Several primers not showing much pin strike

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bainp
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Location: Wagga Wagga, Australia

Several primers not showing much pin strike

#1 Postby bainp » Wed Sep 13, 2017 5:09 pm

I have recently shot the SA Match Rifle Championships and I am now preparing ammunition for the next matches.
I have found that of the 125 or so rounds that I fired at the SA Champs, 5 cases are showing very little firing pin strike.
The rifle action is a Maddco. Although the firing pin spring is some years old, it doesn't feel like it has degraded. The spring was upgraded by Maddco some years ago. At the time I understood that the replacement spring was made from chrome silicon wire as are valve springs and that it probably last my lifetime.
I always leave the bolt uncocked during travel and storage. The internal of the bolt tube, firing pin and spring are well lubricated with Tetra Gun Fluoropolymer Grease. This grease doesn't seem to thicken considerably in cold weather.
The primers I use are CCI 200. This is a new batch of primers. All are still showing rounded edges after firing and the primers that have the normal indentation do not show any cratering around the pin strike.
The cases were previously fired and had only been neck sized.
The load I use is a good stiff load, but not to eye popping proportions. The cases are very old (many years) but not showing any signs of primer pocket expansion.
Has anyone got any idea why a few cases/primers in the batch would show a light strike :?:
Regards - Philip

6.5x55ai
Posts: 141
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Location: Waikato NZ (Ex Tyabb)

Re: Several primers not showing much pin strike

#2 Postby 6.5x55ai » Wed Sep 13, 2017 5:28 pm

For a start check your firing pin protrusion, IIRC should be around 50 - 60 thou. (Others will correct me). How deep are your primer pockets? How deep are your primers ending up being seated? What do your primers in depth measure - I generaaly find the ones I use canaverage128 thou ish.

You say that you are on a new batch of primers - was there any issues with the previous ones? Were they CCI 200s as well?

One cause can be excessive FLSing but this usually results in flat primers - often mistakenly assumed to be caused by high pressure. Mmmm discount this as you say you neck sized.

You say you decock your bolt - what is your impression of the force required to recock it?

Wal86
Posts: 68
Joined: Sun Nov 20, 2016 5:10 pm
Location: Kilmore, VIC

Re: Several primers not showing much pin strike

#3 Postby Wal86 » Wed Sep 13, 2017 5:36 pm

Philip,

Ive heard people suggesting that there is a bad batch of cci primers.. I dont believe this at all..
I think that in most scenarios it is related to headspace problems, (new brass or FL sized brass) ect.

You say cases have been fired, but we're they fired in that chamber?
You only need .003" headspace and a projectile seated off the lands, your firing pin will just push the case forward and not make enough contact to primer..
Take firing pin mechanism out of bolt body, put case in action and close bolt, if there is headspace you will be able to move the bolt body backwards and forwards..

Just a thought hope it helps..

Cheers

Alan
Last edited by Wal86 on Wed Sep 13, 2017 5:55 pm, edited 1 time in total.

Gyro
Posts: 140
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Location: New Zealand

Re: Several primers not showing much pin strike

#4 Postby Gyro » Wed Sep 13, 2017 5:45 pm

Have you thoroughly confirmed it's not a headspace prob ?

BTW my head still hurts after the case neck story lol

johnk
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Re: Several primers not showing much pin strike

#5 Postby johnk » Wed Sep 13, 2017 5:46 pm

Lack of pin strike suggests either that the primer is too far away from the firing pin as already suggested or that you have a burr or foreign matter in the bolt that's slowing the firing pin fall. Wash & lightly oil after checking.

Also worth checking is if the sear piece on the firing pin is rubbing in the action way during fall.

bainp
Posts: 37
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Location: Wagga Wagga, Australia

Re: Several primers not showing much pin strike

#6 Postby bainp » Wed Sep 13, 2017 6:50 pm

6.5x55ai wrote:You say you decock your bolt - what is your impression of the force required to recock it?

I have to use the special tool supplied by Maddco to uncock and recock, if spring was degraded too much, this would be possible to do by hand.

6.5x55ai wrote:You say that you are on a new batch of primers - was there any issues with the previous ones? Were they CCI 200s as well?

I didn't have enough of the previous batch to complete the 125 rounds required for the competition. The previous batch were CCI 200's but from the old look box. I buy primers by the 5000 carton. There were no issues with the old primers

6.5x55ai wrote:For a start check your firing pin protrusion, IIRC should be around 50 - 60 thou. (Others will correct me). How deep are your primer pockets? How deep are your primers ending up being seated? What do your primers in depth measure - I generaaly find the ones I use canaverage128 thou ish.


Yet to check FP protrusion.
All primer pockets have been uniformed, as best I can measure @ 0.132' deep
Primers vary from 0.002 to 0.005 deep, I only have vernier caliper not a depth micrometer.
Primers are about 0.128" also, but the anvil is proud of the edge of the primer cup. I am not going to risk prying the anvil out of the cup to measure the cup.

Yet to check headspace, but this is the same barrel that the previous batch of primers worked OK in.

Wal86 wrote:You say cases have been fired, but we're they fired in that chamber?

Yes all previously fired in that chamber.

Wal86 wrote:You only need .003" headspace and a projectile seated off the lands, your firing pin will just push the case forward and not make enough contact to primer..Take firing pin mechanism out of bolt body, put case in action and close bolt, if there is headspace you will be able to move the bolt body backwards and forwards..

Yet to try this, I have GO and NO GO gauges though. My recollection is that the bolt closes easily even on the fired case

johnk wrote:Lack of pin strike suggests either that the primer is too far away from the firing pin as already suggested or that you have a burr or foreign matter in the bolt that's slowing the firing pin fall. Wash & lightly oil after checking. Also worth checking is if the sear piece on the firing pin is rubbing in the action way during fall.

