Primer Smear

[10mmjunkie]

Just got my 10mm Elite Match back from the factory repair center. Sent it in because fired cases have a "smear mark" from the firing pin. The pistol was returned with a brand new match barrel installed. After firing the weapon the new barrel shoots great all bullets in one hole if I can hold it. Unfortunately the smear is still visible on the back of each fired case. I installed a 20lb Wolf spring and that shortens the smear, but it is still present.

Anyone have any suggestions?

Respectfully,

JW

[LPatterson]

First suggestion would be to remove the firing pin and clean the channel.

Second would be to replace the firing pin spring with a new one, preferably an extra power from Wolff.

Not sure it is a problem because most of the brass coming out of H&K's from HLS show the same smear.

[CocoBolo]

Is it primer flow? If it is this can close the firing pin hole in the slide and cause a lot of grief. A picture would help. 10mm pretty hot so I would stick to the harder primers, CCI, MagTech,but no Federals.

[RangerTrace]

Sounds like the primer flow issue I had with my open gun. Do they look like this?

If so, install an extra long firing pin and the problem will be solved.

[10mmjunkie]

Thanks for the great replies. It is not primer flow, just a smear. Tried to take a picture of it but they do not come out. On the back of the case it looks like a comma instead of a period.

Have had pistols do this before and the end result has always been a broken firing pin. If the breach is opening too soon I fear the 10mm operating pressure will blow the case.

I have by chance a couple of Wolf firing pin springs. Not sure if they are any stronger than the factory ones but will give them a try. Will report the results.

Thanks for all the great assistance.

JW

[10mmjunkie]

As suggested I pulled the firing pin, cleaned the channel and replaced the firing pin spring with the wolf extra power spring. No joy. Smear is still present and no shorter than with the factory spring.

Could shortening or using a lighter firing pin fix this issue? Not seeing any horizontal stringing which would be typical of the pistol unlocking to fast. Any help would be most welcome.

Respectfully,

JW

[SLM]

There used to be some talk of this on CZforum a few years ago... Back then the first question asked was "How far is the gun throwing the empties?" The replies usually ranged from 20' to low Earth orbit... The suggestions went in the order of:

1. Stronger recoil spring (which you've already done)

2. Shorten ejector

3. Slightly shorten firing pin

The general consensus was that the ejectors were so long that the firing pin didn't have time to withdraw before the case hit the ejector, thus leaving the common comet tail on the primers. No harm was ever reported from it, it just annoyance and fear of broken pins.

[10mmjunkie]

The low earth orbit is not far fetched with my pistol. As it is reliable I considered it only an annoyance. Any idea on how much the ejector should be shortened? Have small files and a grinder. Would be nice not to have to drive over to the next range to pick up brass (not quite but real close, 50ft is the record so far. They would go farther but we have a roof.)

Please advise on shortening the ejector.

Respectfully,

JW

[kylethunder380]

If I am understanding you, I saw this with my EAA 9mm Match as well. It looked like a 'lolipop', the normal primer dent with a vertical line below it. I was using a very light recoil spring and the load was a little too hot. I swapped the recoil spring for a heavier one and the primer marks went away. In the end, I ended up putting the lighter spring back in and using a softer load because I liked the feel better. I don't think it is going to hurt anything... but it did bother me like it appears to be bothering you. Since a heavier spring didn't work for you, I now have Henning's XL firing pin in my gun and its a sweet part. I don't know if it would fix your 'problem' but it might be worth a try.

-Kyle

[pivoproseem]

I have the same "problem" with my .40 Limited. I'm running a 12lb recoil spring, shooting 167pf 200gr bullets, with a Henning long firing pin, stronger and longer than stock fp spring. I am thinking shortening the ejector may be the ticket. My brass is going @20 ft. I wonder if the general shape of my SP-01 ejector would work with the Tanfo...

If I am understanding you, I saw this with my EAA 9mm Match as well. It looked like a 'lolipop', the normal primer dent with a vertical line below it. I was using a very light recoil spring and the load was a little too hot. I swapped the recoil spring for a heavier one and the primer marks went away. In the end, I ended up putting the lighter spring back in and using a softer load because I liked the feel better. I don't think it is going to hurt anything... but it did bother me like it appears to be bothering you. Since a heavier spring didn't work for you, I now have Henning's XL firing pin in my gun and its a sweet part. I don't know if it would fix your 'problem' but it might be worth a try.

-Kyle

[10mmjunkie]

Kyle,

You are right it does look a bit like a lolly pop. Have already replaced the springs with Wolf extra power with only a slightly shorter stick on the lolly pop. My anxiety is from seeing this in other settings. In one case the firing pin broke repeatedly every couple thousand rounds or so. In the other the slide was unlocking to fast and the case ruptured blowing out the extractor injuring the shooter to the right and blowing out both the mag and fractured the grips. All injuries were minor, the gun was repaired by a good gunsmith who resolved the issue. The owner of the gun wound up paying for two peoples trips to the ER plus the gun repair. Guns that are not functioning the way they are supposed to can be dangerous not only to the shooter but those around them. If I can not get this pistol to work properly then it will have to be destroyed or sold as defective. Anything less would be irresponsible.

