Primer Strike Curiosity

[Redstate]

Curious about the Kahr primer strikes. I know the Kahr Operating Instructions (page 23 on mine) state "..., you may notice that the primer indent appears distorted or elongated". My curiosity revolves around the extent or lack thereof from one Kahr to another.

My MK9 primer strikes (most of them) are extremely distorted or elongated to the point that the primer is smeared out passed the edge of the primer, and almost onto the case. The strikes are very deep. See photo below for the MK9 primer strikes.

My K9 primer strikes (most of them) are distorted or elongated as well but not past the edge of the primer unlike those of those of the MK9.

My friend's CW9 has most of the primer strikes with very minimal distortion or elongation. These also appear to be less deep than those of the K9 and MK9.

It would be appreciated if you could explain or show the degree of primer distortion or elongation on your primer strikes while stating the model of pistol. Opinions are welcome. Thanks.

[berettabone]

MK9..........2001 model.................no pics...............................My strikes are even more elongated, first time I saw them, I kind of freaked a bit. Sometimes a bit off center also.

[tony k]

Before my slide was replaced on my CW45, the elogations extended past the primer and were way off center, leaving firing pin marks on the inner edge of the primer pocket. With new frame, they all stay within the diameter of the primer.

My CM9 primers are also way less than what you show in your pics.

yours look pretty extreme. Sorry, I don't have any pics for comparison handy.

[Redstate]

MK9..........2001 model.................no pics...............................My strikes are even more elongated, first time I saw them, I kind of freaked a bit. Sometimes a bit off center also.

Thanks. Are you saying that your primer strikes are even more smeared than on mine? As you can see in my photo, they smear off the primer perimeter and to the case. I should note that it has run flawlessly with over 1000 rounds through it.

[Redstate]

Before my slide was replaced on my CW45, the elogations extended past the primer and were way off center, leaving firing pin marks on the inner edge of the primer pocket. With new frame, they all stay within the diameter of the primer.

My CM9 primers are also way less than what you show in your pics.

yours look pretty extreme. Sorry, I don't have any pics for comparison handy.

Thanks. I will try to post some photos of my K9 primer hits and my friend's CW9 primer hits referenced in my original post.

[muggsy]

This is nothing more than primer smear and quite normal in striker fired pistols. The striker doesn't retract until the slide moves forward toward battery after the fired case has been ejected. If you read your owners manual you would be aware of this. Of course we all know that a true gun expert only reads the manual as a last resort.

[tony k]

Of course we all know that a true gun expert only reads the manual as a last resort.

Also true for ammo reloading, chainsaw operation, aircraft maintenance, and brain surgery ;)

Seriously though, if the guns are operating properly, I wouldn't worry too much.

[Redstate]

Okay, here is a magnified set of photos. The first two are of the same primers in the photo in my original post.
The last one is of a primer from my friend's CW9. I plan on using my K9 tomorrow and will post a photo when I can.

[Ikeo74]

A nice clean gun will have a deeper primer strike than a gun that has an accumulation of oil and crud in the striker channel. There is also a difference in the hardness of the primer metal. Softer primers will have a deeper indentation. The amount of recoil also plays into the strike indentation. +P loads will be deeper than target ammo. What it boils down to is (don't be concerned about it) unless the strike is so light it doesn't ignite the primer, or so deep it allows gas to escape out of the primer strike hole. If you have consistant light strikes then you need to clean the striker channel.

[berettabone]

Thanks. Are you saying that your primer strikes are even more smeared than on mine? As you can see in my photo, they smear off the primer perimeter and to the case. I should note that it has run flawlessly with over 1000 rounds through it.
Sometimes, yes.....................

[Redstate]

Sometimes, yes.....................

Thanks, I appreciate you.

[Redstate]

Now I have some magnified photos of the primer strikes from my P9 Covert. These are minimal compared to the MK9.

[Redstate]

Here are the magnified photos of the primer strikes from my K9. These are more elongated or distorted than those of the P9 and are not as much as those of the MK9.

What have I learned from this? The 4 guns are all different as far as the amount of elongation or distortion. The ammo brand seems to make a difference. Also, probably a mere coincidence, with the polymer guns the amount of elongation or distortion was less than with the steel guns. Also of possible note is that the MK9, the shortest of the 4, had the most elongation or distortion. Trying to be scientific about this; but don't have enough pistols to sample. So, the conclusion is that I have no conclusion why there is a difference between the various pistols.

