Indication of crushed primer

[FieroCDSP]

I've been under the understanding that it's possible to crush a primer without detonating it. Bending of the anvil which prevents later, intentional, detonation behind the bullet.

What are the indications of this?

While running loads in my Loadmaster, I had a feeling that I may have crushed one, but all of my loads were seated identicaly a shad deeper than the case heads. Maybe it just seated rough from a dirty pocket (it was Winchester brass)

 

[The Bushmaster]

No one wants to touch this? I will...More then likely the primer is O K if it looks like the rest of them on the outside. If you haven't seated a bullet in it look inside too and compare with an unseated primer. If you have all ready seated a bullet. May I suggest that you pull the bullet if you are in doubt. Or...Just take it to the range and fire it.

 

[FieroCDSP]

I haven't had any primer problems yet, so I'll trust that it'll go boom when I want it to. I was just curous whether there's a characteristic feel or sound or look to a crushed primer.

 

[Walkalong]

It is tough to crush a primer. If you do you should FEEL that something is wrong and it will be quite a ways past flush instead of just a bit where a primer will normally be.

The equipment we use is what makes it hard to do so. The manufacture's do a good job of keeping us out of trouble, for the most part.

 

[FieroCDSP]

okay. THat's what I was looking for. Thanks Walkalong.

 

[benedict1]

Proper Priming Depth Adjustment on Load Master

Yes, you can get crushed primers or flipped primers with a Load Master if the priming depth is not set properly. If it is not deep enough you get a situation where the slider is moving while the primer seating pin is rising and it will catch on the pin causing the primer to tip, or in an extreme case, flip over.

If you crush one, you will feel it because it will take more effort than normal to raise the shell plate completely. Finish the stroke and immediately pull the case where it has rotated, in station 3. If the primer seating was faulty, you'll see it right there.

For a flipped primer you are only going to see it when you inspect the finished rounds.

If either of these things begins to happen, adjust the primer seating bolt by turning it out to make the seating be deeper. Go slowly--one wrench flat at a time. When the primers are seated correctly they are in the pocket about .001-.002" below the rim of the case and may look slightly flattened. You will find that you will have no more crushed or flipped primers.

Also, be very careful when switching back and forth between small and large primers. The only case I know where a primer detonated was when the user forgot to change the primer pin from small to large. The small primer seating pin acted like a firing pin on the large pistol primer--not good--

Finally, make sure the shell plate knob is tight so the plate doesn't wobble. Keep all grease and gunk off the priming assembly--keep it dry but if you must lube, use powdered graphite on the slider. And, as a rule, always check the case retainer on station 2 before starting a loading session. If it is open a bit then the case will not be in register for the primer pin to seat the primer. To get away from this, I deprime in station 1 and size, without the decapping pin, in station 2. The resizing die does a perfect job of holding the case in the right position. See darwin-te video on this on You Tube

http://www.youtube.com/user/DarwinTe

In his videos on the Load Master setup and operation you will find one that discusses setting the priming depth properly with dies in station 1 and station 2.

 

[Shoney]

When I use the term crushed primer, I am referring to a primer that has gone in the pocket sideways and has been crushed.

In the 46 years and over 75,000 cartridges I have loaded, I have never had a primer detonate in the press. I have loaded them backwards and sideways, and then deprimed these live primers with no ill effect.

To crush a primer in the pocket, you would have to have a primer seating set up where the primer ram would be capable of going up into the primer pocket. Of the 10-12 different presses and 2 different hand priming tools I have used over the years, none could do this.

I have experimentally applied an inordinately great deal of pressure during seating primers, and all the primer fired reliably in a weapon.

 

[Walkalong]

A sideways primer is just an improperly seated sideways screwed up primer. It can happen in any automated primer feed. Sideways, upside down, etc.. I have never detonated a primer and I have seated them improperly a few times.

A crushed primer has been otherwise properly seated, but has been seated so deep and so hard the cup and anvil has been "crushed" together and it does not fire properly, thus giving poor or no ignition. As indicated by both Shoney and I though, this is hard to do with the equipment we use.

 

[Steve C]

FWIW I've mashed the primer flat to get it seated in cases that have a real tight or shallow pocket but usually because there's still some risidual crimp left. Every round has fired though I wasn't sure it would at the time.

 

[The Bushmaster]

Primers tend to be tough little characters and quite forgiving I might add...Hard to kill them...

 

[bfoster]

There's another definition of a crushed primer in use by some riflemen.

In the normal seating of a Boxer primer in a case wherein the primer pocket is formed to a depth within tolerance a bit of a preload is applied to the primer pellet because the legs of the anvil contact the bottom of the primer pocket before the "head" of the primer is seated to the correct depth. Note that the recommended seating depth varies slightly from primer manufacturer to primer manufacturer.

Sometimes things go wrong in the manufacture of cases or primers, on rare occasions products get by the QC folks to the consumer.

The most common problem is an out of "spec" primer pocket. Slightly shallow primer pockets are seen from time to time. If noted, this problem can be corrected by using a primer pocket reamer.

It's easily noted that the assembled height of primers varies considerably: some lots of some brands will exhibit a variance of as 0.015" or more. In practice the result of this can vary from nil to that which can be noted on a target. A few stool shooters do segregate primers by assembled height. Your results will vary with the conditions you encounter- some in your control, some beyond it.

Over the years I've seen a few primers which weren't assembled correctly. This condition is usually obvious at a glance.

I once purchased a primer where one of the legs was too long- probably due to a problem with a die at the factory.

If a primer is seated to the recommended depth in a shallow pocket the handloader may deform or crack the primer pellet without igniting it. In my experience such a pellet will usually fire, the result may be pressure, velocity and point of bullet impact within the normal distribution. Sometimes an abnormal shot does occur under this condition. Such abnormal shots are usually characterized by lower than normal pressure and velocity being developed resulting in a "flyer". I've also seen hangfires, particularly when slower burning powders having a heavy deterrent coating are being used.

The opposite condition can also occur.

I've seen a few cases having a too deep primer pocket.

I've never seen a primer having an anvil with legs too short, but it is possible.

If a normal primer is seated to standard depth in a case having a too deep primer pocket erratic ignition will result (though ignition may still be reliable).

Most benchrest shooters use a Sinclair or K&N seater. These are precision made trayless "cousins" to the familiar hand style seaters offered by Lee & RCBS. The exceptionally high quality of the Sinclair and K&N seaters allows the shooter to "feel" a consistent preload as primers are seated. So long as the primer isn't seated "high" (never a safe condition), or seated unreasonably deep more consistent ignition is obtained.

Bob

 

[FieroCDSP]

Thanks everyone for the input. Despite the time I've been on THR, the wealth of knowledge continues to impress me. I hope when they come to take our guns, some of you guys are next door.

As to my question, I had a primer seem to seat a bit tough, but the more I think about it, it was likely the dirty pocket. Winchester primers seem to be cruddy compared to CCI, which is what I usually use. I adjusted my Loadmaster's primer seater with Uncle Don's instructions, and aside from a flipped primer and one that seated sideways that took some doing to get out of the press, I've had no trouble.

To get the sideways one out, I did a bad thing and set the case on top of the shell plate, then gently raised it till it popped. Obviously I had a problem with a stuck case. I used my lee hand press, screwed in the die with the shell in it, then raised the ram enough to put the shell-holder on the ram and the case head at the same time.