How much pressure do primers produce?
- Thread starter titanxt
- Start date
I have seen data where 5,000 psi for #34 primers used in M80 rounds. A load cell was placed in the breech face and the firing pin went through it.
Now does it really matter how much pressure a primer produces??? It is part of the ignition train that we are stuck for our current design of small arms ammunition and adds to the whole process.
Primers back out of the pocket where fired, even some if not most crimped in primers.
The primer pressure is not contained when there is NOT a flash hole. Fire a primer in a case without a flash hole. The pressure is relieved by blanking the cup at the firing pin, or if there is enough headspace when the case is driven into the chamber the primer will fall out. ( I have done these test to show Picatinny Arsenal engineers about ammunition defect severity).
My point is what pressure area are you looking for, pressure in the case from the primer, or pressure in the primer pocket that translate to pressure against the bolt face?
In our world of reloading we select a primer from the menu and test for accuracy. The primer that gives you least amount of standard deviation is the key. My 6MM Dasher needs the CCI 450 and my 45-70 with black powder shoots best with a Remington 2 ½ pistol primer.
Now does it really matter how much pressure a primer produces??? It is part of the ignition train that we are stuck for our current design of small arms ammunition and adds to the whole process.
Primers back out of the pocket where fired, even some if not most crimped in primers.
The primer pressure is not contained when there is NOT a flash hole. Fire a primer in a case without a flash hole. The pressure is relieved by blanking the cup at the firing pin, or if there is enough headspace when the case is driven into the chamber the primer will fall out. ( I have done these test to show Picatinny Arsenal engineers about ammunition defect severity).
My point is what pressure area are you looking for, pressure in the case from the primer, or pressure in the primer pocket that translate to pressure against the bolt face?
In our world of reloading we select a primer from the menu and test for accuracy. The primer that gives you least amount of standard deviation is the key. My 6MM Dasher needs the CCI 450 and my 45-70 with black powder shoots best with a Remington 2 ½ pistol primer.
bigedp51
titanxt said:
The "pressure" generated by a primer would depend on the type and brand primer, and the area the primer is confined in.
Think of a cars engine spark plug, the amount of fuel, the cubic inch displacement and the horsepower it generates.
I think there is no answer to your question because I have never seen pressure testing done with all the different cases, calibers and primers.
The best answer was in red_mamba posting "enough to jam the bullet in the barrel". (force, area, pressure) is used with hydraulic pistons surface area)
Maybe its time for CatShooter to chime in with all his test equipment. (if he is in a good mood)
I tried to Google an answer, but I cannot find what I am after. A friend of mine has a relative who just lost an eye due to an exploding large handgun primer. The guy was hand priming 45 ACP cases and a primer went off. The eye Dr said that there was no shrapnel in the eye and that the tissue damage was due to the over-pressure that the primer produced. An EOD friend and I were trying to track down what kind of pressures primers make.
Thank you!
Andy
Thank you!
Andy
RegionRat
Gold $$ Contributor
A primer being set off using a .45 ACP case as a focus, or nozzle of sorts, will be different based on several variables. In general if there was some distance between that case and the eye, the energy in the propelled gas would be proportional to the distance. My guess is it will fall off very quickly to the sides as well.
I take it the poor fellow wasn't wearing safety glasses and also had it pointed towards their face?
I take it the poor fellow wasn't wearing safety glasses and also had it pointed towards their face?
CatShooter
bigedp51 said:titanxt said:
The "pressure" generated by a primer would depend on the type and brand primer, and the area the primer is confined in.
Think of a cars engine spark plug, the amount of fuel, the cubic inch displacement and the horsepower it generates.
I think there is no answer to your question because I have never seen pressure testing done with all the different cases, calibers and primers.
The best answer was in red_mamba posting "enough to jam the bullet in the barrel". (force, area, pressure) is used with hydraulic pistons surface area)
Maybe its time for CatShooter to chime in with all his test equipment. (if he is in a good mood)
(Grump grump grump)....Some years ago, I was talking to Richard Diez, who was (is) the head of research and engineering at Remington
We started by talking about how strong are the lugs in a Rem 700 action (applied to Win M-70s too). You would not believe how strong they are......
The conversation got around to primers, and Richard said that the primer exerted 700 POUNDS of force, pushing the case forward... now, that is not "psi", it is real pounds!!
Some time later, a friend was over and we got to talking about loading stuff and the subject of primers came up, and I had one of those, "Hold my beer" moments...
So I took a stainless steel pot and stood an empty primed case in the middle of it and put it on the stove.
I lit the burner and promptly receded to the living room to await the pending detonation...
A minute or so later, we heard the expected "BANG", and I went into the kitchen to find a huge dent in the stainless pot (~1/10th" thick) and an empty case sticking out of the ceiling
...So I can personally attest to the following.
Primers have a hellova lot of force on the case, forcing it forward, which is why cases stretch - the primer holds the case into the shoulder until the powder makes the case walls grab the chamber walls, and then the head goes back.
As to PSI in the case - that would vary, depending on the case volume, and how much powder is in it (more powder, less space, more pressure upon ignition... which is a good thing, so says Martha Stewart.
But it would not be much, since it will only sometimes push the bullet out of the case, and they never jam a bullet into the leade.
titanxt said:
Do your own testing. Load up a series of cases using the same bullet and COAl. Just use a different primer for each and leave out the powder.
Fire the case and then run a piece of doweling down the bore, marking it where it enters the crown. Push the bullet out of the bore and repeat.
The one that pushes the bullet farthest into the bore is the "strongest". Just keep a nice long brass rod handy to knock the bullets out of the bore should they actually get that far. Pistols have more of a problem than most rifles with large empty cases.
CatShooter
amlevin said:
A Badddddd suggestion...
Keep in mind that the bullet it a metal bar that is substancially LARGER than the hole in the pipe in front of it - if you get the bullet into the barrel, and it stops... it will NOT ever come out because of the Blish effect (kinda like a bullet's version of a roach hotel).
A good friend has a classic Winchester 1894 with a bullet in the barrel, and he has used wood, and steel rods, heat, oil, and even voodoo dolls, and the bullet has not moved a millimeter!
CatShooter
dedogs said:Cat, How far up the barrel is the bullet? Could an appropriate diameter protective sleeve be built so the bullet could be drilled? Might come out then. Maybe you've already thought of this. Just curious.
It is half way into the barrel - maybe 10" or 12". I think he has given up on it - it is a "sensitive subject" these days
Just how did it get stuck to begin with??
There's a guy on Snipers hide that just had a factory round that didn't have a flash hole... It wasn't real pretty. That was an interesting looking piece of brass.
Screwing around one night at the campfire one night I decided to scare some guys and tossed in a single large rifle primer. For being so small they do have a fair bit of power!
Screwing around one night at the campfire one night I decided to scare some guys and tossed in a single large rifle primer. For being so small they do have a fair bit of power!
What are the last words of a Redneck...?
Hey Boys...watch this...
LOL
Hey Boys...watch this...
LOL
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