pressure signs

[matts318]

I always read on here about observing the pressure signs, but what exactly are all the pressure signs and how do you know when your about at your max when working up a load? I have always stayed below what my reloading manual states as a maximum load but this last year I have really stepped up with the reloading and feel its neccessary to know these things.

thanks in advance

 

[OU812]

My advise would be to look in any good reloading manual (nosler#5) for their discription and pictures of what the various signs of over pressure looks like. A max listed load can be misleading, that is your gun may show signs of over pressure before ever reaching the max listed load or your gun may be perfectly fine slightly over max list load. Always work up to a max listed load slowly. I like to have a spent shell from the lower end of a load to compare with as I work up to max.

Some signs of over pressure are flattened primers, this can vary from slightly flattened to the fireing pin poking a hole in the primer. Bolt lift being a little snug to won't open at all. Ejector marks in the face of the spent case. This can be a little misleading since some brass is softer than other brass manufactures, Norma brass tends to be a little soft.

Weather, mostly heat can take you from no signs of over pressure to over pressure in a hurry. My self I like to work up safe loads in the summer so I can take in account for heat. If you work up loads in the summer with no signs of over pressure would will be good to go during the cooler winter/hunting season months. I have heard of guys loading up some hot loads (max ) in the winter months with no sogns of over pressure but when they shoot them in the summer they have all kinds of over pressure issues.

 

[Glock Man]

OU812 gave a perfect description of overpressure signs. The Nosler reloading guides give a complete listing, and pictures of these overpressure issues.

 

[matts318]

Thanks a lot, I asked because I just worked up a pretty hot load for my 22-250, I got a 50gr. bullet with 40gr of H380, just wanted to make sure it was safe. The primers are flattened a little, you can still see some of the rounded edge of the primer, so I guess thats ok, I compared a loaded one with a fired case and you could barely tell a difference. Im getting the new nosler manual so I will read up on the pressure signs as soon as I get it.

 

[JD338]

+1 to what OU812 said. 8)

JD338

 

[rick smith]

Just be aware there are other conditions that will cause the same signs without any pressure problems. A little too much headspace can cause flattened primers, too much firing pin protrusion or a burr on the tip can pierce primers, sluggest bolt opening can be from dirty brass or chamber, etc. In other words, all things must be considered together, no one by itself is a high pressure sign.Rick.