Bad Primers or Weak Firing Pin?

[.50 Cal Cow]

Rifle is a Remington Sendero 300Win Mag. While previously loading with Federal 215M primers I was noticing that every primer was cratering and flatenning regardless of the charge weight (not pressure as there was no issues with bolt lift, ejector swipe etc.). Well hearing that Federal primers are pretty soft I changed over to the CCI 250 large rifle magnum primers and the problem went away. Primers looked like a primer should after firing with a light traditional Rem 700 cratering around the firing pin dimple.

This being said though, I have gone through roughly 80 handloads with this primer but have had 3 rounds where the primers did not ignite. Two were with Hornady brass shooting 210SMK's and 1 with Federal brass shooting 180gr Interbonds. Primers show a mark from the firing pin. Has anyone seen this issue? Is there a way to tell if this is a bad batch of primers or an issue with the firing pin?

Also put 1 box of factory Hornady 195HPBT and 1 plain blue box of Federal 180gr. No issues only that the Hornady rounds had incredibly flat primer.

 

[aloreman]

Re: Bad Primers or Weak Firing Pin?

primers may not be seated all the way to the bottom of the primer pocket

 

[30SMK]

Re: Bad Primers or Weak Firing Pin?

cratering of the primers can happen even with light loads if you have an over sized firing pin hole, but it could be the the primers were not seated all the way or the cases were over sized and the primers came too far out before they were reseated as the base hits the bolt face.

 

[psubond]

Re: Bad Primers or Weak Firing Pin?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 30SMK</div><div class="ubbcode-body">cratering of the primers can happen even with light loads if you have an over sized firing pin hole, but it could be the the primers were not seated all the way or the cases were over sized and the primers came too far out before they were reseated as the base hits the bolt face. </div></div>

i don't think he's too upset about the cratering. that is a known occurrence (that i get the feeling the op knows about already) with newer Remington 700s. it is like that by design or so Remington told me when i called them.

 

[.50 Cal Cow]

Re: Bad Primers or Weak Firing Pin?

Thanks for the suggestions. Yeah the cratering problem I've read in tedium about so not overly concerned.

Just the primer not lighting the load off. In the meantime I'll keep tinkering and be more vigilant with feeling for the primer to bottom out when seating and see if the problem goes away.

 

[30SMK]

Re: Bad Primers or Weak Firing Pin?

My fault for not reading too thoroughly, Which primers did not ignite? 215's or CCI?

Have you broken the rounds apart that the primers did not ignite on? If so were they intact or was the priming compound ignited and some of the powder at the bottom of the case clumped up?

Might try striking them again and see, This also might be a headspace issue, but I doubt that.

 

[427Cobra]

Re: Bad Primers or Weak Firing Pin?

Does your rifle have a J-Lock, if so replace the FPA, if not when was the last time you completely broke down your bolt and cleaned n inspected everything.

 

[YAOG]

Re: Bad Primers or Weak Firing Pin?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: aloreman</div><div class="ubbcode-body">primers may not be seated all the way to the bottom of the primer pocket </div></div>
This sounds right.

 

[YAOG]

Re: Bad Primers or Weak Firing Pin?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Psubond</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 30SMK</div><div class="ubbcode-body">cratering of the primers can happen even with light loads if you have an over sized firing pin hole, but it could be the the primers were not seated all the way or the cases were over sized and the primers came too far out before they were reseated as the base hits the bolt face. </div></div>

i don't think he's too upset about the cratering. that is a known occurrence (that i get the feeling the op knows about already) with newer Remington 700s. it is like that by design or so Remington told me when i called them. </div></div>
The primer cratering in Remington 700 rifles has been going on for many years. My first centerfire rifle was a varmint barreled Remington 700 BDL I bought new 40+ years ago. This Remington 700 has made over 10K perfectly cratered primers on every round of factory and handloaded ammunition. When I get it back from Mike at TacOps it will probably still be making similar craters.

