Savage inconsistent firing pin strikes (pic)

Hildy99

Hildy99

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Just got back form shooting my newly re-barreled Savage 16 in .260. I fired 40 rounds today and noticed some firing pin strikes are normal looking and some look very light but all rounds did go off, using CCI BR2 primers. The two cases in the pic are from the exact same load (41 grains of H4350 and 140 grain Hornady BTHP) with brand new Lapua brass. You can see in the picture the primer on the left looks normal to me and then one on the right looks very light. What could be causing this? I was testing loads with more powder a couple weeks ago and saw the same thing with higher charge weights.

 
they are all seated flush with the case head. I use the Lee hand primer tool to seat primers with all my rifles and this is the only time iv'e noticed this. I'm fairly certain this is a rifle issue and not a ammo issue.
 
To me it looks like different pressures in those 2 rounds.
The left one is higher pressure, the right one low pressure.

When you fire a round, the primer is instantly pushed out of the case into to the bolt face and then the case follows (to the bolt face).
This in turn creates that flattened look with a slightly cratered pin indentation that you're seeing in the left case.
The right case seems to have stuck in the chamber without touching the bolt face.
 
legi0n said:
To me it looks like different pressures in those 2 rounds.
The left one is higher pressure, the right one low pressure.

When you fire a round, the primer is instantly pushed out of the case into to the bolt face and then the case follows (to the bolt face).
This in turn creates that flattened look with a slightly cratered pin indentation that you're seeing in the left case.
The right case seems to have stuck in the chamber without touching the bolt face.
Click to expand...

If that's happening then my load is too light to reliably expand the case to the chamber?
 
Headspace of the cases = case head clearance for that chamber. As Jerry stated virgin brass can vary in tolerances... If you had full length sized the cases the primers may have looked more uniform... Also, seat your primers below the case... seat them as deep as you can. That is how they are designed to work.
 
Headspace issue like guntech and Jerry said either it is improperly headspaced or the brass is out of spec.
Even if it was a headspace issue once the brass is formed you will be good and if you need to fl size adjust your die accordingly.
The only issue I can see at this point is the case head stretching in the web area which could eventually cause a case head separation .
You should have the headspace checked imo that way you will know where the problem is then decide what works for you, if it has a barrel nut and the headspace is to much fix it because chances are the bolthead clearance will also be affected.

If you have more unfired brass seat the bullets extra long to jamb them in the rifling with lots of neck tension so your brass forms properly.
 
Thanks guys. All my brass is fired once now so hopefully this will so away next firing. Using my Hornady Headspace gauge my fired brass measures 1.622".
 
coyote said:
If you have more unfired brass seat the bullets extra long to jamb them in the rifling with lots of neck tension so your brass forms properly.
Click to expand...

Bullets jammed in the rifling do not always hold the case against the bolt face... in most cases when the firing pin hits with over 20 pounds of force the bullet is driven into the case as the case moves forward until the shoulder stops it... for fire forming the strongest cases it is best to create a false shoulder to hold the case against the bolt face.
 
A lot of shooters have been either wildcating and forming various brass for quite a few years using this method with great success.
I'm certain that using a false shoulder is also a very good method .
 
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Maybe oil in the chamber on the well dented round,then burnt up for all the rest. Just the one comming back hard onto the bolt? Or several? Try drying the chamber well before shooting.
 
Dissasemble the bolt,and look for steel fillings in and around the firing pin,and firing pin stop shoulder.Examine closely your firing pin and its shoulder.Clean very well.Try again.Look for the problem.And in the meantime get some headspace guages,like the other gyes are saying.Make sure every single bullet you fire is the same dimension.
 
coyote said:
A lot of shooters have been either wildcating and forming various brass for quite a few years using this method with great success.
I'm certain that using a false shoulder is also a very good method .
Click to expand...

Jamming isn't reliable to obtain the strongest fire formed brass. The brass will always fire form regardless whether the brass is held hard against the bolt face or not... but if it is not held hard against the bolt face when the pressure hits, the back of the case simply stretches until the case head is stopped by the bolt face and that brass is considerably weaker than one correctly formed. A false shoulder will always do that.
 
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