LETTER OF THE MONTH
Checking breech pressures
Q I have only been reloading ammunition for my .270 Winchester for a short time and have kept my loads mild, but now I would like to gain higher velocities. I know I will have to increase the powder charges, but how do I tell when pressures are getting too high?
Alan Anderson
A To gauge pressure levels A without instrumentation, look at the cartridge case. It won’t tell you how much pressure the load generates, but it can show you when you’re getting above or below reasonable levels.
Stiff extraction or shiny ejector marks on the case head give indications of high pressure. An extruded primer may or may not; a large channel around the firing pin hole in the bolt can also cause a primer to extrude. A badly flattened primer is a more reliable red signal.
Head expansion is the most reliable indicator and I recommend you invest in a micrometer or a dial caliper. Measured with a micrometer, head expansion of more than .001” (.025mm) is a warning to reduce your load.
Marbles peep sight
Q I recently bought a secondhand Winchester 94 Angle Eject which has a Marbles aperture sight attached to the tang. The gun shop where I bought it told me to mount a scope for more accurate shooting. I’d like to give the peep sight a go but don’t know how to use it. Can you give me a rundown on how it
