Soft primers falsely show cratering/pressure signs?

[feedr]

Hi guys,

Just wondering this...

So one of the signs of possible over pressure in a cartridge is primer cratering, and there are 'harder' and 'softer' primers.

Is it possible for softer primers to give false signs of over pressure by cratering where a harder primer wouldn't?

[Lorgar]

I think you'd have to be on the border of potential pressure issues for the situation you've described to present itself.

There are harder and softer ones, but it's not like some are butter-soft lead and others are hardened boron steel.

[Granting]

Don't forget cratering isn't the only indicator that you could have a pressure issue.

Pierced primers, flattened ones, hard extraction and the list goes on.

I know you said you're not having any issues now, just stuff to keep in mind for the future if you get further into it.

[Herdsman]

There are harder and softer ones, but it's not like some are butter-soft lead and others are hardened boron steel.

Yup.

If you do have a primer crater down the road I wouldn't dismiss it as "oh, well these primers are soft ones, that'll be it."

Plenty of other signs to check as well as cratering.

[Aster]

I suppose it's possible.

As outlined above though, if you're asking this with a view to pushing the envelope in reloading in the future, there are plenty of other signs you should be paying closer attention to.

[Hardcast]

I think it's a valid point that's been made here,

I recently aquired through an Estate sale, a number of Lge pistol primers, which I intend to use in my reduced rifle loads.
Haven't seen an issue yet, but would go litely if testing with more standard loads.
I don't recall ever having a problem with the .222 or .223, with Win., pistol primers way back when I started reloading, but
I never load hot.

[Prios]

I don't recall ever having a problem with the .222 or .223, with Win., pistol primers way back when I started reloading, but I never load hot.

Bit off topic here, but along those lines...

Are the ever over pressure signs with rimfire and the smallest calibres?

Can a .17 or .22 have load pressure issues or is it just once you started getting heavier bullets in CF loads?

[feedr]

I never load hot.

Me neither. I haven't had any signs with trying a couple of different primers now anyway so it's all good.

[Apollo]

Primers cratering is not always a sign of pressure problems.

There are a number of issues that can cause primer cratering like bolt firing pin hole to firing pin clearance, heavy firing pin spring, primers not seated correctly, excessive bolt headspace, soft primer cups and hot loads to name just a few. Lots of others things to look at before one thinks over pressure loads or even loads getting to that stage.

Measuring cartridge cases over their body with an accurate micrometer is another way to keep an eye on pressure signs and if a case is difficult to eject or load then it may be showing pressure signs before a hard primer will crater.

High pressure calibres with the wrong primer will not probably show crater signs before it's pierced and you wear the blast and/or damage your bolt face.

Here is a link to some primer case measurements, especially in Small Rifle Primers you will probably get the idea. Remington 7 1/2 are thick and also quite hard but can even cause problems not igniting if your firing pin strike is on the light side.

http://www.jamescalhoon.com/primers_and_pressure.php

Calibres like .204 Ruger, 6.5x47 Lapua and a few are considered High Pressure Calibres. If you use a standard soft primer in a .204R you are asking for trouble and it won't be long before you see a pierced primer during load development.

[Warrigul]

Primers cratering is not always a sign of pressure problems.

There are a number of issues that can cause primer cratering like bolt firing pin hole to firing pin clearance, heavy firing pin spring, excessive bolt headspace, soft primer cups and hot loads to name just a few. Lots of others things to look at before one thinks over pressure loads or even loads getting to that stage.

Cratering is the primer being raised above the normal level around the pin indentation,

A heavy firing pin spring shouldn't be a problem, it is excessive firing pin protrusion or a sharp pin from erosion- not excessive spring force that causes a pin to punch straight through a primer. Centerfire firing pins have a positive stop within the bolt.

Springs that are too light or worn can allow the primer face to climb in the channel a bit especially if there is excessive pin to bolt clearance.

Excess headspace can cause the primer to back out of the case but usually not crater.

I have found CCI BR4 benchrest primers to be a more solid primer.

Just my opinions.