Last week I blogged about the Extreme Polymer Research’s polymer handgun cartridges. A US company called PCP Ammunition is trying to make mostly polymer rifle cartridges. Unlike Extreme Polymer Research’s handgun cartridges, these have a steel or brass base.
The company had some cartridges on display at SHOW Show earlier this year. According to their website they will be offering polymer cased 5.56mm NATO, 6.8mm SPC, 7.62mm NATO, .338 Lapua Magnum and .50 BMG. They will sell direct to the public but their online store still has a “coming soon” sign posted on it.
There has been many attempts at polymer cased rifle cartridges. The primary problem with them is heat dissipation. Brass or steel cartridges absorb heat from the chamber before being flung out of the gun, keeping the chamber cool. Plastic on the other hand is a poor conductor of heat and will melt at a much lower temperature than metal such as brass and steel. Past attempts at polymer cased rifle ammunition has had users complaining of melted polymer residue gumming up the chamber and causing extraction problems.
[ Many thanks to George for the photo & Julio for the info ]