Again, opinions, as well as descriptions of your primer strike appearance or photos are welcome. Thanks.

[sas PM9]

Here are the magnified photos of the primer strikes from my K9. These are more elongated or distorted than those of the P9 and are not as much as those of the MK9.

What have I learned from this? The 4 guns are all different as far as the amount of elongation or distortion. The ammo brand seems to make a difference. Also, probably a mere coincidence, with the polymer guns the amount of elongation or distortion was less than with the steel guns. Also of possible note is that the MK9, the shortest of the 4, had the most elongation or distortion. Trying to be scientific about this; but don't have enough pistols to sample. So, the conclusion is that I have no conclusion why there is a difference between the various pistols.

Again, opinions, as well as descriptions of your primer strike appearance or photos are welcome. Thanks.


RS:

Something occurs to me; is it possible that the occurrence of the larger/longer smear is due to the length of the barrel on these striker fired handguns? The shorter the barrel, the greater the angle it has to make, the more the back of the barrel moves down when it unlocks during the process thus the longer the smear.
What thinks the forum?

- steve

[Redstate]

Good question Steve. Maybe others will chime in. Thanks.

[tony k]

Barrel attitude, length, etc. Kinda got my gears turning (maybe just grinding)

I'm just thinking out loud here. Maybe ejector or the timing of ejection has something to do with it. Don't forget about the extractor; I'm learning that there is some variation in extractors. That could change how long or how forcefully the case head is held against the breech face after ignition, thus changing how long and how forcefully the primer remains in contact with the firing pin before it ejects.

I'd compare ejectors and extractors between the three guns.

The P9 Covert has the least smeared primers. Notice that the position of the P9 ejector mark is pretty low and further out on the headstamp. The K9 has no detectable ejector mark and a pronounced elongation of the primer strike. The CW9 has a pronounced smear and a highly visible ejector mark that sits higher and nearly touches the primer.

I don't think you have anything to worry about in any case. It is interesting to observe the differences though. thanks for sharing. Lots of food for thought

[sas PM9]

Barrel attitude, length, etc. Kinda got my gears turning (maybe just grinding)

I'm just thinking out loud here. Maybe ejector or the timing of ejection has something to do with it. Don't forget about the extractor; I'm learning that there is some variation in extractors. That could change how long or how forcefully the case head is held against the breech face after ignition, thus changing how long and how forcefully the primer remains in contact with the firing pin before it ejects.



I'd compare ejectors and extractors between the three guns.

The P9 Covert has the least smeared primers. Notice that the position of the P9 ejector mark is pretty low and further out on the headstamp. The K9 has no detectable ejector mark and a pronounced elongation of the primer strike. The CW9 has a pronounced smear and a highly visible ejector mark that sits higher and nearly touches the primer.

I don't think you have anything to worry about in any case. It is interesting to observe the differences though. thanks for sharing. Lots of food for thought

TK:

Yes, that's another way of looking at the query that I posed above.
It sure looks like the shorter barrels are the ones that produce this longer primer smear.
I know that my PM9 and CM9 do exhibit this primer smear but not it to the extent that the OP has shown in the pictures of his MK9.

-steve

[Redstate]

Thanks tony k. Interesting thoughts, and I appreciate them. Actually, the order of smearing, from least to most is as follows: CW9, P9 (note P9 and CW9 are very close), K9 and finally MK9.

[berettabone]

This sounds like " smear tactics " to me.................:p

[muggsy]

Now I have some magnified photos of the primer strikes from my P9 Covert. These are minimal compared to the MK9.

Contact Kahr immediately! Tell them that there must be something wrong with your gun, because you not getting enough primer smear. They should get a real chuckle out of that one. Make sure that you ask for an RA number and a prepaid shipping label. :)

[Redstate]

That's what I call a sense of humor, muggsy. :D

[sanspeu1r]

Right on, it is the result of ejection. I noticed that the case is dirty on just next to the side that the ejection smear appears. My theory is some residual gas from the firing travels along the side of the cartridge beginning its exit. Just an idea.

[Handy]

The short barrel guns probably unlock earlier due to higher slide velocities (lower mass slide), AND short barrels change angle more to cam down at unlock. So I would expect the smear to be much worse on a MK9, and no smear on a T9.

[CPTKILLER]

https://m.youtube.com/watch?v=0RhjvVeeH8s

Watch this, it will explain the phenomenon on striker fired and other pistols.