Discussion Forums

mark whiteley

I would like to share some problems I have had recently with primers
I have had a 6mm dasher built for shooting varmints and fallow deer at good ranges, I hunt and don't shoot competition. for those that don't know the dasher is a wildcat br that needs to be fire formed and uses a small rifle primer. I formed 106 cases no worries and when starting load development had 4 pierced primers out of 20 shots intermittently and at different charge weights, the loads were it seemed to be average in pressure, checked by measuring the case head, the rifle is an old mauser 98 so I knew the firing pin hole would be a bit on the large side, I had installed a tubb speedlock kit and thought the spring pressure may be to much. the loads were made with 105gr bergers and 7.5 small rifle remington primers and velocity was around the 2900fps. luckily the mauser is designed with liberal gas ports in the bolt to divert the gas away from your face, the last shot pierced and moved a spring off it's position on my kepplinger trigger, a good reason to wear glasses when developing a load.


the left is pierced, middle is cci br4 primer and the loaded dasher round

I had heard long ago about this being a problem with 17 remingtons and the answer was to swap primers to cci br4's or 450's as they have a thicker cup but the remington primers are supposed to as well,
after making the change to cci br4 primers I have not had a problem, no more pierced primers. I have measured the cups on the pierced remington primers and they were obviously a mistake in the package as they are 5 thou thinner than should be.
here is where I got the info on the primers for your information
http://www.jamescalhoon.com/primers_and_pressure.php

here's a photo of the dasher


regards Mark