What are these primers trying to tell me?


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duck911
November 8, 2009, 12:51 PM
Hi all,

I went to the range yesterday to sight in my new (to me) .17 Fireball.

To keep from paying $25 for a box of 20 rounds, I just loaded up a small 20-round batch of ammo at Ramshot's starting load:

Brand new 17 FB brass
Winchester Small Rifle primer
18.6 gr TAC
20 gr Hornady v-max

This is the minimum load listed for this powder.

Upon firing, my primers looked cratered. There were no other signs of pressure, no tough bolt lift, nothing else out of the ordinary.

I have a real hard time believing I have pressure issues at this powder charge (though I guess anything is possible). But, I have nothing else to compare these spent cases to, either.

Do you all think the more likely culprit is a slightly large firing pin hole and I am getting a little flow back into it?

If so, is it anything to even worry about?

thanks,

--Duck911

http://home.comcast.net/~duck911/primer1.jpg
http://home.comcast.net/~duck911/primer2.jpg

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NCsmitty
November 8, 2009, 01:12 PM
They do appear to be cratered, but do not look over pressured. The load is actually lower than Ramshot has listed as a starting load at their site(20gr).

Are you sure your primers aren't small pistol by mistake?

Oversize firing pin hole in the bolt face?



NCsmitty

The Bushmaster
November 8, 2009, 01:14 PM
Increase the powder charge and try again. If you have no other signs of over pressure (Primers are a poor indication) you are experiencing low pressure in that the case isn't gripping the chamber wall and is being SLAMMED against the bolt face. Or the firing pin port is over sized.

Walkalong
November 8, 2009, 01:40 PM
No pressure to speak of. The edges of the primers are still nice and round. As The Bushmaster and NCsmitty posted, the little bit of cratering around the firing pin is more likely poor fit than over pressure.

duck911
November 8, 2009, 01:47 PM
Nope, they're rifle primers for sure (I don't have any pistol primers that are Winchester) Also, I think you're looking at the data for the .17 Remington, not the fireball. The fireball's starting load is 18.6 with the 20 gr v-max, not 20. So, I am not underloaded, at least according to the book. But, point taken and Bushmaster is eluding to it too, that maybe I just need to continue to carefully work up the load.

I may also try some different primers and/or some factory rounds to see what happens.

thanks guys,

--DUck911

rcmodel
November 8, 2009, 01:49 PM
Like everyone said, too low a pressure for them to come back and flatten out against the breach-face.

The part around the hole is extruding into the hole, but the rest of the primer is not backing out enough to level it out. They are still setting below flush where they were seated.

BTW: What are you shooting them in?

rc

Canuck-IL
November 8, 2009, 01:50 PM
Change brands and try it at that load ... ever since Win stopped production of the siler colored (nickel plated?) primers, there have been numerous reports of soft primer issues ... get some Rem 7 1/2s or CCI.
/Bryan

NCsmitty
November 8, 2009, 04:13 PM
I think you're looking at the data for the .17 Remington, not the fireball.

Sorry about the misinformation, duck911, your exactly right. I try to avoid those mental errors.

I would up your load another .5gr and try, then inspect for any changes. If you still have the problem with the primers, change to another brand if possible, as Canuck-IL mentioned.

How did the 17 Fireball group with the original loads that gave case problems?


NCsmitty

duck911
November 8, 2009, 04:32 PM
Thanks again for the feedback, guys.

NCsmitty, I only shot 8 shots - first 3 were to sight in the rifle. The last 5 ended up in a ~.7 inch group.

Not too bad for a load I just tossed together to sight in the rifle!

--Duck911

proplinker
November 12, 2009, 12:14 AM
Read The Bushmasters post agian, and reload a little hotter

SSN Vet
November 12, 2009, 12:25 PM
What are these primers trying to tell me?

Let's do it again! :)

fireman 9731
November 12, 2009, 04:01 PM
My vote is for soft Winchester primers...

Kernel
November 13, 2009, 01:39 AM
you are experiencing low pressure in that the case isn't gripping the chamber wall and is being SLAMMED against the bolt face
+1

It's not HIGH pressure. It's due to LOW pressure. This same issue perplexed me, in the pre internet days, when I first started loading for the .30-30.

snuffy
November 13, 2009, 02:15 AM
Increase the powder charge and try again. If you have no other signs of over pressure (Primers are a poor indication)

I'll go one further, "primers are NO indicator of pressure". Reading primers is like reading palms to tell the future. They're not reliable in the least. As said, low pressure!

twice barrel
November 13, 2009, 08:53 AM
"I'll go one further, "primers are NO indicator of pressure". Reading primers is like reading palms to tell the future. They're not reliable in the least."

Who told you that? :D

The OP recognized something was amiss and checked around. If he'd been approaching high pressure he'd likely have flattened primers and a very narrow groove around the cup instead of one that wouldn't appear to have been fired were it not for the pin indentation. Like the others I vote worn boltface/pin, soft primer, low pressure or a combination thereof.

But I sure as heck think the primer is a good thing to examine as I'm developing a load and recall most load manuals direct one to do so.

Is it definitive? Not necessarily. A hard primer may not reveal much until you can't lift the bolt on a bolt action. But then you should have noted the unusually shallow strike as you were working you load up.

The observation just struck me as odd.

Regards,

TB

kelbro
November 13, 2009, 10:37 AM
Were the necks also 'sooty'? If so, definitely too low pressure.

Is your chamber clean and free of oil?

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