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Old 08-03-2019, 02:36 PM
pertnear pertnear is online now
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Join Date: Jan 2015
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Thank you for your detailed response. Here is a little background on the rifle. I originally bought the rifle at a gun show & it had already been re-barreled to a .270 Win with a fly-weight 22” Apex barrel. Other than the barrel, the butt, forend & band were all original #3. With a scope it weighed less than 7lbs! To say it had a sharp kick is an under-statement! The .270 cases from this rifle exhibited the same cratering around the firing pin indention, but no flow into the hole & no flattening. Obviously I was using LR primers.

I had a new Shilen .277 barrel stashed away so after some research I settled on getting a varmint weight contour cut on the barrel & then fitted with a standard SAAMI 6.8mm SPC II chamber. I also fitted the rifle with Ruger #1 wood & had a tuning screw installed in the hanger. Rifle now weighs 10lbs with scope & I call it a Ruger #2. My gunsmith (who I trust) says he rented headspace gauges & checked the chamber.
  • For sure I’ll expand some necks & size a secondary shoulder for a “light-crush” fit on headspace. That should yield some interesting results.
  • I did determine that indeed the off-center firing pin indent is always high at 12 o’clock. Its effect is pretty much cosmetic, but can the lifting arm be adjusted or modified to correct this?
  • The firing pin doesn’t look like much but trying to find a new one is a problem. Numrich shows firing pins & breech-blocks, but they seem to be on perpetual back-order. I thought I’d try a new firing pin first. If the breech block hole is not elongated, could a new slightly oversized firing pin be fabricated?
As a note, all Mfg’s LR primers have a cup thickness of .027”. SR primers vary by Mfg from .019” to .025” in thickness. I don’t have any info on cup hardness. I’m only experimenting with SR primers that are .025” in thickness.

Thanks to everyone for their help!

Dave
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