Deep primer pocket

[NW Sportsman]

Hi there!
I bought some Norma brass a while back loaded them up and noticed my CCI large magnum primers were more deep seated than the other brass I have and are out of range of my Benelli R1 in .300 Winchester mag firing pin.
I emailed Norma about this but haven't heard anything back from their tech department.
I use a RCBS hand held primer tool and was thinking of building a stop that will not seat the primer so deeply.
Any thoughts?
Thanks in advance,

 

[L.Sherm]

If they are to deep send them back, depending on how tight the pockets are when the firing pin strikes them could push them deeper and have misfires.

 

[jimbires]

the primer needs to be bottomed in the pocket . if not the firing pin can drive the primer deeper and cause misfire .

 

[L.Sherm]

What is your firing pin protrusion?

 

[NW Sportsman]

What is your firing pin protrusion?

Not sure I'll have to measure

 

[NW Sportsman]

Not sure I'll have to measure

I haven't measured firing pin projection but factory ammo and other hand loaded ammo that aren't Norma do just fine. Using this as a go/no go gauge the difference is about 1/64"

 

[L.Sherm]

Your protrusion should be in the neighborhood of .055.
I had some BR4's years back that would misfire about 4 out of 10 switched to rem 7.5 cured the problem.
Sometimes different primer, brass, firing pin combo dont work.
Measure the thickness of your primers also they should be .118 and try to get an avg on your primer pocket depth and protrusion so if you have to send the brass back you can have the measurements to back up that the pockets are to deep

 

[NW Sportsman]

Thanks for the help.
enjoy your day.

 

[243winxb]

The depth of pockets can be measured with an RCBS dial vernier caliper.
Primers can be below the case head by .008"

The firing pin will reach the primer at .055" protrusion.

 

[jdyoung]

You can make a gauge as in the 1st picture to judge protrusion with a file , calipers, and some flat stock, ( brass or steel, even aluminum). The one pictured is for sale at Brownells if you want to go that way.

BROWNELLS FIRING PIN PROTRUSION GAUGE | Brownells


Or Brownells sells a more elaborate gauge that records protrusion and is then measured with calipers.

BROWNELLS CENTERFIRE/RIMFIRE FIRING PIN PROTRUSION GAUGE | Brownells

 

[MagnumManiac]

Interesting, numbers thrown about but no ACTUAL measurements.
Measure the depth of the pocket, seat a primer as far as your tool will seat it, punch it out (carefully) and measure it, then measure a new unseated primer, compare the measurements. Measure the pin protrusion on your bolt.
All measurements on primers need to be taken and compared with a seated primer that has the anvil flush with the cup and NO crush. Then you can determine depth below flush required and the amount of crush or pre-tension. I like .003"-.004" of crush AFTER the cup and anvil are flush with the pocket bottom.
Primers NEED this tension to perform correctly, if seated high and without crush, the energy from the firing pin is used to seat the primer deeper and/or crush the cup against the anvil further. This causes erratic ignition.
I have even seen Eric Cortina take zero notice of how he was priming cases. If it goes bang, then all good??
Not for me, the primer is where it's at, it governs HOW your load is going to work and even the type needs to be tested when developing loads.

Cheers.

 

[NW Sportsman]

Thanks folks! It sounds to me that this brass is manufactured incorrectly & no way to correct this problem.
The rounds that I have loaded will be disassembled and the brass disposed of.
I bought this brass sometime ago so I can't return it to the vendor.
I may see if I can send it back to Norma but shipping to Sweden may not be worth the trouble or cost.
In the future, I will inspect the cases closer that I buy, no matter the vendor.
The one thing that I have noticed is buying large magnum primers, .300 Win mag brass and factory rounds is getting difficult.
I've got about 3 to 4 hundred cases so I can load up and get my rifle ready for hopefully a spring bear draw hunt in north eastern Washington this year.
Take care all and happy shooting.

 

[MagnumManiac]

My biggest issue with Norma brass is how tight their primer pockets are.
No matter what case I buy, the pockets are always tight.
Have the same issue with recent lots of SR Lapua brass in 6.5x47 and 22-250.

Cheers.

 

[MagnumManiac]

Duplicate.