 

[Deadshot2]

Re: Bad Primers or Weak Firing Pin?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: YAOG</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Psubond</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 30SMK</div><div class="ubbcode-body">cratering of the primers can happen even with light loads if you have an over sized firing pin hole, but it could be the the primers were not seated all the way or the cases were over sized and the primers came too far out before they were reseated as the base hits the bolt face. </div></div>

i don't think he's too upset about the cratering. that is a known occurrence (that i get the feeling the op knows about already) with newer Remington 700s. it is like that by design or so Remington told me when i called them. </div></div>
The primer cratering in Remington 700 rifles has been going on for many years. My first centerfire rifle was a varmint barreled Remington 700 BDL I bought new 40+ years ago. This Remington 700 has made over 10K perfectly cratered primers on every round of factory and handloaded ammunition. When I get it back from Mike at TacOps it will probably still be making similar craters.

</div></div>

If you own a Remington with stock bolt expect this. It's just the way it is. If there is no issue with bolt lift then the pressure is in line. Also look for the "half moon" ejector mark on the case head.

Of all the primers I've used in the last 10 years Winchester's seem to be most prone to flattening. A reason I don't even look at primers any more for pressure sign.

 

[.50 Cal Cow]

Re: Bad Primers or Weak Firing Pin?

Thanks everyone. My apologies I probably shouldn't have even mentioned the cratering as thats not really an issue I'm worried.

I had the firing pin out and the assembly cleaned recently. Only about 100 rounds through 3 sessions on a bench so I will inspect it again as its not that hard.

I like the suggestion to pop the primers and see if they look like they are still new on the other side or if they look like the ignited. I will check that next. Hopefully this is something simple like just not seating them far enough.

Thanks again everyone.

 

[QuiggyB]

Re: Bad Primers or Weak Firing Pin?

Ive been told firing pin springs can wear out over time - few thousand rounds - and lead to light strikes. Brownells sells them in two different weights for around $8.

 

[hdbiker1]

Re: Bad Primers or Weak Firing Pin?

I've had similar problems with Fed primers not lighting off. When I tried the same round in an AR, it lit off like normal. I'd suspect weak firing pin spring.
On the subject of Remington bolts and cratering. The practice of beveling the firing pin hole was done in production from 2008 to 2010. Current production doesn't have the bevel. This is according to an email from Remington.

 

[Deadshot2]

Re: Bad Primers or Weak Firing Pin?

One thing to pay attention to is the inside of the bolt, especially the shoulder that stops the firing pin.

Ever notice all those small pieces of brass that are on the bolt face after firing a few rounds? Some of those can migrate up the firing pin channel and get hammered into a washer like ring on this shoulder. The longer you shoot the firearm, the more of this fine material that accumulates and joins that which has been "hammer forged" to the shoulder.

It's not easy to scrape out but given enough time it can reduce the firing pin protrusion. Take a look inside the bolt body next time you clean it and look carefully for something that looks like a spark plug gasket stuck to the stop shoulder.

 

[.50 Cal Cow]

Re: Bad Primers or Weak Firing Pin?

Quiggy - Thanks for the contribution. Not ruling it out but hoping this would not be the issue since the rifle is pretty new. The bolt only has 250-300 firings. Although it has also seen 4 primers blow out from an earlier issue. That has now been resolved under warranty but maybe that put some premature wear on it.

Deadshot - That is awesome info and something I have not look at yet.

Haven't had a chance to inspect the bolt to look for some of this stuff but will soon as I get to. I did pop the primer out of the Hornady case though and found that the primer was intact and the compound did not ignire. Getting more loads ready and paid attention to my primer seating. Will see what happens next trip with the WM.

I think worst case scenario I go back to Fed's and deal with the flat primers or play around with some Tula's or Wolf primers and see if they work better in this rig.

 

[ToxGunn]

Re: Bad Primers or Weak Firing Pin?

How does case length to datum compare on unfired vs fired rounds? I don't recall if 300wm is belted. if not, and If your rounds are significantly short, pin might not be reaching far enough to reach them reliably. My understanding is that in this case you also get flat primers on rounds that do fire, as a result of the primer backing out a bit before the brass is pushed back.