I will also check this when I can. My rifles are stored at a different location to where I regularly reside. Licensing branch are aware of this.

Thanks for the suggestions - Philip

mike H
Posts: 501
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Location: JUNEE NSW

Re: Several primers not showing much pin strike

#7 Postby mike H » Wed Sep 13, 2017 8:40 pm

Phil,
The way I read your post,you have small indentations on the fired primers,just to make sure of the situation,did the rounds fire?,or did they misfire.? I have plenty of CCI-200 and Br-2's if you would like to try some different ones.

John23
Posts: 269
Joined: Mon Oct 29, 2012 9:11 pm

Re: Several primers not showing much pin strike

#8 Postby John23 » Wed Sep 13, 2017 9:01 pm

Before you spend too much time thinking about the issue I would start simple and strip the bolt down and give it a clean .

If it has always worked for you it still probably should

jasmay
Posts: 876
Joined: Fri Sep 28, 2012 9:26 pm

Re: Several primers not showing much pin strike

#9 Postby jasmay » Thu Sep 14, 2017 8:53 pm

Wal86 wrote:Philip,

Ive heard people suggesting that there is a bad batch of cci primers.. I dont believe this at all..
I think that in most scenarios it is related to headspace problems, (new brass or FL sized brass) ect.


Cheers

Alan


What leads you to this opinion? Have you inspected a rifle with this issue?

Over the past 12months I along with some very experienced shooters, several of them on the world team, and also shooters that I met over there, also, very experienced noted having the same issues.

I have had this problem with CCI in one rifle.

I normally use FED205, I switched to CCI BR4's for a period and experienced this issue on both new and fireformed brass.

I do not uniform pocket depths for fear of over doing it, and, the latest batches of Lapua really don't need it. After checking over the fireaem, I went back to Federal and no more issues.

Another prominent shooter running a rifle for his son experienced this in both rifles after moving into a new batch of primers, same make, different batch, switched to Remington, and problem gone.

I'm sorry, but there have simply bee far too many experienced shooters who all of a sudden are having this issue to simply say "I don't believe it"

If not other reason for lite strikes or failure to ignite can be found, surely it's time to look at the primer itself.

Wal86
Posts: 68
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Location: Kilmore, VIC

Re: Several primers not showing much pin strike

#10 Postby Wal86 » Fri Sep 15, 2017 3:08 pm

Jasmay.

I was at a shoot last weekend, and a experienced shooter who shoots very well, who had never had a miss fire in all his shooting career, only to have 5 in one day..(new batch of cci)
During that time the conversations on the mound were about cci primer miss fire this and that and how many shooters are getting primer failures, totally disregarding potential for a reloading error because of the shooter credentials..
I spoke to him that night, he was using new lapua brass and he shoots off the lands..
I said I bet your new brass that miss fired has headspace..
Long story short he went home checked cases and they had .006" headspace..

I also notice from time to time that case head separation happens quite alot at shoots, which is a result of over FL sizing brass... (which creates headspace)
Also cci primers are a harder/tougher cup than federal

I was only giving an opinion to help out another shooter, who was having troubles...

And ive never had a miss fire with any primer manufacture, not saying it isn't possible to have a Crook primer but if you happen to manage 3 or 4 miss fires at a shoot then odds are it's a reloading/firearm issue..

Cheers
Alan
Last edited by Wal86 on Fri Sep 15, 2017 5:31 pm, edited 1 time in total.

Gyro
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Location: New Zealand

Re: Several primers not showing much pin strike

#11 Postby Gyro » Fri Sep 15, 2017 4:45 pm

Shooting new cases with the projectile "off the lands" is surely a fundamental error ? It sure is in my book !

Gyro
Posts: 140
Joined: Sat Jun 10, 2017 2:44 pm
Location: New Zealand

Re: Several primers not showing much pin strike

#12 Postby Gyro » Fri Sep 15, 2017 5:36 pm

And if you commit the above sin with the ejector still live then you're probably in the same place as the young fella who thinks he's doing the right thing by proposing to the skanky girl he's just gotten pregnant .... ie. you've just compounded the error !! Cheers.

cheech
Posts: 35
Joined: Wed Jul 15, 2009 11:10 pm

Re: Several primers not showing much pin strike

#13 Postby cheech » Fri Sep 15, 2017 8:16 pm

In my Palma brass I have only ever used CCI 450 magnum primers (different batchs) used in three different actions and five different barrels in last 3 years not one problem other than a couple accidentally seated upside down , I FLS when necessary , seat off the lands but jam a little to fire form new ones , I use 21ST century priming tool with tray and depth adjuster so far all good

mike H
Posts: 501
Joined: Mon May 08, 2006 5:34 pm
Location: JUNEE NSW

Re: Several primers not showing much pin strike

#14 Postby mike H » Fri Sep 15, 2017 8:54 pm

The whole thing about new reloaded cases needing to be jammed into the lands for the first firing to stop misfires is concerning to me,if there was any validity to this idea,factory rounds would be giving a fair percentage of misfires,as far as I have seen,this is not the case.
What is going on?

Gyro
Posts: 140
Joined: Sat Jun 10, 2017 2:44 pm
Location: New Zealand

Re: Several primers not showing much pin strike

#15 Postby Gyro » Sat Sep 16, 2017 4:07 am

Absolutely agree Mike H. I only do it because of having read long ago that's what you do and it makes sense to me when you understand the dynamics of case separation.

Perhaps the original problem here with this guys misfires is a combination of a bunch of all these factors occurring together as I would hve thought the headspace would need to be miles out to cause misfires on a well operating firing pin ?


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