gun fed from two 45-round quadrant-shaped pan magazines (each magazine had a place for nine 5-round stripper clips). Helical Helical magazines extend the drum magazine design so that rounds follow a spiral path around an auger-shaped rotating follower or drive member, allowing for large ammunition capacity in a relatively compact package (compared to a regular box magazine of similar capacity). Early helical magazine designs include that patented by an unidentified inventor through the patent agent William Edward Newton in 1857 and the internal magazine of the Evans Repeating Rifle, patented in the late 1860s. This type of magazine is used by the Calico M960, PP-19 Bizon, CS/LS06 and KBP PP90M1. The North Korean military uses a 100- to 150- round helical magazine in the Type 88 assault rifle. Helical magazines offer substantially more ammunition carriage, however they are inherently complex designs. As such, they can be difficult to load and may decrease the reliability of feeding the weapon. STANAG magazine A STANAG magazine or NATO magazine is a type of detachable magazine proposed by NATO in October 1980. Shortly after NATO's acceptance of the 5.56×45mm NATO rifle cartridge, Draft Standardization Agreement (STANAG) 4179 was proposed in order to allow NATO members to easily share rifle ammunition and magazines down to the individual soldier level. The U.S. M16 rifle magazine was proposed for standardization. Many NATO members subsequently developed or purchased rifles with the ability to accept this type of magazine. However, the standard was never ratified and remains a "Draft STANAG". The STANAG magazine concept is only an interface, dimensional, and control (magazine latch, bolt stop, etc.) requirement. Therefore, it not only allows one type of magazine to interface with various weapon systems, but also allows STANAG magazines to be made in various configurations and capacities. The standard STANAG magazines are 20, 30, and 40 round box magazines, but there are many other designs available with capacities ranging from 1 round to 60 and 100 round casket magazines, 90 round snail-drum magazines, and 100 round and 150 round double-drum magazines. High-capacity magazines In the United States, a number of states have passed laws that ban magazines which are defined as "high-capacity" by statute. High-capacity or large-capacity magazines are generally those defined by statute to be capable of holding more than 10 to 15 rounds, although the definitions vary. Other nations impose restrictions on magazine capacity as well. In Canada, magazines