auto version of the 510-4/ AMT but have fired a select fire Stgw 57 and found this to be the case on that version as well. Use of the support hand to operate the safety is necessary.
The comfortable forearm and AMT's balance make it one of the better battle rifles for firing offhand. It also allows use of an improvised rest. But, for accuracy, it is better to use the bipod. As mentioned earlier, the AMT uses a roller-delayed blowback action; however, to me, at least, the movement of this action is not as noticeable as with the HK91/G3.
In shooting the AMT for this article, a friend and I used highly accurate Black Hills 168-grain match ammunition to test the rifle's accuracy. With this ammo, five-shot groups were fired at 100 and 200 yards off of a standing rest, or prone using the bipod. The best groups were around 1.5-1.75 MOA: 1.5 inches at 100 yards and 3.5 inches at 200 yards. Trigger pull using the standard trigger was good, but not great. The winter trigger was not used for shooting these groups. I did use it at 300 yards on hanging plates to familiarize myself with it. It did, indeed, allow what seemed to be a lighter trigger pull due to the additional leverage. Note that the winter trigger folds tightly against the receiver when not in use, placing it well out of the way. The AMT was completely reli able with about 100 rounds fired by two shooters. AMT 20-round magazines aid reliability, as they have a built-in feed ramp.
SIG AMT experts note that accuracy is improved using the special SIG/Wohler scope mount and the Dr. Wohler 4X scope on the AMT. Some Swiss shooters also use the Kern 4x17 scope. The problem is that prices for a Dr. Wohler scope and mount can run as high as $10,000 or more (that is not a typo!). By the way, note that there are Dr. Wohler 4x17 scopes that were made for the Carl Gustaf recoilless rifle. I understand there are differences in their optics from those for the AMT. The version for the AMT also was designed for the special AMT mount. According to Swiss rifle experts, only 100 of the AMT Dr. Wohler scopes were ever made, hence their rarity and expense.
On sites devoted to Swiss rifles, some posters have referred to the AMT as a "work of art. " It is an example of Swiss craftsmanship, much as is a Rolex watch. However, like a Rolex, the AMT is designed to function well even in harsh conditions and to perform its job accurately and effectively. It does that. Despite the fact that an AMT today is a very expensive rifle, most are not safe queens. Owners like to shoot them.
As I finished this article, my AMT was leaning against the safe, ready to be put back in storage. But after handling it while writing this article, I just put it in a case and got out 60 rounds of match ammunition to take it to the range another time before putting it away. It's just that great a rifle!
SIG AMT SPECIFICATIONS
Action: Roller-Delayed Blowback
Overall Length: 40 inches
Barrel Length: 20 inches (1/12" twist)
Weight: 10 lbs., 1 oz.
Magazine 20 rounds (5- and 10-round
Capacity: magazines available)
Sights: Peep Rear adj. between 100 and 600 meters, post front
Caption: Right-side view of the AMT, offering a good view of the contrast between the nicely finished wood, the blued receiver and barrel, and aluminum "beer keg" cocking handle.
Caption: Left-side view of the AMT, showing the selector, carry handle, and the Swississue sling.
Caption: Here we see both the SIG-AMT and SIG STG-57 semi-auto rifles as shown in the 1982 edition of G uns & Ammo Annual. The high prices of these two rifles would keep both in "dream gun" status to many para-military firearms aficinados including Firearms News Editor Vincent DeNiro who has wanted one since the early 1980s when he was in high school.
Caption: The AMT's forearm is comfortable for grasping and also works well when firing from an improvised rest; it and the butt are of nicely finished wood.
Caption: The safety/selector switch is not convenient for operations with the thumb of the shooting hand, so is best manipulated with the support hand. Note the magazine release paddle just in front of the trigger guard. Note also the carry handle.
Caption: One of the most distinctive features of the AMT is its beer keg cocking handle; just ahead of the cocking handle is the Circlip that allows worn locking recesses to be changed.
Caption: AMT's peep sight, which is adjustable between 100 and 600 meters. It allows precise shooting with practice and with care in aligning with the front post.
Caption: Alternate view of the peep sight showing the clear elevation markings.
Caption: The AMT's carry handle is designed to balance the rifle well for carrying; note that the muzzle is pointed slightly upward, probably to keep it clear of the ground when climbing uphill.
Caption: The built-in feed ramp of the AMT's magazine is an aid to reliability.
Caption: AMT's winter trigger folded down for use; it also allows an easier trigger pull for longer-range precision shooting.
100-yard five-shot 1.5" group fired from the AMT using Black Hills 168-grain Match ammo.
Caption: AMT manual and parts diagram.