Still looking for information on how much the ejector should be cut. If that is the answer it would be good news indeed.

Respectfully,

JW

[GrumpyOne]

I have 2 Springfield P9 factory comps in 40 S&W. I have seen the same effect on the primer as what you describe. To my knowledge, there should be no harm in continuing on the course that you are on now. If it is ejecting properly, and feeding properly, now worries mate...I would like to add though that I have broken more than one using hot loads in the 40, but no injuries, it just seems like metal fatigue....YRMV however.

[Guy Neill]

Firing pin wipe is, as I understand it, caused by the firing pin not retracting before the barrel ramps down. If so, the length of the ejector should play no part. You should be able to determine this by looking at extractor marks in comparison with the direction of the firing pin wipe.

The bottom line fix would seem to have the barrel fitted with the dwell before ramp down maximized as much as possible. You might measure the amount of ramp-down, and the dwell before ramp-down. It may be better yet to look at the amount of upper lug engagement, with the thought that more engagement can translate to a longer time before ramp-down.

This may also be a case where the amount of radius on the firing pin stop plays a part. A smaller radius means the slide will need to work harder to push the hammer back, hopefully increasing the time it takes the slide to move to the rear, and, thereby, ramp-down.

Good luck.

Guy

[Nealio]

Mine smears on my 10mm match also. I notice that I get smear when I run hot 185gr .45 ACP loads in my Para also, so I'm not concerned with it. I've looked at tons of brass at the range and I see others guns that smear like that also. You could put a stiffer firing pin spring in to help. I've put 1500 rounds of hot handloads through mine with ever single on smearing and haven't had any issues (yet). I take my whole top end apart frequently to inspect and clean it and I haven't noticed anything wearing on the firing pin.

However I probably should get a stiffer firing pin spring.....

- Nealio

[Qbert]

I think Guy Neill hit the firing pin on the primer, so to speak.

[CHA-LEE]

This can be caused by two main things. First, if a light slide spring is used which allows the barrel to unlock and drop down pretty easily/quickly then you will get primer swipe. Secondly, if the firing pin is moving slowly due to either a weak firing pin spring or the firing pin channel is dirty this will allow the firing pin to still be extended out towards the primer as the barrel unlocks and starts to drop down. Since you already tried a heavier slide spring, I don't think that its a speed of the barrel unlocking issue. I think you have a speed of the firing pins ability to retract issue. Have you tried replacing the firing pin spring? Have you tried a weaker hammer spring? Are you sure that firing pin channel is clean and not causing the firing pin to bind as it moves? If I was in your shoes I would clean the top end thoroughly making sure that the firing pin, firing pin block and firing pin channel were very clean and properly lubricated. Then I would put a new firing pin spring in it and then put a hammer spring that was 2 - 3 lbs weaker than the stock one is. You will need to play with the hammer springs to see which one will reliably light off the primers with the stock firing pin, but once you have that tuned up you will know that the firing pin is only being stuck with enough force to do its job and nothing extra. I think the lowest hammer spring you can use with the stock firing pin is 15lbs. But every gun is different so do some testing on your own.

An alternate option would be to swap the stock firing pin with one of Hennings XL firing pin. Even though this firing pin is longer it is a lot lighter than the stock firing pin. Since it is lighter and longer you can also use a softer hammer spring as well. For example, with my Limited .40 pistol I use the XL firing pin with a 13lb hammer spring. This gets me consistent solid primer strikes with zero swipe issues, and this is when using a 10lb slide spring which promotes a fast unlocking of the barrel when it fires. The only drawback to using Henning's XL firing pin is that it does not work with the factory Firing Pin block. So you have to remove the firing pin block to use the XL firing pin.

[10mmjunkie]

To all thanks for the great information.

Cha-Lee, Have already cleaned the firing pin channel and used a Wolf extra power spring with no result. Will shoot this weekend to determine directionality of the smear (vertical or horizontal). If horizontal I will try the Henning firing pin to see if that fixes the problem, though I have had no luck calling him this past week. Not happy that this would disable a safety on the weapon but the extra power firing pin spring eliminates the problem the firing pin block mitigates (drop fires).

Guy Neill, Your point about the radius of the firing pin stop is interesting. Not sure where I could find a sans radius one to work on. Do you have any suggestions?

Respectfully,

JW

[Guy Neill]

I don't know of any availability offhand, but you might check with George Smith at EGW and see if he may be able to help.

Guy

To all thanks for the great information.

Cha-Lee, Have already cleaned the firing pin channel and used a Wolf extra power spring with no result. Will shoot this weekend to determine directionality of the smear (vertical or horizontal). If horizontal I will try the Henning firing pin to see if that fixes the problem, though I have had no luck calling him this past week. Not happy that this would disable a safety on the weapon but the extra power firing pin spring eliminates the problem the firing pin block mitigates (drop fires).

