This rifle is said to have been developed in response to the Munich Massacre at the 1972 Summer Olympics. The West German police units could not engage the terrorists accurately and precisely enough to prevent them from killing the hostages. Heckler & Koch was then commissioned to create a high accuracy, large shot capacity, semi-automatic rifle for police and military use. The result has a long and outstanding reputation as an extremely reliable and high performance rifle; commonly associated with elite sniper units to which a standard was set for almost all sniper rifles to measure up against - even today.
Due to its high cost ($12,000 to $15,000 USD per rifle) and government import restriction, the number of PSG-1 in the United States is as of 2005 at fewer than 400, mostly in the hands of wealthy private collectors. Consequently, contrary to popular belief, only a very few law American enforcement agencies make use of the PSG-1.
The PSG-1 is mechanically based on the G3 rifle and features a low-noise bolt closing device (similar to the forward assist on the M16 series rifles) to allow the shooter to remain silent until a shot is fired. Its expected accuracy is below 1 minute of angle (MOA) and it is considered to be one of the most accurate semi-automatic sniper rifles, capable of putting 50 consecutively fired rounds of match ammunition inside an 80 mm circle at 300 meters (3.14 inches at 328 yards).
All PSG-1s are free of iron sights but come mounted with the Hensoldt 6×42 scope with illuminated reticle, a heavy free-floating barrel and adjustable stock. The PSG-1 stock is of high impact plastic, matte black in color, and can be adjusted to better fit anybody using it. It is adjustable for length through a pivoting butt cap and includes a vertically-adjustable cheekpiece. The PSG-1 comes without iron sights because the adjustable cheekpiece of the stock places the shooter's head too high to use iron sights. The forend of the PSG-1 is fitted with a T-way rail for sling swivel or tripod. The PSG-1's official suppressor is manufactured by Brügger & Thomet.
The rifle also features a removable and adjustable trigger unit, for further individual fitting of the rifle. The trigger is adjustable for pull and is removable from pistol grip. The pistol grip is of a target-type with an adjustable palm shelf.
Another unique characteristic of the PSG-1 is, after firing, the bullet casing is ejected with substantial force, reportedly enough to throw it approximately 10 metres sideways (the SVD also has a similar tendency). While this is generally not an issue for law enforcement snipers (as law enforcement snipers generally don't have to face enemy counter-snipers), it greatly compromises the military use of the rifle, because it would easily give away the sniper's position. The brass is also difficult to find for clearing the area of usage marks afterwards, due to the wide area in which it could have landed. Not only does the PSG-1 eject brass some distance, but it also crimps the casing severely, meaning most casings cannot be reused.
The PSG-1A1 was released by Heckler & Koch in 2006, and features two major changes. First, the charging handle was relocated a couple degrees counter-clockwise. This was due to the fact that when locked rearward, it often physically interfered with the long scopes commonly used on sniper rifles. The second change is the replacement of the Hensoldt 6x42 scope. Non-police users have found the scope's 600 meter range adjustment limitation, 6X magnification, and simple crosshairs inadequate for their needs. In addition, the rechargeable batteries are difficult to recharge, and to find replacements for. A final fault is that Hensoldt (military wing of Zeiss) does not repair this scope in the United States. For these reasons, the PSG-1A1 has been outfitted with a Schmidt & Bender 3-12x50 Police Marksman II scope, mounted on 34 mm rings.
However, despite Heckler and Koch's intention that the PSG-1 is meant for military and law enforcement, it is somewhat too delicate for rough use - typical of military service and was far too heavy for a standard calibre rifle weighing in at 8.1 kilograms. Instead Heckler & Koch came up with a militarized version of the rifle now known as the MSG-90.
According to some rumors, PSG-1 is one of the most accurate semi-automatic sniper rifles available. If not, the most accurate semi-automatic sniper rifle. Many people claim the PSG-1 is capable of putting 50 rounds into a baseball sized target at 300 meters (this roughly equates to 1 MOA). Many sniper rifles today are capable of repeatedly shooting 10 rounds to 1 MOA, but if the rifle is said to be able to repeatedly shoot 50 rounds and can still maintain 1 MOA is already a cause for suspicion. Furthermore, Heckler & Koch does not have a 300 meter indoor range. If the test is conducted outdoors, even a mild wind can disrupt the test.
In 1982, the US Army tested the PSG-1 along with several American made sniper rifles. During the test, the PSG-1 yielded worse accuracy than the M21 and the M40A1. However, the ammo used during the test is the US military's M118 cartridge, and it is said that Heckler & Koch's firearms are quite sensitive to the kind of round used, and if they are not loaded with German made rounds, their accuracy may degrade. Some people who have purchased the H&K SL8 reported their rifles showed poor accuracy. However, when they switched to German made rounds, they reported improved accuracy.
In the US, those who purchased the PSG-1 complained the rifle showed poor accuracy. Experienced shooters will tell them up to 85% of the PSG-1's and MSG-90's accuracy depends on the kind of round used. Heckler & Koch recommends that only the products recommended in the owner's maual should be used with the PSG-1. In short, the PSG-1 performed poorly during many target competitions in the US. The PSG-1 performs best with European made powder, such as those made by RUAG or Dyno Nobel.