Pierced primers Rhineland 45 acp conversion

[Webley No.5]

Well I’ve run out of ideas. I have assembled a Rhineland arms 45 acp conversion on a No4 mk1 action. I cannot get it to stop piercing primers. I’ve shot commercial Remington 230gr, Winchester 230gr, I’ve tried a couple reloads at starting load and max load. All consistently pierce primers. The pierce is a pinhole roughly center in the dent left by the firing pin. I can post pictures later today. Anyway I’ve confirmed headspace as between 0.900in and 0.910in, does not close on a 0.920in no go gauge. I checked firing pin protrusion, was originally 0.045in, I then polished the tip starting with 400grit and finishing with 1000grit. After that reshaping protrusion was 0.042in and I couldn’t see any sharp edges under 4x. Tested and same exact thing. Also should note I have never had a failure to fire. To my knowledge Lee enfield pin protrusion should be 0.040-0.055in so I’m no the low side. I’ve heard of weak firing pin springs causing pierces, so I made a 0.160in spacer to preload the spring (fyi this is the max you can add and still be able to #### the rifle). No change, so either the spring is extremely weak or not the issue (this is a low pressure cartridge and this system is made to handle 303). So I don’t think that’s the case. I then unscrewed the firing pin one rotation as this will decreased pin travel and spring force slightly, checked it only protruded when in the fired position, tested, no change. Then because I was out of ideas I sanded the pin stop on the firing pin to increase protrusion to 0.050in, that also made no change.
So at this point the only idea I have left is to decrease protrusion to below 0.040in and see if it stops piercing before I start getting failure to fires.
Any better ideas?

 

[tiriaq]

How well does the tip of the firing pin fit the hole in the face of the bolt head?

 

[Webley No.5]

Seems to fit quite well when full protruding. Nice and tight. I’ve had a Just right carbine in 45acp that had more space and would show some primer flow into the space on +p loads but no signs of that on this

 

[guntech]

... and you are using rifle primers not pistol primers???

 

[Webley No.5]

Problem solved. Rather than polishing the tip with sandpaper I reshaped it a bit with a whetstone and I got it to stop piercing. For those that care my method that worked is as follows. I dipped the tip in machinist blue, put the pin in the lathe used a whetstone to flatten the tip until I had a spot about half the outside diameter of the tip flattened. I then re-dipped pin in blue and rounded the tip so as to leave a bit of blue in the center and hence some small plateau to the pin. And that seemed to work. Weird I’ve shaped a few pins for Mausers before and never had this issue. But the blue and whetstone was a nice was to get a snap and see what I was doing. Thanks for everyone attempting to help. Also everything tested was pistol primers.