Bad batch of CCI large rifle magnum primers

[ZaneV]

I just loaded 20 rounds of 416 rem mag for my new model 70 safari express and had 3 fail to fire, attempted to fire each 5 times with no luck. Pulled bullets, verified correct powder charge, primers sit 0.007-0.008” below flush of the case head and are dented, firing pin protrusion is 0.055”. I’ve never had a bad cci primer, so i carefully deprimed and loaded the same primers into a 6.5 creedmoor case (primer only, No bullet or powder) and attempted to pop the primer and still nothing, primer looks brand new aside from the dent from the firing pin. So I think I can rule out any issue with the gun at this point. Any one else have issues with cci LRM primers? Attached picture of primer after depriming.

 

[fourfive8]

If the priming compound pellet looks normal and the anvil is in place… about the most likely thing would be contamination of the pellet. But who knows?

 

[pilar]

I have had some bad luck with primers post pandemic, I usually consider factory loaded ammunition 100% , but have had multiple instances with different types and brand since 2021 with dry strikes ( I even considered going to a gunsmith with one rifle but changed to a different lot # of ammunition and problems solved)

 

[Wyatt Smith]

Try a new firing pin spring. It’s pretty common to get light strikes with the new M70s.

 

[375er]

I have a batch that I have had for years that is bad to the point I won't use them even for the range. Keep meaning to destroy them.

 

[GuttormG]

The Norwegian Rifle Association (which also sells ammunition and reloading components) a few years ago had a large batch of CCI-200 primers with a failure rate that was extremely high.

Even the best companies can make mistakes.

 

[mitch4570]

I left a post earlier about CCI primers. Bought them because it's hard to find magnum primers and it was all I could find at the time. Loaded a few rounds 10 or 20 had 3 missfires. Dinally got wwm and federal 215's and no problems. Now I have 2000 useless CCI primers.

 

[ZaneV]

Try a new firing pin spring. It’s pretty common to get light strikes with the new M70s.

You were right on the money, the stock spring was only measuring 20lbs cocked which is pretty borderline IMO when most rifles use a 24-25lb spring. There’s no high pressure springs available through anyone yet, and I really didn’t want another stock spring, so I did some research and found where a guy modified a Model 700 short action firing pin spring to work. My dad had a stock one laying around (I added a post in the gunsmithing section going into more detail) and after being modified I came out with 23.5 lbs of pressure and it also corrected the sight bulge the stock spring had that resulted in rubbing the inside of the bolt (also hindering the firing pin). Before and after pics of primers strikes.

 

[Wyatt Smith]

You were right on the money, the stock spring was only measuring 20lbs cocked which is pretty borderline IMO when most rifles use a 24-25lb spring. There’s no high pressure springs available through anyone yet, and I really didn’t want another stock spring, so I did some research and found where a guy modified a Model 700 short action firing pin spring to work. My dad had a stock one laying around (I added a post in the gunsmithing section going into more detail) and after being modified I came out with 23.5 lbs of pressure and it also corrected the sight bulge the stock spring had that resulted in rubbing the inside of the bolt (also hindering the firing pin). Before and after pics of primers strikes.

I’ll check out your thread. I don’t know why Winchester hasn’t addressed the issue yet. It would be good to know about a good retro fit.

 

[M70375!]

I had the same problem with Remington 9 ½ primers in my model 70 375, I changed firing pin spring and no more problems since

 

[Wyatt Smith]

When mine was causing trouble it was with a certain brand of brass. (Can’t remember now) I tried Winchester Remington and cci primers with about the same effect. A different brand of brass was 100%

 

[fourfive8]

Before pitching primers or chasing different brands of brass or changing firing pin springs or handing over an unknown problem to a gunsmith, always a good idea to uniform the primer pockets of the brass you have. Primers need to bottom out in the pocket with a very slight compression of the pellet. The primer cup needs to also sit slightly below the level of the cases’ base- usually about .005-.007” below. If the primer is not properly bottomed out in the pocket, some firing pin energy is absorbed or wasted upon the strike. All the firing pin energy (force) should be used indenting the cup and compressing /detonating the pellet, not being absorbed by a poorly fitted primer cup.

I use a small end mill tool to ensure proper pocket dimensions and depth. I just finished uniforming the primer pockets of my 577-450 brass. I noticed my current batch of CCI Large Pistol Magnum primers were slightly taller and not fitting as well as my last batch of Federal Large Pistol Magnum primers.