Several primers not showing much pin strike

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GSells
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Re: Several primers not showing much pin strike

#46 Postby GSells » Sat Sep 30, 2017 11:29 pm

Maybe it's the priming tool ?? I still use an rcbs tool which has done a lot of work ! It maybe it just won't work on .280 Ai brass??

Gyro
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Re: Several primers not showing much pin strike

#47 Postby Gyro » Wed Oct 11, 2017 11:49 am


KHGS
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Re: Several primers not showing much pin strike

#48 Postby KHGS » Thu Oct 12, 2017 6:36 am

Gyro wrote:http://bulletin.accurateshooter.com/2017/10/tech-tip-check-your-primer-tools-if-you-have-primer-problems/


A lot to be said for the "better" priming tool that let you "feel" the primer bottom out in the pocket. I have also seen misfiring of small rifle primers when seated too hard. I had a customer blame a rifle for misfiring, it turned out that he was seating his primers past "bottoming out" after a lesson on how to seat primers he had no more problems. There are no doubt faulty primers around but they are generally rare, in decades of reloading I have struck some, but not many. Another rare cause for misfiring is new cases with very tight pockets & soft cup primers that deform whilst seating.
Keith H.

Gyro
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Re: Several primers not showing much pin strike

#49 Postby Gyro » Thu Oct 12, 2017 8:39 am

Yes. If you scroll down to the bottom of that link, Boyd Allen comments on this subject too. Not that he or me or anyone's necessarily right about this, it's all just useful information on the subject to keep in mind.

Wal86
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Re: Several primers not showing much pin strike

#50 Postby Wal86 » Thu Oct 12, 2017 10:37 am

A friend of mine had troubles on the weekend with primers not going off, cci450.
I checked everything out bolt/firing pin and cases.. im not 100% convinced that pin was hitting quite hard enough but it was a grey area... everything else was Ok
Asked him what priming tool he uses and its a RCBS auto priming tool.. cut along story short his going to get a K+M priming tool.. (there does seem to be a trend with cci450 and RCBS priming tools)

What was interesting is when checking primers this happened...
Loaded rounds that didnt go off on the day, knocked projectiles out with connetic bullet puller emptied powder..... all those cases when put back in rifle all went off? (20cases) not one misfire..
This could suggest that primers are not faulty, but seating maybe an issue?
My mate did say he was conscious of not seating too deep because he was worried about primers not going off. (Unfortunately this is not the correct way to seat a primer and may of been contributing to the problem)

Just a thought hope it helps..

Cheers

Alan

johnk
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Re: Several primers not showing much pin strike

#51 Postby johnk » Thu Oct 12, 2017 12:25 pm

johnk wrote:Just came across this on another forum. Maybe it's worth checking out:

A bunch of our guys in northern England have just had CCI-450 problems too in 308 Palma brass. It seems that the cups of a recently imported batch are shallow and not all priming tools get them fully seated into the pocket with that desired bit of pressure on the anvil. A friend had some FTFs with them (the new lot) seated as usual with his RCBS hand tool. When he tried again with a Sinclair BR type priming tool, the one that has a single primer hand-seated, no magazine, they were OK, but seated 0.006" deeper than the RCBS seated new lot examples or against cartridges primed with older 450 lots that had worked OK.

Anybody been in a position to check this?

bolster55
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Re: Several primers not showing much pin strike

#52 Postby bolster55 » Thu Oct 12, 2017 5:00 pm

Hi,
please see pic below,
Primer on right, failed to fire in Rem 700(about 5), primer on left fired ok. both type of primer fired in Barnard action.
loaded 5 off each primer and shot at 200yds. same loads, cases and projectiles, all touching lands.
primer on left loaded rounds, .5 moa group
primer on right loaded rounds .250 moa group
All BR4's and out of same batch and box!
For what its worth.
Regards
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johnk
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Re: Several primers not showing much pin strike

#53 Postby johnk » Thu Oct 12, 2017 5:11 pm

bolster55 wrote:Hi,
please see pic below,
Primer on right, failed to fire in Rem 700(about 5), primer on left fired ok. both type of primer fired in Barnard action.

Are you able to measure the cup depth of both types of primer?

Postulating, the right ones haven't been punched as hard as the left ones & could just have a deeper cup? :?:

bolster55
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Re: Several primers not showing much pin strike

#54 Postby bolster55 » Thu Oct 12, 2017 5:46 pm

Hello johnk,
a gunsmith said to me after looking at the issue that the primer on the right, may have the anvil seated further away from the cup.
In physics the large area will be able to carry less weight and therefore ignite much more easily than the cup with the larger radius and hence a smaller surface area which in turn can hold more weight (require a heavier strike to ignite).
i will pull one apart and measure a cup of each type, but that will be tomorrow.

bolster55
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Re: Several primers not showing much pin strike

#55 Postby bolster55 » Fri Oct 13, 2017 4:29 pm

johnk wrote:
bolster55 wrote:Hi,
please see pic below,
Primer on right, failed to fire in Rem 700(about 5), primer on left fired ok. both type of primer fired in Barnard action.

Are you able to measure the cup depth of both types of primer?

Postulating, the right ones haven't been punched as hard as the left ones & could just have a deeper cup? :?:


Both types are .120" John
Regards

bainp
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Re: Several primers not showing much pin strike

#56 Postby bainp » Thu Oct 19, 2017 11:59 am

Have just started to prepare the cases I shot at the Ultra Long Range Challenge at Coonabarabran. Again of the 140 cases I shot over the competition and practice day, 7 are showing a very light strike, but all fired on the first attempt. Prior to the trip to Coonabarabran, I disassembled the bolt, washed in petrol and lubricated it with light oil. The spring pressure is more than adequate. I cannot re-cock the bolt with just hand pressure. I must use the tool that is supplied to re-cock.
Out of interest I saved the 7 light strike primers and also selected at random 7 ordinary (heavy) strike primers. Keeping the two batches separate, I washed all in an ultrasonic cleaner to get rid of the carbon.
I dried all with compressed air and then weighed the two batches. I have a Kern 0.1mg Analytic Balance (max range 120gram).
The 7 light strike ones weighed with anvils = 2.1083 grams
The 7 light strike weighed without anvils = 1.5575 grams
The 7 heavy strike weighed with anvils = 2.1028 grams.
The 7 heavy strike without anvils = 1.5518 grams
The anvil weight for both batches 0.5508g (light batch) and 0.5510g (heavy batch), so both weigh very close to each other.
The light strike cups are 0.36% heavier than the heavy strike ones.
Is this difference within the normal range of variation or does it represent a variation that could be causing the difference in the firing pin strike? Maybe there is nothing of concern as all the primers are firing OK.
Philip

bainp
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Re: Several primers not showing much pin strike

#57 Postby bainp » Sun Oct 22, 2017 3:57 pm

Does anyone have any comment????
Philip

Gyro
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Re: Several primers not showing much pin strike

#58 Postby Gyro » Sun Oct 22, 2017 4:25 pm

Nah

johnk
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Re: Several primers not showing much pin strike

#59 Postby johnk » Sun Oct 22, 2017 5:19 pm

Bolster55,

In view of Philip's measurements, are you in any position to comment on the weight of your two different styles of cup?

John

bolster55
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Re: Several primers not showing much pin strike

#60 Postby bolster55 » Sun Nov 05, 2017 6:55 am

johnk,
I'll weigh some today and post later today.
Phil


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