Excessive Pressure

steelrat · March 21, 2007, 11:44 AM

Another newbie question... When physically looking at a spent load, what are some things I would be looking for to search for excessive pressure?

Keenan Goss · March 21, 2007, 12:45 PM

I would like to know too. I have some old brass I picked up at the range, and some of them have a small hole, or crack in the neck. Is that just an old case or excessive pressure?

chewie70 · March 21, 2007, 01:43 PM

Some of the things that I've learned are:

Bulged or split cases
flattened or deformed primers
signs of gas release between primer and primer pocket

I'm not sure if I'm supposed to post this link here, but I will since it has a very informative section with some excellent pictures of excessive pressure. Just scroll down towards the bottom of the page.

http://www.38super.net/Pages/Factory2.html

Hope this helps!

rwilson452 · March 21, 2007, 07:47 PM

Look at the primer. If the primer is flattend your hot. If the primer has been flattened to the point it has totally filled the primer pocket ( squared edges) your too hot. if the primer strike hole looks like a crater, a raised edge around the primer indentation. your too hot. on the case if you see a bright ring around the case where the head meets the case body your way too hot. in a bolt gun if it's hard to move the bolt your too hot. If you see powder burns around the the primer pocket your too hot.

cdoc42 · March 21, 2007, 08:20 PM

Craters in the primer around the firing pin indentation are not necessarily a pressure problem. Could be soft primers. But craters with bolt difficulty, yes. Usually more than one thing will show up.

I've found difficulty in opening the bolt to be an clear sign of too much pressure. Flat primers may be an earlier sign but that's tough to identify.

Black discoloration around the primer, maybe - but could also be an enlarged primer pocket from frequent reloading. If the primer seats VERY easily, look at it right after you fire it. You may see the results of gases having escaped around the primer. These days when I feel a primer very easily seating, I discard the case.

Web rings or cracks could simply mean you've fired the case too much or you have a headspace situation, especially if the web crack occurs with just a few firings. Cracks in the neck are due to brittle metal from frequent firing. You can anneal them before they crack but I've never bothered. Once I see any evidence of a crack (sometimes just a pin hole) I toss the case.

March 21, 2007, 11:44 AM	#1
steelrat Member Join Date: February 8, 2007 Location: Utah Posts: 66	Excessive Pressure Another newbie question... When physically looking at a spent load, what are some things I would be looking for to search for excessive pressure?

March 21, 2007, 12:45 PM	#2
Keenan Goss Member Join Date: March 5, 2007 Location: Lexington, KY Posts: 27	I would like to know too. I have some old brass I picked up at the range, and some of them have a small hole, or crack in the neck. Is that just an old case or excessive pressure?

March 21, 2007, 01:43 PM	#3
chewie70 Member Join Date: January 29, 2007 Posts: 36	Some of the things that I've learned are: Bulged or split cases flattened or deformed primers signs of gas release between primer and primer pocket I'm not sure if I'm supposed to post this link here, but I will since it has a very informative section with some excellent pictures of excessive pressure. Just scroll down towards the bottom of the page. http://www.38super.net/Pages/Factory2.html Hope this helps!

March 21, 2007, 07:47 PM	#4
rwilson452 Senior Member Join Date: June 10, 2004 Location: Tioga co. PA Posts: 2,647	Look at the primer. If the primer is flattend your hot. If the primer has been flattened to the point it has totally filled the primer pocket ( squared edges) your too hot. if the primer strike hole looks like a crater, a raised edge around the primer indentation. your too hot. on the case if you see a bright ring around the case where the head meets the case body your way too hot. in a bolt gun if it's hard to move the bolt your too hot. If you see powder burns around the the primer pocket your too hot.

March 21, 2007, 08:20 PM	#5
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,772	Craters in the primer around the firing pin indentation are not necessarily a pressure problem. Could be soft primers. But craters with bolt difficulty, yes. Usually more than one thing will show up. I've found difficulty in opening the bolt to be an clear sign of too much pressure. Flat primers may be an earlier sign but that's tough to identify. Black discoloration around the primer, maybe - but could also be an enlarged primer pocket from frequent reloading. If the primer seats VERY easily, look at it right after you fire it. You may see the results of gases having escaped around the primer. These days when I feel a primer very easily seating, I discard the case. Web rings or cracks could simply mean you've fired the case too much or you have a headspace situation, especially if the web crack occurs with just a few firings. Cracks in the neck are due to brittle metal from frequent firing. You can anneal them before they crack but I've never bothered. Once I see any evidence of a crack (sometimes just a pin hole) I toss the case.