Browning 71 primer strike...is this normal?

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thepitchedlink

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OK, this is my first experience with the M71. There are new brass, IMR 4895, 50-54 gr with 200gr Hornadys. Is this what fired cases always look like coming out of a M71? The pics of the single case shows that there is a pin hole right beside the primer....I did not notice anything when I fired it..only when I looked at the cases. It was with the lightest load. Any ideas?




thanks Pitched
 
Can you give photos of the bolt face? That most definitely in NOT normal...........the ruptured primer is a Win ammo problem and has nothing to do with your rifle, but raised ridge is alarming to me, neither of my originals do this to primers.
 
Try backing off your powder a couple grains and see what happens. I don't think headspace is an issue but your primers are flattened, brass is swaged into ejector recess, there are bright marks on the case head and the primer lead are all signs of excess pressure. Your rifle may not like 50grs of IMR 4895. (55gr IMR 4895 is max from my data).
 
Your loads are too hot to start ... "Multi-faced" bolt faces can make weird primer strikes but reduce your load to start with...
 
guntech said:
Your loads are too hot to start ... "Multi-faced" bolt faces can make weird primer strikes but reduce your load to start with...
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This. Your load is hot, this not normal on a 71. On an original 86 it is common to see a raise on the primer due to the ejector design the 71 uses a different ejector for higher pressure use that does not go to the edge of the firing pin.
 
Doesn't matter what the data says that load is way to hot, 348 brass also separates above the rim quite quickly with hot loads. The gas came past the primer, the primer is flattened and flowed into the ejector recess that is excess pressure.
 
My data shows 44 to 53 grns of H4895. IMR is a hotter powder. My load notes show 48 grns of IMR 4895 caused case separation on third loading. I had best case life and accuracy with several 71's with a near max load of 65 grns H4831 at 2380 with a 200 Hornady. Never had luck getting advertised velocities with IMR 4895 or 4320 without short case life.
 
thepitchedlink said:
OK guys thanks, I'll back off the grains and try another powder or 2
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I have a Winchester model 71 deluxe and with the 200gr Hornady and near max loads using either IMR 4320 or IMR 4350, no problems or signs of preasure. And using, again near max loads, with IMR 4064 with the Barnes 220gr Originals and the Barnes 250gr Originals, good accuracy and no signs of excessive preasure.



 
Ya know, it's funny....I look back now at this thread and feel dumb...I look at my own pictures and all I see are classic over pressure signs. At the time, I didn't see them.....I really was convinced there was something amiss with the gun it's self. I didn't even really understand that I was dealing with a multi piece bolt face until I sat there tonight and actually looked at the damn thing. I think the other thing that fooled me was that the chorony was reading perfectly....The only other time I've had a gun show excessive pressure with starting loads, the speed was there as well. This time, the speeds where right where the book said they should be....the speed even increased at a normal rate, about 80 fps/grain.....stupid gun even grouped better as the charge increased!!! This one really fooled me, so thanks the all of you that answered this post and woke me up....It'll be a while before I forget this go around.
 
thepitchedlink said:
Ya know, it's funny....I look back now at this thread and feel dumb...I look at my own pictures and all I see are classic over pressure signs.
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Don't feel dumb, we all have our moments! LOL

I have run some pretty hot loads through my 71 and had some decent half moon marks on the primers but nothing like what you show. They weren't hard to extract at all?
 
Bolt face on an original Winchester 71. Your not going to get that line across the primer with this one
SAM_3232_zps6eb7a55a.jpg


Bolt face on the Browning.
SAM_3231_zpsf2f8806e.jpg
 
The pierced primer (I bet it's W-W WLR!) is typical of a bad material failure (hardspot). Because you have the "pressure signs" I really doubt it would go through a warranty process, though.
 
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