# Pressure Prolems in factory Ammo



## knutson24 (Feb 16, 2009)

I picked up two boxes of Federal vital shock 300 wsm 180 gr trophy bonded tips. To fire out of a model 70 coyote

used 15 round to sight in at 30 yds and then at 100 yds. After coming home and looking at the fired brass I noticed that the primers were a little cratered and a mark that looked like it was hit by a rimfire firing pin except instead of being a depression it was a ridge. all 15 round has cratered primers but only 5 rounds had the ridge :-?

Any Questions as to why this would be happening with factory ammo and what is causeing this ridge would be much appreciate. Would post pic but camera isnt high enough res to show up.

thanks,

Knutson


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## TK33 (Aug 12, 2008)

I checked my cartridges and I have found no problems.

I have had some problems with shotshells, namely fiocchi. I have asked around and the consensus from industry people is that they are producing as fast as they can and there have been some quality issues. This is just what they have said.


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## knutson24 (Feb 16, 2009)

On a side note the ammo grouped beatifully under 3/4 of an inch at 100 yards


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## Plainsman (Jul 30, 2003)

It sounds like your pressure is right at max. The short mags are maxed out and I think the SAMI specs for magnums is 65,000 cup. It's actually loaded to higher pressures than the 300 Winchester Magnum. My 300 WSM factory ammo does the same thing in a Browning Stainless Stalker.

How is extraction? My extraction is fine, so I don't worry about slight cratering.


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## southdakbearfan (Oct 11, 2004)

Cratering can also be caused by a light firing pin strike, short firing pin, and/or malformed firing pin.


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## knutson24 (Feb 16, 2009)

Plainsman said:


> How is extraction? My extraction is fine, so I don't worry about slight cratering.


Extraction is a little stiff but then again its always been a little stiff with other ammo as well. As long as I don't need to worry about damaging my rifle im sticking with this because like i said it shoot some pretty fine groups!!!



southdakbearfan said:


> Cratering can also be caused by a light firing pin strike, short firing pin, and/or malformed firing pin.


I havent had any cratering with other factory ammo or any of my reloads so i'm assuming the firing pin is fine. "Had to switch to factory loads due to the primer shortage" :-?

Thanks for the info everyone. it definately has reassured me a great deal. But im still trying to figure out what caused the ridge on the shell casing?


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## Plainsman (Jul 30, 2003)

> But im still trying to figure out what caused the ridge on the shell casing?


I guess I didn't understand that right the first time. I thought you meant the ridge around the crater. That's slightly elevated pressure, or the tolerance between firing pin and pin hole is to large.

The ridge on the edge of the case ( like a rimfire) is a pressure indicator also. It's left by your ejector. This is pressure signs one step above the primer crater. If pressure gets real high you will see a large shinny circle from your ejector.


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## knutson24 (Feb 16, 2009)

In your opinion is this acceptable or should I stop using the ammo. the ridge from the exractor was only on 5 of the 15 shots (1/3)


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## ac700wildcat (Oct 30, 2006)

I think I'd get ahold of the manufacturer and let them know about the problem. They'll probably have you send the remaining ammo back, so they can check it out. For your inconvenience, I would bet they send you quite a bit for fresh ammo than you send them. Ammo companies would rather replace the product and do a re-call on bad ammo if they have to, rather than have a lawsuit on their hands from someone getting hurt.


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## Plainsman (Jul 30, 2003)

knutson24 said:


> In your opinion is this acceptable or should I stop using the ammo. the ridge from the exractor was only on 5 of the 15 shots (1/3)


I think the mark is from your ejector on the bolt face, and not the extractor. 
Your pressure sounds border line. Most of the time you just get a shiny spot, then with more pressure you begin to see the ejector indent in the brass. If your getting a ridge check your bolt face and see if there is anything that could be causing it. Is the face of your ejector nice and flat, or does it have a machining bur on it? 
Since other ammo doesn't do it there are pressure differences in your ammo for sure, but that doesn't mean that it's not your bolt face. I would check that first and if it is nice and smooth send your ammo back as 700wildcat recommended.


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## knutson24 (Feb 16, 2009)

Plainsmen you were correct about the mark being from the ejector. I but one of the spent cases on to the bolt and the mark is exactly the same demention as the area where the ejector pushes out the bolt face.


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## Plainsman (Jul 30, 2003)

I have not looked that close at the new model 70 bolt. I notice the slot for the ejector looks a lot different. All my model 70's have the old round hole and round ejector. I didn't know they were squared off like the one in your pic. They would show a pressure sign with only modest increase of pressure.


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## knutson24 (Feb 16, 2009)

I'm not sure but i may have been experiencing the same mark on other ammo and just didnt notice it. The trophy tips are nickel coated and the coating had came off in the area and thats the only reason I had noticed.


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## Plainsman (Jul 30, 2003)

The nickel looks nice, but it often flakes like that and it can scratch your dies. I don't use nickel cases anymore. At least that's what they told me at RCBS when I spoke with them.


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## knutson24 (Feb 16, 2009)

Ya I dont use them for reloads either


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## TK33 (Aug 12, 2008)

keep us posted if you would, I am interested too see what they do.


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## knutson24 (Feb 16, 2009)

I'm sorry to say i never did send the ammo back to the factory. I ended up shooting the rest of the rounds and none of them showed any pressures signs.


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