Damaged cases

hummel

Well-Known Member
A friend of mine[honestly]:cool: has a Sako 75 in .308.I have seen him on the target and on the hill and the rifle shoots sub .75 groups with factory ammo.the interesting thing is that the rifle seems to crimp the bullet end of the fired cartridge.The crimping is not always uniform but is very noticeable:eek:There are no powder marks on the case and the primer isn`t damaged.He doesn`t home load and these are all factory rounds.I have asked a few friends who home load to have a look and none of them know what is causing it.So anyone out ther got any thoughts .The rifle is ordinary in every way.:confused:Ammo used norma 150gr bt.

Hummel
 
Hi Willie,
Sorry don`t have the knowledge to post a pic!!It looks like the rim has been tapped with a small hammer folding it in 2-3 mil,sometimes on one side sometimes on opposing sides.The estate also has a 75 sako and i1ve never seen this before.I figure it must obviously happen after bullet sent up barrel as it happens where the bullet is crimped.Some form of gas blast back??No powder marks .Not an extractor mark either.!!!
Shot thousands or rounds through many dfferent rifles and never seen this before.


Confused Hummel
 
Hummel


To be honest I'm also grasping at straws here, but:
  • has he had a gunsmith check the chamber at all?
  • Is he 100% sure it's not happening before the round is loaded? i.e. could it be something to do with the magazine?
  • If he just cycles rounds without firing, does he get the same result, or is it only when the trigger is pulled?
Yours in desperation!

willie_gunn
 
Hummel. I suspect that the case is damaged on ejection as the ejection blade is damaged/incorrectly postioned in some way. I had a Ruger 223 a long time ago and the ejection blade got bent. This resulted in non-ejection of the cases. The ejection blade needs to be examined by a competent riflesmith. Spookily I was removing fluff from the ejection blade of my Sako 75 this morning. Rgds JCS
 
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Well chaps,I will try to give you more info.As far as i know it does it with all ammo,it`s not the ejector blade,no damage before firing,no damage in the mag,you can cycle rounds with no damage but when you fire the bloody thing it distorts the cases.
As i said i`m at a loss.The owner is still happy to use it,and uses it very well!I took a case to a local gunsmith and he couldn`t say what was causing it.If i ever figure out how to post pics i will restart thread.

Cheers and thanks for your comments Hummel Feel free to come back with any more suggestions.
 
H. What happens when virgin empty cases are ejected? Have you any new brass, or fired cases from another rifle? Try cycling them. Also, can you have a close look at the bullet heads of live rounds that have been ejected. Do they show marks/scrapes? Following up on my earlier comment, it's not the ejector blade coming into contact with the case neck that causes the damage, but a poorly positioned ejector blade causing the ejection to mistime (early I suspect) and strike the inside of the action. Some photos would help. If it's not resolved, it should go back to Sako. It could be that an ejector blade from another model of Sako 75 has been installed by mistake. Sako 75s come in four different action lengths. Rgds JCS
 
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Cheers JCS,
I see what you mean,rifle is down south at hte moment but will check ejector when i next see it.

Cheers Hummel
 
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