None, just the little round dent from the firing pin.

yeah mine look nothing like the primer on the left. Mine just has a dent from the firing pin.

If you leave it in factory set up and use heavy loads, sometimes the primers will blow back so hard into the bushing that they get stuck. Take away that slack between the bushing/primer, no bulging or anything like that.

ronlaughlin

Ron the one on the left is what I have seen in other posts quite often, that is why I asked the qestion.

To me that indicates there is a sufficient amount amount of back pressure on the nose of the primer, to push it back into the bushing. Again in my little world that pressure and repeated firing and time would wear on the threads of the bushing if they were loose.

If the 'o' ring is used to absorb the pressure that could and might relieve the wear and tear on the firing pin bushing. So with that in mind increasing the size of the 'o' ring to achieve head spacing as MD is suggesting might work. It certainly is not any less effective than CVA's original design.

The primer on the right is exactly what I might expect from the longer V2 BP,(length and diameter of flame channel increases the volume of gas it can contain and relieves some of the pressure on the nose of the primer). You can still see the beginnings of the impression of the FP hole and the beginnings of the slot in the face of the firing pin bushing on the primer.

Thanks for the pictures... I was trying to dig some up from other web sights....

there wont be pressure once the firing pin is adjusted. The primer on the left gets like that due to it being blow back, basically launched like a projectile.

Ive been shooting 120gr BH209 with a 300gr powerbelt and the primers come out with just the dent. Thought i had some primer pics but i couldnt find anything.

MountainDevil54

I really hope you know enough about the operation of a gun, any gun, to know that there is always pressure on the nose of the primer at the time immediately following the setting off of the charge. Centerfire shooters, reloaders in specific, look for the signs on the primer indicating high pressure. It is statements like this that really makes a knowing person question your credibility.

Anyway, I really believe you are wrong. There will always be blow back pressure on the nose of the primer from the charge going off. There has to be. It really does not matter what the headspace is. Pressure is there and if there is enough it will push the primer into the face of the bolt or frame hard enough to make an impression. Head space has nothing to do with that effect.

There is no difference between the centerfire and a ML in this case.

The amount of the pressure will be detirmined by the size of the charge, the weight of the projectile. the length of the barrel, how tight the projectile is in the bore, and the size of the flash hole. All of these add up to back pressure on the primer.

And even though you might not believe me I hope enough other folks read this and tell you close to the same thing.

I hope this make some sense to you, because ignoring this could get you hurt.

just a misunderstanding at the way i explained it, thats all SL.

Gosh! I hope so..

lol i can promise you, im working in between the web and my mtn stalker with the mag spark and sometimes i just dont go through the details.

That's not true. The primer on the left is the same length after being popped as the one on the right. They both were popped in rifle-breech plug combinations that controlled the expansion of the anvil out of the cup. The primer on the left wasn't launched like a projectile. It was contained in a zero slop headspace environment.

Actually the one on the left was used to fire less powder than the one on the right.