Question for the gurus about pressures

Cleftwynd

Cleftwynd

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A few weeks ago I was messing around and had some H1000 to use up, some pulled Partitions and some Spitzer 140 grain of some sort, and a bunch of 7mm08 brass... so I decided to mess around with a slow powder behind the 140's in the 7mm08.

I have loaded up to 47 grains, and still have some at both 46 and 47. Odd thing is at 47 the primers just start to flatten a little but the necks are black no matter what the charge. What would cause the necks to be sooty even though I am seeing signs of pressure on the high side? 47 grains is 100% of case capacity by the way.

I have never run into this scenario before, however I have always used published data for starting loads. There is not 7mm08 data for H1000 that I am aware of. Is this soot on the necks because the powder is too slow? If so, why are the primers starting to flatten at 47 grains?

The whole purpose of loading the H1000 in the 7mm08 was just to experiment with something different for personal experience, however I am not sure how to interpret the results.
 
The powder is much too slow for the case and bullet combination.

"Odd thing is at 47 the primers just start to flatten a little-----"

Just starting to flatten the primers shows a very minimum of pressure, and as you are aware, it is lack of pressure to seal the neck, that is causing the gasses ot leak around the mouth of the case and cause the blackness.
The poor burning powder from lack of proper pressure will also make the soot balcker.
 
Thanks fellas, I will chrony these later, it was the flattened primer that was throwing me off. I will post some pics later just too add to the topic. Still fun playing with things on the bench.
 
Another individual faced with the conundrum of visible evidence that the mythical "flattened primer" is not a reliable indicator of excessive pressure.
 
I didnt actually mean excessive pressure, I had assumed that a flattened primer indicated there should be enough pressure to seal the neck in the chamber during firing. I am no English teacher, that's for sure.

I have a lot to learn, and this one was making me think too hard, so here I am.

So, from now on I will only look for cratering and flowing of my primers, lesson learned. At least this little experiment did teach me something with the help of CGN.
 
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