Pressure Signs

johngibbs222

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Jun 15, 2012
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I have two ruger falling block rifles, a #1 in 308 and a #3 in 223 rem, I reload for both and use only Hodgdons CFE 223.
I use S&B primers large rifle and small rifle respectively and all my info is based on using these primers, they appear to be made from a fairly hard brass alloy.
All the dies are Lee and I only neck prime the cases before reloading and generally do not clean the primer pockets other than a quick twiddle with a Lee pocket cleaner. I always trim to length.
I use a Lee perfect powder measure which I have found gives consistently accurate charges of powder and measure every 5th measure with an RCBS 500/5 balance scale which I check with proof weights before each loading session.
My take on no pressure signs is as follows, when the firing pin hits the primer the whole of the flat face of the primer is slightly dished in until the pin stretches the metal causing the primer to do its job. The case comes out of the chamber easy and by looking at the primer face against the light the overall dishing is still discernible and the firing pin indentation is purely a dent with no rim pushed up around the dent and with the outer edges of the primer still exhibiting a radius where it meets the primer pocket.
My take on the first sign of excessive pressure is when the primer face is flat and the dishing I mentioned above is not visible.
My second sign is when the edges of the primer no longer display their radius ie the radius has been blown out so the primer is flat across its face.
For me the third sign is when the edges of the primer dent start to erupt outwards and can be felt, I've only seen this on a couple of loads and it was accompanied by a reverse indentation of the ejector slot that had to be "looked for".
I understand there may be more to this and these indications are only indications with no way of accurately determining the level of excess pressure.
I can't say I've experienced difficulty in either extracting or operating the gun's mechanism in the event of the pressure signs I think I may have experienced and I drop my loads to the level I used when I didn't find any indication of what I considered to be excess pressure.
Do my views strike a chord with any other reloaders out there or am I plumb wrong?
 
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kb1035

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Feb 11, 2009
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From my own experience, I have not found primer condition to be a reliable indicator of excessive pressure. I know a lot of people use it, and reloading manuals discuss it as a sign, but I've had really flattened primers on mild loads, and normal looking primers on hot loads, even within a particular manufacturer's primers from the same lot. Same thing with the raised/unraised edges around the firing pin indentation.

I don't have/shoot falling block rifles, so I can't speak to that, but in all my bolt action rifles, for me, the most telling indicator of high pressure is heavy or sticky bolt lift. When I am doing pressure tests, I know I've hit or exceeded my gun's max load when I feel a noticeable increase in the force needed to open the bolt. Sometimes it's subtle, but it's always perceivable.

I'll be interested to see what others say too.
 

MagnumManiac

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Feb 25, 2008
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I can use 3 primers in the same cases with the same loads and have 3 different primer appearances.
Another thing, even if a primer fills the primer pocket and has a radiused edge, does not mean excessive pressure.
First sign of excessive pressure almost exclusively is ejector marks, sometimes a cratered primer exhibits first, but this is a mechanical indication from the bolt, then hard bolt lift with accompanying above symptoms and then all symptoms and a locked solid bolt with a case head fused to the bolt face.
The term “Watch for flattened primers” was coined when primers were concave when made, not like today’s flat face with radiused edges.

Cheers.
 

skipglo

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From my own experience, I have not found primer condition to be a reliable indicator of excessive pressure. I know a lot of people use it, and reloading manuals discuss it as a sign, but I've had really flattened primers on mild loads, and normal looking primers on hot loads, even within a particular manufacturer's primers from the same lot. Same thing with the raised/unraised edges around the firing pin indentation.

I don't have/shoot falling block rifles, so I can't speak to that, but in all my bolt action rifles, for me, the most telling indicator of high pressure is heavy or sticky bolt lift. When I am doing pressure tests, I know I've hit or exceeded my gun's max load when I feel a noticeable increase in the force needed to open the bolt. Sometimes it's subtle, but it's always perceivable.

I'll be interested to see what others say too.
X2 although I look for the ejector signs as well, but generally bolt lift tells it all First.
 

SSgt G Cody

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I shoot bolt actions. In working up loads, I look carefully for pressure signs. I look first for primer signs, then for extractor marks, then for heavy bolt lift. If I find any of these, I immediately start backing off a step or two in my powder. I usually like speed, but Safety is ALWAYS Priority No. ONE!!! No. Two is Accuracy!
 

MagnumManiac

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How would you EVER get ejector marks on a falling block rifle? Is there even an ejector in one? I don't understand why there would be.
I was making a broad statement.
First sign of pressure in a falling block is a sticky mechanism.
Ruger No.1’s are generally very strong and will contain pressure very well.

Cheers.
 

Hard rock

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I was making a broad statement.
First sign of pressure in a falling block is a sticky mechanism.
Ruger No.1’s are generally very strong and will contain pressure very well.

Cheers.
Sounds like you are on the right track if the breech is hard too open that would definitely be a tell tell sign but still pay attention too the primers you still can pay attention too the extractor slot also if brass starts too flow it will leave a extractor indication mark also some brass is softer indicating premature pressure signs good Guaita brass will allow full potential of your load be safe and shoot straight
 

Hard rock

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Sounds like you are on the right track if the breech is hard too open that would definitely be a tell tell sign but still pay attention too the primers you still can pay attention too the extractor slot also if brass starts too flow it will leave a extractor indication mark also some brass is softer indicating premature pressure signs good Guaita brass will allow full potential of your load be safe and shoot straight
Excuse my misspelling my post should have said good brass
 

Mike Matteson

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Jun 26, 2017
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When do a load work up I watch to what the primers is doing, then ejector marks, hard opening. I stop at fatten primers. Creator of a primers to me is a sign of high pressure. I will generally see ejector marks at the same time of creator primers. I watch for all and each time I fire a round down range. It's contain watch for me. Not that I am afraid of my reloads, but I want to aware if there is a possible problem arising.
 
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