RWS Primers

Of all the reloading components, it is probably the primer that gets the least attention. Most gun shops stock CCI and Federal brands, and occasionally Remington, and we tend to buy whichever they have on the shelf. Recently however, some primers from RWS found their way onto my reloading bench, in both large rifle and small pistol; so, time to give them a try.

Size and shape

All large rifle primers are 0.210-inches in diameter and small pistol primers 0.175-inches and, although checking the dimensions of such small components isn’t easy without specialist equipment, it was possible to establish that the RWS primers are very consistent in both shape and size.

Testing primers in isolation isn’t easy, as all they contribute to the completed ammunition is a spark but testing for sensitivity was possible using a Taurus long barrelled revolver. These guns have an adjustable hammer tension, so it is possible to change the force with which the hammer strikes the firing pin. The RWS primers continued to ignite, even when the spring was at its lowest setting, so sensitivity is certainly very good, and they would therefore perform well in the most finely tuned of guns. Testing, testing!

For testing in terms of consistency, the RWS primers were substituted into an already proven 45-70 load and fired through a chronograph. The results were remarkably consistent, with the velocities of over a five-shot string varying by no more than 6 FPS (The printout from the chronograph was witnessed and retained). The chosen load has always performed well; however, the substitution of RWS primers did show an improvement in terms of consistency of velocity.

All the fired primers showed a ‘normal’ firing pin indent and there was no piercing or deformation visible on the primer face.

Although testing wasn’t extensive, these primers certainly seem to offer some clear advantages, in terms of both sensitivity and consistency, and they are worth giving a try, to see if you can squeeze that little bit more out of your own reloads.

Many thanks to Cheshire Gun Room in Stockport for sourcing the primers tested.