In view of some shortcomings of commercially available air rifles at that time, Chongqing Construction Industry Co., Ltd. independently developed and designed a new type of air rifle using side rod compression spring, named Emei brand EM45B-1 type 4.5 mm air rifle. The barrel of the gun is fixed, so it has good shooting accuracy, good sealing performance, and is equipped with a reliable safety mechanism. After the EM45B-1 air rifle was successfully developed, the company improved on the gun and successively launched EM45B-2, EM45B-3 and lift-type semi-automatic ammunition supply air rifles, forming the EM45B popular air rifle series. . EM45B-1 4.5mm air rifle The EM45B-1 air rifle was designed and finalized in 1979 and put into mass production the following year. Because its main parts are made of high-quality steel and specially treated, they have good strength and long service life. It has been favored by the majority of airsoft enthusiasts since its launch. EM45B-2 4.5mm air rifle This gun is based on the EM45B-1 and adds a follow-up safety mechanism. The design was finalized in 1982 and was put into mass production from 1987 to 1993. The EM45B-3 4.5mm air rifle is based on the EM45B-2 and adopts a folding butt with a mixed structure of metal and wood instead of the original wooden fixed butt. This saves a lot of valuable wood and improves the overall layout of the gun. The design has been improved to make its appearance more beautiful and elegant. The gun was designed and finalized in 1987 and was put into mass production from 1988 to 1993. In addition to being sold domestically, the EM45B-2 and EM45B-3 air rifles were also exported to the United States, and the Emei brand trademark was registered in the United States. They became one of the few civilian products that earned foreign exchange at that time, bringing good economic benefits to the company. Due to its excellent quality and good economic benefits, the EM45B popular air rifle series won the third prize of the New Product Hundred Flowers Award issued by the Chongqing Municipal People's Government in 1989; in addition, the EM45B Type 2 air rifle won the third prize of the Ministerial Science and Technology Progress Award of China Ordnance Industry Corporation in 1993. award.