Light primer strike or bad primer

S

Stats Shooter

New member
I have had 5 FTF's from the same lot of primers. I am thinking it is the fault of the primers but I'm not 100% sure. I am attaching some pictures. What do y'all think?





 
Last edited by a moderator:
Doesn't look like a light primer strike to me. How old were the primers and what brand?


Sent from my iPhone using Tapatalk
 
I'm not sure the actual age, but I bought them 2 yrs ago, stored in climate controlled room. Cci-250


Oh and obviously I checked to ensure they had powder....I pulled the bullets. and the primers were seated properly, 0.006-0.0085 using my RCBS auto bench primer.
 
Looks like a good primer strike so it's hard to say at this point, but the usual culprit is insufficient seating depth. However I've really never known the RCBS auto to fail like that. But did you try firing them a second time? If they did fire on the second try, that would tend to support the insufficient seating depth possibility. But I don't want to blame the RCBS tool since it is certainly my favorite. Keep trying and report back!!
 
In response to the last post, on a couple of them I did try to fire them again and nothing happened.

I then removed the struck primer on them and on my shop floor I hit them with a hammer...Took two whacks but they went off.

It's puzzeling. Usually high primers or a bad firing pin results in more regular FTF'S than 5/700. I have never had this issue before in this gun, and never with my RCBS auto primer. Unless the pockets on this brass are just too deep it MUST be the primer right?

But if the pockets were too deep would the strike not appear light?
 
You could measure the primer cup depth to determine if the misfire case depths might be excessive. Your cases are .300 Win Mag and by way of comparison, a Hornady once fired case and deprimed measured at .130. Clean the primer pocket first since the residue can account for .002 or so. And of course CCI primers are generally close to the top in the hardness category. So right now I wouldn't know whether to put my money on bad primers or insufficient primer seating depth. But measure the actual primer pocket depth, probably just to rule that out.
 
. Your cases are .300 Win Mag and by way of comparison, a Hornady once fired case and deprimed measured at .130. Clean the primer pocket first since the residue can account for .002
Click to expand...


Hello and thank you for your reply.

I tumble all my brass in a wet stainless steel pin tumbler which cleans the primer pockets so they look factory new.
The primer pocket depth in all the Norma brass is 0.1275-0.1280" deep, including the misfires.

I forgot to mention two critical bits of information, sorry.

I forgot to mention this happened in my Remington brass also, but same rifle. And, I have had at least 1 hangfire where I heard "click" and then a split second later "bang" in the Norma Brass.
 
OK, that additional information helps some. I'm putting my money on bad primers. That happens; I once had an entire carton of 1000 large rifle Remington primers replaced--misfires and hang fires.

Convincing factors are 1) primer pocket depth good, 2) RCBS auto prime tool in use for proper seating depth, 3) happening with other brass, 4) occurring with rifle you are obviously attuned to, and 5) hang fires in addition to misfires.
 
Last edited:
Yea, the primers being the issue is the direction I was leaning. But it's always a good idea to have a fresh set of eyes look at a problem.

When there is a problem, I typically look at myself first and try and see if there is something I did wrong. I have NEVER had an issue with CCI primers before this, and I have used tens of thousands of them. I only have 200 left of this lot so I'm not going to bother trying to exchange them. I'll just use them up in my target rifle for fouling loads and pre competition zeros since their velocity is almost identical to my other lot of 5000 (<= 2 fps)


As an aside, the only other time I have ever had an issue with primers is when I was new to reloading and tried using a set of Lee universal shell holders in my RCBS hand priming tool. The shell holder bases by Lee were too tall and the primers didn't seat all the way down in several cases. I had to use my rock chucker press priming arm to fix them all. But after I went and bought RCBS shell holders for all my cartridges as an RCBS rep suggested, everything worked fine.

I also have Redding shell holders which work fine also, but I do not use Lee shell holders anymore.
 
Last edited:
I agree it sounds like primers.

I have had issues with case pockets not formed properly. I always feel the case head to primer high with my finger. It's a simple seating inspection. If the primer is too high or to low I can feel it. Then you can measure to make sure. Although once you fire the round that changes.

By purchasing a Redding primer pocket uniformer. You can true diameter and depth of your primer pockets when you receive them. It will resolve seating problems such as hard to seat primers and primers not seated fully.

In a few cases the primers in my 44 Mag. were not seated fully.
I had planed to hunt with the pistol and at the last minute I found the primer fouled the pistol frame and stopping the cylinder from rotating.

Other times I deformed primers in the pocket trying to fully seat below the head stamp.

Keep your primers dry and cool. Out of the weather Buy them fresh not handed down not knowing how they were handled. I have a few primers 30> years old and have not had a bad one yet.
 
Last edited:
What do y'all think?
Click to expand...

I am sure you furnished all the information like make, model and brand, I am the only one with killer firing pins but when my firing pin hits the primer the firing pins crush the primer.

And then there are reloaders that assume the extractor jumps the rim, if the extractor does not jump the rim the case head is held off of the bolt face. There is the chance the primers is busted, when that happens the rim jumps the extractor; problem, case head separation.

And then there were a few mistakes made when adding a Timney trigger, the firing pin travel was reduced.

F. Guffey
 
You mentioned seating "0.006-0.0085". I don't know if you mean the amount below flush with the case head or the amount of reconsolidation (squeezing of the primer mix by the anvil during seating). -0.004" below flush for the finished job, and -0.003 of anvil compression into the priming mix are more normal numbers. A lot of primer pockets I've measured are closer to -0.130" deep, so between that number and the shallower pockets you seem to have, you may be crushing the primers hard enough that a few underwent parting of the priming mix at the bottom of the cup from the anvil poking down too far.

The way to check this out is to measure some of the primers for total height. Subtract that height from the depth of the primer pockets, then subtract an additional 0.003. The result will be how far below flush with the head you want the seated primers to be with these primer pockets.
 
This thread got me thinking about how deep primers are seated in Federal cases after using the Redding primer pocket uniformer tool for '06 M-1 Garand ammunition. Measuring some loaded rounds kind of got my attention! With CCI primers most were between .004 and .008 below flush and some that I won't even mention. But I've never had a single misfire, thanks perhaps to the floating firing pin really stretching out. I don't use the uniformer for '06 bolt rifles or any other rifle or caliber. Three M-1s seem to really eat up and like the ammunition regardless of primer seating depth. The deep seated primers may be good protection against slams.

Then checking the Federal American Eagle factory M-1 ammunition, the primer seating depth was .004 to .005 below flush. So at least some of mine conform to standards after using the uniformer.
 
Last edited:
You must log in or register to reply here.
Back
Top