Traditional lead pellets for airguns come in four basic calibres: .177, 20, .22 and .25, and in a wide assortment of weights, styles and shapes. But modern trends have seen the development of composite pellets which are lighter, faster and harder hitting.
In recent years airgun pellets have undergone a remarkable transformation becoming space-age missiles that are much more effective for hunting small game and varmints. The first unleaded pellet was the Prometheus, which is still available and consists of a straight-sided - in .177 calibre - synthetic skirt mated to a bullet-shaped head made of zinc alloy. They were also made with truncated heads in .177 calibre for those who preferred a semi- flat configuration. Because of their very light weight, Prometheus pellets develop much higher muzzle velocities than regular lead pellets of the same calibre. Coupled with the hard zinc alloy and head shape this makes them capable of penetrating more deeply at short to moderate distances.
The discontinued Titan Black utilized a similar design, except it was heavier than the Prometheus and performed better at longer ranges because it retained its velocity better and drifted less in wind. It was probably the better ballistic qualities of the Titan Black that influenced Prometheus to bring out a new composite design called the Paragon. The Paragon Z1, the most popular of the three versions offered, features a dome-shaped zinc alloy head married to a synthetic body and an average weight of 11.5gn. The Paragon turned up much higher velocities than conventional leaden pellets of the same calibre.
Paragon’s Z1 and C1 pellets have bullet-shaped heads, with the Z1 made of zinc and the C1 of copper. Their weights vary considerably, with the .22-calibre Z1 at 15.5 gn, and C1 at 17.5gn. The latest Z2 .22-calibre pellets have a bright green body, a flattened zinc head and weigh 11.7 grains.
It was inevitable that the big Spanish airgun manufacturer, Gamo, would get into the act. Their Gamo Rocket in .22-calibre is a heavy pellet weighing 14gn. A skirted design it has a copper ball within a antimony/lead alloy body. Gamo also introduced a lead-free, ultra-light 4.9-grain Raptor Power Pellet in .177 made entirely of “ballistic alloy” (most likely zinc) with 18 Karat gold plating which is claimed to eliminate barrel corrosion, and increase velocity and accuracy by 25-percent. I haven’t seen any in .22 calibre but the .177 pellets go hypersonic at over 1500fps!