Ejection issue

F

Freebore1

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Being new here I was directed over to this leg of the forum for possible issue feedback or recommendations.

I recently rebarreled a BLR81 (lever action Browning) with a Krieger barrel 21" in 7mm-08. My issue is that Norma, Rem, W-W brass is very hard to eject with loadings of 46gr of H4350 w/145 Speer sptz. velocity is 2675fps. This loading shows slight pressure (primers somewhat flat but I've seen flatter and no issues.)

Now when I went to some nickel plated Fed brass I have NO ejection issues even at 47 grains. Primers are not flattened. Velocity is 2750fps.

The chamber was originally finished w/320. Thinking it was bolt thrust we re-polished to 220 grit. No change, unplated brass still 'sticks'.

Your thoughts on what could be the difference on brass. My 'smith said 'good thing you had some nickeled brass on hand'
 
I'm confused.....

Sounds to me like you've got EXTRACTION issues, not ejection problems. Ejection is the act of throwing the case clear of the rifle.

It also sounds as if your load is simply too hot. back down the load 100fps and see if the problem goes away. If it does not then get back to us.

IMO the "problem" lies in the necessarily small barrel tenon of the lever action rifle coupled with receiver flex. You're experiencing action/chamber flexure before seeing more common signs like flattened primer.

Of course I could be wrong, back the load off and see what happens.

al
 
1. Back off your load.

2. You've got two extremes when you switch brass. What does this tell you?

Nickel is harder than brass. It has a higher "lubricity" to it. While brass has similar qualities, it's not as good as nickel. So, if your running borderline with pressure it's reasonable/expected to think that nickel brass will still cycle where's brass is fussy.

Thinking bolt thrust is good, but what was/is the surface finish on a plain brass case after firing? Is it frosted up at all? If it is, then your chamber is a bit rough and I'd buff it out a bit. If the brass looks ok or has a light frost that you can live with (this is how I do my personal guns) then I'd leave it as it's biting the chamber as much as its ever going to. I like this because it mitigates bolt thrust and brass flowing towards the neck. I want my cases to stay put as much as possible.

A flat primer is not the end all in diagnosing pressure either. It's only one of a few symptoms. If you have ANY you should back off your powder charges and reassess. Throat lengths/angles, bore dimensions, and bullet types/weights will all influence pressure signs just like powder charges.

Hope this helped.

C
 
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