Guy Neill, Your point about the radius of the firing pin stop is interesting. Not sure where I could find a sans radius one to work on. Do you have any suggestions?

Respectfully,

JW

[CHA-LEE]

10mmjunkie> Henning is currently out of the office attending the Single Stack Nationals. He should be back on Monday.

[10mmjunkie]

Fast update.

Smear is on the Y or vertical axis. In this case extraction and ejection appear not to play any part. Not sure why there is no vertical stringing. Re-cleaned the firing pin channel and tried a different wolf extra power firing pin spring. No joy. Smear is still present.

The fix, seems to me, is to somehow increase the time the barrel is in battery while decreasing the time the firing pin is actually in contact with the primer. Contacted Henning and hope to meet him in Denver on Tuesday to get one of his light firing pins (and a fiber optic sight...and a guide rod ... and grips... I want it aallll!) Ok I am back under control.

Other random thoughts.

Would using the EGW slide stop pin that is .003 taller increase the friction enough to delay the initial set back of the slide and barrel?

Would the use of stronger hammer springs do the same?

Is it possible to decrease the energy transfer of the hammer to the firing pin by honing the back face of the firing pin?

Is it possible to decrease the depth of the firing pin by placing a shim between the firing pin spring and the firing pin?

Thanks to all for your kind assistance and advise.

Respectfully,

JW

[CHA-LEE]

The lock up and unlock timing of the barrel is done by the kidney on the bottom of the barrel and how it interacts with the slide pin. If you tighten up the tollorances between the kidney and the slide pin by using an oversized slide pin it will speed up the unlocking/locking process, not slow it down. But I doubt that the primer smear is an unlocking timing issue on the barrel.

It is more likely that the hammer spring is way too stiff and its hitting the firing pin with too much force. The harder the firing pin is hit the longer its contact with the primer is going to be. You can speed up the movement of the firing pin (in both directions) buy lightening it. You can reduce the force needed to move the firing pin forward to contact the primer by lengthening it. Hennings XL Firing pin achieves both of these things. Once you have a lighter and longer firing pin you can use a WAY lighter hammer spring which further reduces the strike time of the primer. Less strike time = less chance of primer spear.

Get an XL firing pin and 13lb, 14lb, and 15lb hammer springs. Install the firing pin and the 13lb hammer spring then test fire the gun to make sure it lights off the rounds then check for smear on the primers. If the 13lb hammer spring is causing light strikes then switch to the 14lb and retest. Go with the lightest hammer spring that still enables 100% ignition of the primers. If you still have primer smear after that you are probably tapped out on what you can do easily other than sending the gun to a gunsmith and having him retime the kidney on the barrel. The way I see it, you only need to be worried about primer smear when its excessive enough to show evidence of the firing pin catching on the outside edge of the primer pocket. If that is happening you will have a very good chance of bending or damaging the firing pin because its hitting the hard brass of the primer pocket before its retracting back into the slide. If the primer smear is totally contained within the primer its self then its not too big of a deal because the primers are relatively soft when compared to the brass case.

[10mmjunkie]

Have received my Henning XL firing pin and have installed same. Will shoot tomorrow afternoon. Fingers crossed that this eliminates the problem.

Just for added information. Henning is just as friendly in person as he is helpful on the phone. He is truly a first rate shooter and a very pleasant man.

Respectfully

JW

[10mmjunkie]

Joy at last!!!

First firing with the Henning XL firing pin actually regressed the situation. The firing pin mark was all the way back out to the case again. When I took it out and once again cleaned the channel I neglected to put the firing pin spring back on the firing pin before I dropped it in. To my surprise the pin did not fall all the way through. I got out a bore light and sure enough there was a small burr on the back side of the firing pin hole. A little work with a dental pick, a hand turned small drill bit and a serrated edge knife sharpener did the trick.

Tested with the factory spring and firing pin and the smear came back. Using a wolf spring and it disappears entirely. Will continue to use the XL firing pin with the Wolf spring and keep the factory as a back-up.

Thank you one and all for you kind advise.

Now if I could just keep it from launching my precious 10mm brass into Idaho...

Respectfully,

JW

[CHA-LEE]

Glad to hear that you got it figured out. As for the brass getting sent into the next state, there isn't much you can do about it. My .40 Limited gun sends the brass forward and to the right about 7 - 10 yards. From what I have hard the 10mm guns send the brass even further. I personally don't care where the brass ends up as long as the gun is cycling and functioning correctly. I think that the EAA/Tanfo brass launching is just normal for these guns. Everyone I know that shoots an EAA/Tanfo has the brass sent for a long trip down range.

[JJH]

Congras on figuring out the primer smear problem. A guy I know put up a couple pics on the CZ clone club site of the ejector mod he did to keep the brass in the same county. It's a proceed at your own risk deal, but it works in his gun. 10mm Ejector mod

Edited May 11, 2010 by JJH