Pressure signs - What are they

M

MNDog

Member
I am new to reloading and have been loading by the book and mostly plan to continue. I do however have a question as to what pressure signs are. I am just looking to expand my knowledge base with some insight from the vast experience here. Hopefully it will help others also.

Thanks
 
You might try the 'search' feature and expand the time factor...I know that in the past, there were some threads that included photos of examples, as well as good explanations for excessive pressure signs...

Usually, if you are starting to see your primers flatten out even with the base of the case, or the extraction starts presenting a problem, you can safely think that you are hitting the limit....

If you look at the spent cases and the lettering on the head stamp appears to have started to flatten, then you are probably quite a bit over pressure...Loose primer pockets on fairly new brass is another sign..

Obviously, split or separated cases should not happen with fairly new brass. It will happen once in a while with 'overworked' brass that has been reloaded and re-sized several times, unless you anneal them on a regular basis and even then the primer pockets will start to loosen up..

I have several thousand rounds of .223 brass, some new in the pouch, the rest is mostly once fired.... I generally will use 200 rounds that I will work with until it deteriorates and then pitch it and grab another 200...

I will prep a lot of it to the point of priming it and then store it so all I have to do is drop the powder charge and seat the bullet.. It's easier to keep track of the condition of the brass that way..
 
Without proper equipment reading pressure is an inexact science. Guy's good at it read several signs and recognize danger signs. The danger signs would be hard extraction and loose primer pockets. A loose primer pocket means the head of the case has greatly expanded. With a loose primer pocket on a good case you will likely also see and extractor mark on the base of the case. Hard extraction is the case expanded to much and the chamber probably swelled a bit. The chamber came back down and the case didn't. I don't think split necks indicate much other than case condition or improper champhering after trimming. The necks are probably brittle and split as they expand. Or it could be that when you champhered the mouth after trimming, you champhered to much, that will cause a good case to split.

There are other signs to watch for that may or may not indicate pressure. Flattened primer's could be pressure or could be soft primer cup's. Watch out for the flattening Turtle talked of! Crattered primers could be pressure or could be an enlarged fireing pin hole. Case head seperation is not a sign of pressure but rather a sign of excessive headspace. It can be adjusted for with the FL die. I don't give case head expansion much thought unless it goes over the SAMMI spec or come's close. Fire a round one time and there will be some expansion measurable.

One other thing that indicates pressure to me is an extractor mark on the case head. A case that is driven back into the bolt body hard enough to do that indicates to me that I'm pushing it.

One thing I forgot. If you think it might be pressure, consider that it is till you find out better. Limbs are hard to replace!

 
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Hey Minnesota,
I just got my new Handloader magazine. They have many many examples of pressure signs and cut away shells explaining the different pressure signs. You'd be wise to latch onto a copy of that magazine.
 
Yukon21, Thanks for the tip on the Handloader Magazine... I just signed up for their free copy on the website...I haven't run across it on the racks before...It might be a worthwhile subscription..
 
If you stop load development at 1 grain less than the maximum manual load for the respective bullet/powder combination pressure will not be a problem 99% of the time.

And, keep reading and apply what you read to analyzing your own fired cases.
 
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