Hitting primers too hard.

[Tok36]

   There is much discussion on the subject of light strikes and how too avoid them when using a reduced power Hammer Spring in CZ 75 variants here on the forums. It has occurred to me a few times lately, what about the other side of the equation, hitting a primer too hard. What are the actual risks of hitting a primer too hard?

   For example if one where to run an Extended Firing Pin/Reduced Power FP Spring with a factory weight Hammer Spring or even an increased weight Hammer Spring, what are the actual risks? I have heard of piercing primers but i have never seen an example. If you do pierce a primer what happens? Dose it cause damage to the pistol/brass or both? How common are pierced primers?

[SI VIS PACEM PARRABELLUM]

I've never seen or experienced a pierced primer but I think if that were to happen you are likely to get a dose of hot gas coming out of the ejection port or blowing down the magwell or blasting back into the firing pin channel none of which good. I think you need some inordinate circumstances for that to happen. I think the situation you mention might set the gun up to have firing pin drag which may not be a good thing but then that is a common occurrence in many of the micro compact pistols today.

[M1A4ME]

I've had (several) pierced primers in a .300 BO carbine.

Stopped using those primers.  No damage to the face of the bolt but there probably would have been if I'd kept at it.

I've heard of some brands of brass being bad for expanded primer pockets.  When people continue to use it they get a sort of rounded area of erosion on the bolt face (in rifles).  Sort of a pitted ring around the firing pin hole in the bolt face.

The anvil pretty much has to be against the inside of the feed pocket to insure the cup is smashed into it hard enough to ignite the priming compound.  Can the anvil move upwards, or even collapse due to a harder "hit" by the firing pin?   I've never really examined used anvils when they sometimes fall out of the primer when resizing brass.

If I remember correctly, in the past when I've read about pierced primers the usual suggestions are to insure the right primer is being used and to inspect the tip of the firing pin for damage that might make it gouge/cut the cup metal vs. just put a dent in it.

[Wobbly]

I had a Browning Auto5 16ga shotgun I bought off Gun Broker. The gun was 25 years old, but looked brand new. When received, it looked like it had rarely been fired. Then, when I shot it I found out why... pierced primers. I tried every brand of shell they sold in 16 and the firing pin was simply too long.

As SVPP hinted, very hot gas shoots out through the primer and, like a cutting torch, proceeds to whittle down the firing pin and can erode the bolt face as well. It's not a pretty sight.

[Jim E]

When I changed my firing pin out with the lite kit from CGW, I recall it was around .030" longer than stock. I kind of doubt the round profile of the firing pin could pierce a standard primer given the firing pin channel restricts the forward motion for over travel.
I have to believe CGW did their homework on the extended firing pins or they would have posted a warning to not use with heavier springs. No doubt it could happen if the bolt or firing pin is out of spec.
Just sayin', the only time I've ever had a problem with a primer was with 5.56 NATO in an AR-15. Primer blew out. Rifle was OK...got rid of those rounds and now only use Lake/Federal or PMC.

[mauserand9mm]

Was shooting next to an M14 that pierced a primer. The magazine was blown out of the rifle, and the base plate of the magazine also blew out spiling plate, spring and rounds into the dirt. I got blasted by pebbles in the dirt. The empty case was still in the chamber meaning that the pressure drop didn't allow the action to fully cycle. Was a faulty primer in ex-mil ammo - I don't recall what make the ammo was, and this was the only time I heard of t doing this. IIRC the M14 bolt has a vent hole in the underside.

[Tok36]

Interesting stuff. I did not consider gas escaping through the pierced primer hole. It had not occurred to me that FP drag on the primer may be a warning.

I appreciate the input.

[newageroman]

I've had one pierced primer when shooting up the ladder loads for 6.5 CM bolt in RAP.
Mine wasn't near as abrupt as the others here, I had been working up a ladder load by .2 gn each. After that I stopped for the day and adjusted max charge to well under that load. Action was just dirty, I suspect gun would have fired again. There was no holy crap moment, but it did sound different. I can't remember if I had mag in or now, most likely single feeding them watching closely for pressure signs.

[newageroman]

I have another question about primers and spring weights that is relate to this, which I had just recently been pondering and discussing with a friend.
It seems there may be a trade off when loading hot rounds with soft (fed) primers and cushy light springs. I'm sure someone here has been in this decision point.

If the pressure is high, it might be worthwile to consider using stiffer springs and harder primers, to contain the effects of cratering/piercing more.
So the CON or inverse of that would be...
Hot round with Soft primer, and soft springs, but you get pressure signs sooner and run the risk of piercing primer. But you have a super cushy trigger.. so what, cant be used reliably if can't make maj. PF.

.. also related - would it be worthwile to work up a load using soft primer on purpose to show the signs of pressure, THEN switch to hard primers, knowing where the soft primer pressure limit is? Just throwing out ideas here, please chime in. I'm also STILL of the camp that just loads "in the middle"  of the range almost all the time. I'd rather adjust holdover  a tad more than to push everything to the max all the time and worry about all the variables at threshhold every single shot.

[Wobbly]

I don't shoot high or extremely high pressure rounds, but I do think that you start with the primers you want to shoot. There are differences not only in cup thickness between brands of primers, but also the chemical composition. If you're making and testing up a new-to-you load, you don't want a new primer changing everything after the test is completed. Why would you do that ?

Two primers would mean you'd need to run parts of the test again, after the testing is "over". Meaning your testing time would be extended. Well, really meaning that the first go-round wasn't "testing" at all, it was dorking around gathering useless information which you knew from the start wasn't going to be applicable to anything.

And what would you learn ? You'd learn that Federal primers have softer cups. Well, every reloader on the planet already knows that.

No, the entire object of any good test is to set up a situation where only 1 variable changes... in this situation it's the powder load.

 

[M1A4ME]

Some people that run the "hot" loads use small rifle primers.  Their claim/reasoning is that small rifle primers and small pistol magnum primers are pretty much the same primers with respect to cup thickness and how powerful the primer is when lit off by the firing pin.

You know, looking at it from the DA/SA, weaker spring side....

Why the reduced power springs and longer firing pin?  To reduce the double action trigger pull weight.

I've seen it here, and other forums, that weaker hammer springs don't really have a positive effect on SA trigger pull.  Some people say increasing the hammer spring power can actually make the SA trigger pull crisper/better feeling.

So, how many shots from a 15 or 19 round 9MM magazine get fired DA? 

Are people reducing SA trigger pull feel/crispness to make a small percentage of the DA shots feel better/easier/smoother?

I'll admit, I have DA/SA CZs that have never been fired DA.  Probably most of them.  Might not have ever fired DA except when dry firing.  So I'm no DA trigger expert.

I have installed the extended firing pins, lighter firing pin return springs and lighter hammer springs in a couple CZ75 types.  Can't say it benefited me at all, but I did it anyway.  I have installed the CGW lighter trigger return springs and firing pin block springs in my P07/P09 pistols.

So far I've never had a pistol blow through a primer.

I've also read (hear and other forums) that identifying pressure in pistol brass/primers - by looking at the primers or base of the brass case is pretty much impossible to do.  You don't run the same pressures in most semi auto pistols you do in rifles at normal rifle pressures you shouldn't even see flattened primers, cratered primers, ejector marks, etc. in rifle brass.

Just some things to consider.