Thread: So how much difference does the primer make?

So I stuffed up and primed some cases with Federal 210s instead of the CCI 200s I use in that calibre and have just finished load development with. I realised my mistake straight away, so started again from scratch for my developed load.
Being a Kiwi of Scottish descent I didn't want to waste 14 primers so loaded those cases up with a starting load to use as plinkers, barrel foulers etc.
Does anyone have any info on how much effect make of primer has on pressure or velocity?
I realise Federal primers are considered softer than most, so i wanted to play it safe. The load used is 2 grains lower than my developed load and 3 grains lower than I have tested with no pressure signs.

sub 150 yards...hohum no bother...unless you put a hotter primer in a maximum load you will be fine.
the animal you shoot wont care.

it does make a big difference with shotgun loads as far as pressure goes,rifle loads not so much,unless you up close to maximum.

i know they dont work to well if you put them in backwards

Ha ha, I have a few 223 cases with the primer in sideways that I don't know what to do with!

me being me i just put some muffs and glasses on and they came out without going off i even reused them and they worked

Am not sure how others do it but have worked out that priming before you put powder in saves a lot of mess.

Originally Posted by Cigar

Ha ha, I have a few 223 cases with the primer in sideways that I don't know what to do with!

Reading that causes me concern, that’s a sign that there’s a little too much haste or not quite enough care when installing the primers

Please don’t take my comments as a criticism, just wanting to point that out

If you are using any type of hand held priming tool then Google “ primer installation proximity detonation”

It occurs when a jammed/ mis oriented primer goes off violently and sets all his mates off in the hand held primer tray

The pictures show multiple fingernails missing and a lot if not all skin missing off fingers and palms etc

Please be careful with primers, they are the most violent of things when upset.

Andrew R

Originally Posted by 7mmsaum

Reading that causes me concern, that’s a sign that there’s a little too much haste or not quite enough care when installing the primers

Please don’t take my comments as a criticism, just wanting to point that out

If you are using any type of hand held priming tool then Google “ primer installation proximity detonation”

It occurs when a jammed/ mis oriented primer goes off violently and sets all his mates off in the hand held primer tray

The pictures show multiple fingernails missing and a lot if not all skin missing off fingers and palms etc

Please be careful with primers, they are the most violent of things when upset.

Andrew R

Yes, not enough care and poor technique on my part when using a hand priming tool.
I have a healthy respect for primers after firing a primed case in my 223 about twenty years ago and seeing the scorch marks left on the wooden floor. Which is why the two or three sideways primed cases have been sitting in the cupboard for the last couple of years (I’m too chicken to try and remove the primers)

I had this once. I eased it out with a universal depriming die. Just went very gently and slowly. I have a few damaged primers stored in an old pill container and soaking in ballistol. Will bury them I guess.

Originally Posted by Cigar

So I stuffed up and primed some cases with Federal 210s instead of the CCI 200s I use in that calibre and have just finished load development with. I realised my mistake straight away, so started again from scratch for my developed load.
Being a Kiwi of Scottish descent I didn't want to waste 14 primers so loaded those cases up with a starting load to use as plinkers, barrel foulers etc.
Does anyone have any info on how much effect make of primer has on pressure or velocity?
I realise Federal primers are considered softer than most, so i wanted to play it safe. The load used is 2 grains lower than my developed load and 3 grains lower than I have tested with no pressure signs.

Short answer it wont make any difference a long as they are std or match primers.
Magnum primers are actually less brisant ( the technical term for the detonation characteristics of an explosive) they produce the same amount of energy but over a longer period ie a longer burn time. The reasoning being ball and heavily retardent coated extruded powders used in high capacity magnum cases dont always ignite in a repeatable fashion with a short sharp thump and need a bit more encouragement.
With faster powders you reportedly do get more velocity and pressure spikes as the initial ignition phase starts with more powder burning.
I understand that in sub zero temperatures magnum primers give more consistent ignition and velocity than std ones which kind of makes sense,
As someone who isn't primarily long range target shooter and is a bit of a scrounger I have never noticed any difference between standard primer brands including match primers that couldn't be accounted for by operator error when shooting out to 500 meters which is the "limit of my competence" so to speak especially on game.

Ive never found ive had to rezero a rifle after changing primers

I have a reloading manual "Any shot you want" by A Square and has a lot of good info. One section they compare various primers of the same size ( eg Standard ,etc). the results showed that there was a difference in the pressure between different primers.
I have never worried to much about it especially in my early days of loading, these days I try to stick to the same brands. I haven't noticed a difference in points of impact when using different primers.

It caused a old friend of mine to miss a deer

took him a while to find the fault as this was his go to rifle but he found it in the end

I have tried changing primers with the same load and had the same POI so I havent seen the issue yet

Might he not have simply missed, it happens you know and theres no shame in admitting it.

Take a "known" load and change the primer. Chrony and shoot on paper.....can be some suprises. As in speed and group size.