Law enforcement and civilian models

HK41: The HK41 is a semi-automatic version of the G3 that was marketed to law-enforcement and civilian reservists (the prefix number 4 in HK's two-digit number system technically stands for "para-military rifle"). There were two versions, one differing from the G3 by being fitted with a semiautomatic-only trigger pack, the other using a different design of trigger pack, like that of the later HK91. The first version could easily be converted to a full-automatic weapon by swapping out several parts. Limited sales at home and US import restrictions and firearms regulations led this weapon to be dropped from HK's product line quickly and it was replaced by the HK91. HK91: The HK91 is a semi-automatic version of the G3 similar to the HK41, also marketed to civilians. However, in order to comply with US firearm regulations a number of modifications to the HK91 were made that do not appear on the first pattern HK41. Internal parts that could allow fully automatic fire were removed. A shelf was welded onto the receiver where the push-pin of the trigger pack would normally go, to prevent installation of a fully automatic trigger pack. This did not allow the use of the paddle style magazine release and so the magazine release button on the right side of the magazine well must be used instead. This was considered awkward by many owners. It is otherwise identical to the G3A3/A4. Importation into the United States began in 1974 and ceased in 1989, with some 48,000 rifles being imported. A Latvian Army soldier in Iraq armed with a Swedish-made Ak 4. HK911: The HK911 was an HK91A2 with the flash hider removed and the receiver re-stamped with an extra 1 to comply with the US importation ban of 1989. The new designation theoretically made it legally immune to the Import Ban, as no "HK911" rifles were mentioned on the list of banned guns. However, the later banning of several "paramilitary" features on the HK911 made it illegal. SR9: These variants of the HK91ZF were created to comply with the Semi-Auto Import Ban of 1989, which included all variants of the HK91. They differed from the HK91 in that they had their flash hiders removed and featured a smooth forend that lacked the bipod attachment point. The SR9 series were banned from importation to the United States by President Clinton in 1997 because they could accept standard-capacity magazines. The SR9 was an HK91A2ZF with the pistol grip and buttstock replaced with a one-piece thumbhole stock. SR9 (T): The (T), or "Target", model was an HK91A2ZF with the trigger replaced with the PSG-1 model, the pistol grip replaced with an ergonomic PSG-1 grip and the buttstock replaced with an MSG90 model. SR9 (TC): The (TC), ot "Target Competition", model was an HK91A2ZF with the trigger group, pistol grip and buttstock derived from the PSG-1. G3A1: The terminology used by custom gunsmiths (e.g. Choate) and importers (e.g. Interarms) for weapons with an aftermarket side-folding stock. This is not part of official HK nomenclature. HK 51: The HK51 is not made by HK, instead being a creation of the American custom after-market. The HK 51 has no real standards but is usually a cut down and modified G3A3 or its semi-automatic clones the HK41 and HK91 and modified to take MP5 furniture and accessories. It is usually fitted with a collapsible stock; 211 mm (8.31 in) barrel; it is 589 mm (23.17 in) in length with the stock retracted and 780 mm (30.72 in) with the stock extended. PTR 91F: Additionally, JLD started manufacturing semi-automatic copies of the HK G3 called the PTR 91 in the United States. They used tooling from the FMP arms factory in Portugal to build the rifles.