Pressure spikes
- Thread starter Cneelk
- Start date
DrMike
Ballistician
- Nov 8, 2006
- 37,402
- 6,213
Perhaps I'm going blind in my advanced years, but I don't see any smear that would concern me. Do you know if your rifle was test fired before being shipped from the factory? Did you have any other signs indicative of pressure other than what you see as shiny spots? Did you measure velocity to verify what the box claimed? Has your rifle been blueprinted to ensure that there is no excess stretch possible upon firing? Is the bolt trued? What you are identifying as shiny spots appears to be common in factory rifles. First, I would take some careful measurements of the fired cases, comparing the dimensions to factory cases to see if the chamber is on the large side of SAAMI dimensions. That would not be unusual. I would also make a series of test loads with the brass you've recovered from the first firing, neck sizing the brass, so I could discover whether these spots still appear on a second firing. Again, I don't see a serious problem showing from what you display.
- Thread starter
- #3
Well to try and answer your questions sir , I would assume the manufacturer tested it out before selling. I circled the areas and ejector marks. I will mic them out tomorrow morning, worse thing I will do is pull em dump em and start load development. Lots of humidity with freezing fog conditions. Tomorrow is a new day.
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DrMike
Ballistician
- Nov 8, 2006
- 37,402
- 6,213
Yes, in the original photo I saw what you then circled. I gave my evaluation from the photo presented. Again, I don't see that you have a problem with your rifle or with the ammunition. Best of luck to you.
- Thread starter
- #5
I see no problem with those cases. You shot the ammo, the cases expanded due to internal pressure into a tight fit in the chamber and against the the face of the bolt. That very slight scraping you see is perfectly normal. It happened when you turned the bolt handle, If pressure had been high, the primers would most likely have been noticeably flatter than they are now. I see no problem.
Paul B.
Paul B.
