Pressure signs well above max load?

cohunt

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OP- Have you tried measuring case expansion just above the web?
This really can only be done with virgin brass but it can be a good indicator of over pressure loads too
 

Jeffpatton00

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OP- Have you tried measuring case expansion just above the web?
This really can only be done with virgin brass but it can be a good indicator of over pressure loads too
I'm seeing .417" just above the web on new brass, and .421" on fired, unsized brass. Those won't chamber easily or extract without firm persuasion, but I'm surprised that such a small expansion from new would be sufficient to expand beyond the chamber's dimension. The reamer diagram shows .422".
 

cohunt

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I'm seeing .417" just above the web on new brass, and .421" on fired, unsized brass. Those won't chamber easily or extract without firm persuasion, but I'm surprised that such a small expansion from new would be sufficient to expand beyond the chamber's dimension. The reamer diagram shows .422".
 

dogz

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The first thing I notice is you are using book data for a Berger bullet with a Sierra. Then I see that you are 200 fps over the max load published and we both know that pressure equates to speed. You continued to fire hotter rounds knowing there was pressure. Neither the rifle nor components were the same that VV tested. What is the difference in water capacity of VV brass as compared to yours? I tested a rifle a few years ago and found by the time I saw pressure signs I was at 74,000 PSI. I recommend backing way off and starting over. Im sure there is a node at a lower safer speed/pressure. IMO


Bingo..............pressure equals speed and speed equals pressure

Some day, we'll be able to purchase testing equipment at an affordable rate and it'll be fun to see how that goes. Course the red liners will just say that the equipment is off..............grins
 

cohunt

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Bingo..............pressure equals speed and speed equals pressure

Some day, we'll be able to purchase testing equipment at an affordable rate and it'll be fun to see how that goes. Course the red liners will just say that the equipment is off..............grins
It's only about $800 for a pressure trace system, and runs about $35 for each additional strain gauge--- I think its pretty reasonable in price and it's on my list of future purchases, but there are alot of things on that list 😀
 

OrionsStar

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Jul 2, 2012
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I missed it was a gas gun.
I don't know anything about them.
Good learning thread for me.
Thanks to all!
 

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