OzFclass

2018-11-26_08-32-33 by James Elphick, on Flickr

CCI450s as seated and after failing to go bang fire forming Dashers. When punched out and given a tap with a hammer they fired. I subsequently found that they would eventually go if fired two or three times...

Well if it was me I would be a bit confused.
The top two show cratering and the bottom two barely show a strike.

Steve,
The top two cases went bang... The bottom two is the result of trying to rely on neck tension and a jammed bullet to hold the case against the bolt face while fireforming to a dasher. This is a headspace issue ONLY..
This would not be an issue if he created a false shoulder in the neck, before fireforming.

Sorry, I made that super confusing, the top two are showing pin strike but failed to fire, the bottom two are as seated (I couldn't see to picture whilst typing)!

The top two are showing very slight cratering and would appear to actually have been fired and went bang. Every time I have had a misfire, the firing pin indentation has had very round edges not the very defined edge like in your photo.
Philip

I am also having troubles with these in my .223, about 1 in ten fails.

Took them home and whacked them with a pin punch, about half of them eventually go off.

Use a different primer type, no misfires.

Josh Cox wrote:I am also having troubles with these in my .223, about 1 in ten fails.

Took them home and whacked them with a pin punch, about half of them eventually go off.

Use a different primer type, no misfires.

Do you full length resize?
Chris

From another forum:
Thomas Gonzalez : A perfect setup on a loaded round ready to fire would be to have no more that 0.001 gap between the shoulder of the loaded round and the shoulder of the chamber. and at least a firing pin with the minimum protrusion, .050 being the minimum and .060 being the max. and an understanding of what max SAAMI spec. primer depth should be to ensure proper ignition. 100% of the people that come to my reloading classes have no idea what SAAMI primer pocket specs are and just arbitrarily cut /uniform primer pockets to whatever depth their purchase tool cuts. Most of you would not consider shooting a firearm with excessive headspace, yet no one worries about excessive primer space. Example: Lets say if you left you primer pockets alone and seated a primer in them and know that was the perfect depth according to SAAMI, and you had a minimum firing pin protrusion of of .050 and only .001 gap at the shoulder of you case. In reality you now have only .049 firing pin fall and now your under what the minimum protrusion spec is! Damn it! Why we hate math right? Now lets say we took this same scenario and cleaned up our primer pockets step back and admire the nice shiny things the have become. Let's say that require .004 to clean them up. Now our minimum firing pin protrusion has become .045, and we wonder why our rifle shoots like ass and why our CCI 450 primers won't go off. It has to be the action makers fault, or time to change my old weak firing pin spring and replace it with a 30 lb. one so it takes a cheater bar to open my bolt when I try to compress it. Nope you may have caused all the issues yourself.

Matt P wrote:From another forum:
Thomas Gonzalez : A perfect setup on a loaded round ready to fire would be to have no more that 0.001 gap between the shoulder of the loaded round and the shoulder of the chamber. and at least a firing pin with the minimum protrusion, .050 being the minimum and .060 being the max. and an understanding of what max SAAMI spec. primer depth should be to ensure proper ignition. 100% of the people that come to my reloading classes have no idea what SAAMI primer pocket specs are and just arbitrarily cut /uniform primer pockets to whatever depth their purchase tool cuts. Most of you would not consider shooting a firearm with excessive headspace, yet no one worries about excessive primer space. Example: Lets say if you left you primer pockets alone and seated a primer in them and know that was the perfect depth according to SAAMI, and you had a minimum firing pin protrusion of of .050 and only .001 gap at the shoulder of you case. In reality you now have only .049 firing pin fall and now your under what the minimum protrusion spec is! Damn it! Why we hate math right? Now lets say we took this same scenario and cleaned up our primer pockets step back and admire the nice shiny things the have become. Let's say that require .004 to clean them up. Now our minimum firing pin protrusion has become .045, and we wonder why our rifle shoots like ass and why our CCI 450 primers won't go off. It has to be the action makers fault, or time to change my old weak firing pin spring and replace it with a 30 lb. one so it takes a cheater bar to open my bolt when I try to compress it. Nope you may have caused all the issues yourself.

Yes Matt that might be so but l adjust my pocket reamer so the primer is 1'' below the surface noting that it's not that easy to measure.

Trevor, 1” below the surface, that’s your problem. You’ve put the primer in the neck. Lol

Trevor Rhodes wrote:

Matt P wrote:From another forum:
Thomas Gonzalez : A perfect setup on a loaded round ready to fire would be to have no more that 0.001 gap between the shoulder of the loaded round and the shoulder of the chamber. and at least a firing pin with the minimum protrusion, .050 being the minimum and .060 being the max. and an understanding of what max SAAMI spec. primer depth should be to ensure proper ignition. 100% of the people that come to my reloading classes have no idea what SAAMI primer pocket specs are and just arbitrarily cut /uniform primer pockets to whatever depth their purchase tool cuts. Most of you would not consider shooting a firearm with excessive headspace, yet no one worries about excessive primer space. Example: Lets say if you left you primer pockets alone and seated a primer in them and know that was the perfect depth according to SAAMI, and you had a minimum firing pin protrusion of of .050 and only .001 gap at the shoulder of you case. In reality you now have only .049 firing pin fall and now your under what the minimum protrusion spec is! Damn it! Why we hate math right? Now lets say we took this same scenario and cleaned up our primer pockets step back and admire the nice shiny things the have become. Let's say that require .004 to clean them up. Now our minimum firing pin protrusion has become .045, and we wonder why our rifle shoots like ass and why our CCI 450 primers won't go off. It has to be the action makers fault, or time to change my old weak firing pin spring and replace it with a 30 lb. one so it takes a cheater bar to open my bolt when I try to compress it. Nope you may have caused all the issues yourself.

Yes Matt that might be so but l adjust my pocket reamer so the primer is 1'' below the surface noting that it's not that easy to measure.

I'm guessing thats .001" below. IME that wouldn't be enough to set the anvil for consistent ignition.' I don't remove any material from my primer pockets and had to adjust to .008" below and then ignition problems went away....cci450s and lapua brass. So I'm guessing if you are removing material you will need to seat even deeper.
I do FLS but I measure every sized case and you can get the odd case that will end up sized .004" - .005" relative to the others that are .0015" - .002".

Rightly or wrongly, I don't touch the pockets and seat the primer so that the seating tool leaves a light, uniform imprint so a slight crush and other than fire forming have never had a problem. I know two people who bought primer seating tools that set the depth the 1st thing both of them experienced was misfires.

Matt P wrote:primers.jpg

So if you have a minimum depth pocket and maximum thickness primer you have to crush 9thou to seat flush or the other worst case max pocket and min primer, you only have 1 thou of crush, to maintain 8 thou below the surface. So I guess that the next logical question is how does potentially having some primers crushed 8 thou and flush and some 1 thou crushed and 8 thou below (worst possible case) affect ES? As I see it, you can work towards maintaining depth or crush but not both so which is better?

I have changed over to Federal gold match primers and bingo no more miss fires.