Author Topic: Flattened primers  (Read 679 times)

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Offline Buckman

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Flattened primers
« on: August 26, 2009, 02:17:13 PM »
I was out shooting with a friend last night and was doing pretty good at getting good groups with my handi 06.  He takes a look at my shells and says that my primers are flattened because of too much pressure.  i am shooting 51 g of W760 in a w case and using WLR primers and using a W 180g pp at COL at 3.15.  Any hints here?  I have no split cases and the handi doesn't pop open when I shoot.  appreciate the help.

Offline cwlongshot

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Re: Flattened primers
« Reply #1 on: August 26, 2009, 02:29:17 PM »
 Flattened primers are NOT a reliable sign of hi or too high pressures. they DO SHOW something is happening and may need addressing. Your best bet is to "mike" the cases.

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Offline chutesnreloads

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Re: Flattened primers
« Reply #2 on: August 26, 2009, 04:35:57 PM »
I see flattened primers with quite a few factory loads.Any other pressure signs?

Offline Graybeard

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Re: Flattened primers
« Reply #3 on: August 26, 2009, 05:41:31 PM »
The ONE and ONLY thing flattened primers tell you for sure is that.....ta da..... Your dang primers are flat. Big deal. It is the absolute least reliable indicator of pressure problems out there and in fact there really are NO RELIABLE SUCH INDICATORS.

If you're using a strictly by the book recipe and it's not listed as an absolute max load (compare in several manuals) and you aren't seating too deeply or too far out then chances are the load isn't over SAAMI pressures. However it might be. If your chrono tells you that you're getting 150-200 fps more than expected then you might be looking at pressures way higher than expected.

This stuff ain't brain surgery and it's not that precise.


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Offline wncchester

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Re: Flattened primers
« Reply #4 on: August 27, 2009, 03:30:05 AM »
Buck, you've gotten some good info. 

Try this, size a case normally and prime it.  Fire that (empty) case and examine the primer; it's likely to be proud of the head by several thousants.  If so, case stretching and the recoil face pushing the exposed primer back into the pocket while it's under normal chamber pressure is probably what's "flattening" it.  If so, that's normal and not a problem.
Common sense is an uncommon virtue

Offline iiranger

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Friend??? Re: Flattened primers
« Reply #5 on: August 27, 2009, 07:09:55 AM »
First question is "who is this guy and how does he know?" Awful lot of BS artists out there. #2). Where did you get the load? If it is in any book then you are probably plenty safe. The beginners test here, fire some factory ammo of that brand and compare primer to your reload. b). '06 dates from 1906 or did you  know that. Pressure standard in that day was approx. 45K CUP. Today many cartridges, say the .308 or .243 from the 1950s, work closer to 55K CUP. So if your '06 primers are only slightly flatter... enjoy. luck.

Offline Buckman

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Re: Flattened primers
« Reply #6 on: August 27, 2009, 07:31:14 AM »
No other pressure signs on the cases.  I will try firing an empty case with just the primer and see what happens.  The chrono was pushing these at 2650 so pressure shouldn't be a problem.  Thanks for the help.

Offline SHOOTALL

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Re: Flattened primers
« Reply #7 on: August 27, 2009, 08:56:47 AM »
nosler says your load is in the middle for a 180 gr bullet . everything i shoot in my mod 70 3006 comes out with flat primers , that said are the primers flat or have they flowed out to mesh with the case head ? I had some reloads a guy gave me that flowed and i only shot 2 . one was so hot the firing pin hole had some primer metal flow into it .
After all that how do they compare to factory loads of the same weight ? Also some primers are softer than others try some cci or winchester primers if you haven't yet . Were your primers fed. ?
If ya can see it ya can hit it !

Offline Buckman

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Re: Flattened primers
« Reply #8 on: August 27, 2009, 03:12:24 PM »
The primers are winchester and they are not so hot that they flow.
I think I will keep doing what I am doing as it works and there has been no problem with the gun or cases.

Offline torpedoman

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Re: Flattened primers
« Reply #9 on: August 27, 2009, 03:37:24 PM »
 are you sure you got all the case lube off them??
the nation that forgets it defenders will itself be forgotten

Offline Lone Star

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Re: Flattened primers
« Reply #10 on: August 28, 2009, 02:21:15 PM »
Hodgdon shows that 50.0 grains of W760 under a 180-grain bullet produces just 39,200 CUP in a pressure barrel, so it is very highly unlikely that the load is high-pressured in your Handi.  Excess headspace is the most likely cause of flattened primers at low pressures - although as stated there can be other causes.  I would not worry about it, and I would also find another "expert" to listen to in the future.  While no one knows it all, your friend thinks he knows more than he does - a potentially dangerous combination.



.

Offline huntducks

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Re: Flattened primers
« Reply #11 on: August 28, 2009, 05:41:30 PM »
Hodgdon shows that 50.0 grains of W760 under a 180-grain bullet produces just 39,200 CUP in a pressure barrel, so it is very highly unlikely that the load is high-pressured in your Handi.  Excess headspace is the most likely cause of flattened primers at low pressures - although as stated there can be other causes.  I would not worry about it, and I would also find another "expert" to listen to in the future.  While no one knows it all, your friend thinks he knows more than he does - a potentially dangerous combination.



.


i'll 2nd that. Some of my guns flatten there primers other don't seems to me that some primers cups are not as thick or hard as others, I don't think there is a true answer.



Remember it's where the first bullet goes out of a cold barrel that counts most.

Offline Dave in WV

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Re: Flattened primers
« Reply #12 on: August 29, 2009, 06:37:03 AM »
Fire a factory load and compare. My son's 760 30-06 flattens the primers with mild loads and factory ammo. The only way I can think of a mild load could cause high pressure is if the bullets were jammed into the lands before firing.
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Offline stimpylu32

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Re: Flattened primers
« Reply #13 on: August 29, 2009, 11:00:02 AM »
Buckman

I have to go with Lone Star on this one , being a Handi guy myself the first place I'd look would be headspace , my 22-250 and 25/06 gave me fits till I got a handle on it .

stimpy
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