Primers

[ilikespeed]

Which are the hottest? I looked most of the morning and found several lists, problem is they are all different. One listed Rem 7 1/2 as the hottest and the other said it was at the other end. Anybody know for certain. Rifle primers only please.

[Bill K]

The magnum primers are the one's that give off the hottest and longest flame/temp. Rem 71/2, bench rest and the mag style also have the thicker cups, to stop piercing of the primers. Go with Rem 7 1/2 or Fed 205M for small rifle and hot flame. That is my opinion. Bill K

[ilikespeed]

Thanks Bill. but I was hoping for more.
I have been reloading for a long time and know about thicker cups, etc. and that some primers are 'labeled' magnums. But does someone have info where a true scientific test was done to prove how hot the spark is from each? For example, CCI's magnum primer may be hotter than their non-magnum but is it truly hotter than a non-magnum primer from another manufacturer.
By scientific I mean by someone such as Sierra Bullet Co. I saw a test where someone loaded several rounds and everything was the same but the primers. He chronographed each shot and concluded that the fastest one had the hottest primer. This does not sound totally wrong, however with my limited knowledge in this area I wonder if the powder used, barrel length, cartidge, all could possibly come into play and if changing 1 of these would change the results.

[Jim White]

The magnum primers are the one's that give off the hottest and longest flame/temp. Rem 71/2, bench rest and the mag style also have the thicker cups, to stop piercing of the primers. Go with Rem 7 1/2 or Fed 205M for small rifle and hot flame. That is my opinion. Bill K

How does the CCI BR's stack up to these two?

[Bill K]

From what I have read, and I wish I could locate a article re. the flame ambiance on various primers, the bench rest and mag primers all have very simular flash points/amount of flame. I know there are some good articles and studies on them. I believe a back issue of Varmint Hunter Magazine had a article on primers.. Maybe a person could email and ask them which copy, back issue it was and obtain one. Bill K

[jlc204]

see this link

http://www.6mmbr.com/primerpix.html

[jrwoitalla]

Just wondering, what will you do with the info.? I use #71/2's for my 204, but prefer 400's for my 223cal and 221fireball as they give better accuracy. Interesting how that works. Hotter may give more velocity, but not always better accuracy-in my experience.

[Bill K]

see this link

http://www.6mmbr.com/primerpix.html

This is along the lines of what I was talking about. Nice photos and info. I know there are others out there with even more, but this should help some see the difference.. I have just about settled on Rem 7.5's in all my small rifle cases. And the large rifle mags in the big guns. It just works best for me, in my loads. Bill K

[K22]

see this link

http://www.6mmbr.com/primerpix.html

This is along the lines of what I was talking about. Nice photos and info. I know there are others out there with even more, but this should help some see the difference.. I have just about settled on Rem 7.5's in all my small rifle cases. And the large rifle mags in the big guns. It just works best for me, in my loads. Bill K

I have also done the same thing.

[Bill K]

Which are the hottest? I looked most of the morning and found several lists, problem is they are all different. One listed Rem 7 1/2 as the hottest and the other said it was at the other end. Anybody know for certain. Rifle primers only please.

If you would like a little insight, along with the post showing the flash above, get a copy of the May/June 2012 Rifleshooter magazine and read Layne Simpson's article "A primer primer" on page 20. Gives some good info as to use and when and where on a couple brands. Bill K

[Jim White]

Which are the hottest? I looked most of the morning and found several lists, problem is they are all different. One listed Rem 7 1/2 as the hottest and the other said it was at the other end. Anybody know for certain. Rifle primers only please.

If you would like a little insight, along with the post showing the flash above, get a copy of the May/June 2012 Rifleshooter magazine and read Layne Simpson's article "A primer primer" on page 20. Gives some good info as to use and when and where on a couple brands. Bill K

To say the Remington primers "lights a fire under it" is a understatement.

[Wrangler John]

In the old days I found that Remington primers were the most accurate across the board. In those days the primers were manufactured under the Remington DuPont label by Remington Arms Co. Inc.. All Remington primers were manufactured with two leg anvils. I found two samples of the old two legged primers in my paleo-loading collection, see below:



The original two leg anvil packaging made much of the fact that, "the priming mixture is at exactly the right distance from the flash hole ensuring a uniform flash." I had only my empirical evidence to go on, but suspected that the two leg anvil made it more stable and less prone to flexing under the firing pin strike. I won't get into the actual area of the two versus three flash ports. This observation held for thousands of rounds of various centerfire cartridges from .221 Fireball to the .45-70. Today Remington primers are manufactured with the same three leg anvils as all the rest. I am uncertain if Remington is actually manufacturing their primers or subcontracting. At one time there were 6-1/2, 7-1/2 and 7-1/2 BR small rifle primers, 9-1/2 and 9-1/2 Magnum large rifle primers. Some wags say that the 6-1/2 was used in older lever action cartridges or those using a small rifle primer, the 7-1/2 for .222 Remington and later higher pressure cartridges. The 7-1/2 came into its own with the development of the AR-15 and the 5.56 NATO and .223 Remington cartridges.

In choosing a primer, the neat photos of flame brilliance and length are deceiving and counterproductive in that these factors do not necessarily translate into which will be most accurate in any given cartridge and rifle. Some claim that too much brisance in a primer will drive the bullet forward from the case before the powder charge ignites, causing a few micro-seconds of movement-pause-movement in the bullet which results in inaccuracy. This was said to be a problem in the .22 Hornet, while a milder primer produces a smoother ignition cycle and better accuracy. This may be the reason that magnum handgun loads, especially in large bore revolvers and heavily coated ball powders, develop maximum accuracy with a heavy crimp that delays bullet movement until the powder charge is full alight.

I have read that a certain ammunition manufacturer uses Winchester primers to develop all their loading data because the Winchester priming mix is less sensitive to temperature variation.

It is always wise to follow primer recommendations mentioned in loading data, especially where magnum strength primers are recommended for use with large charges or ball powders. It may be necessary to develop a load with several samples of different brands of primers, as accuracy can change with cup hardness and thickness, firing pin protrusion, headspace consistency, powder brand, bullet type, neck pull and ambient temperature among the factors. That's what I find so cool about loading - it really taxes the mind.

[inKYfromSD]

Wrangler John, thanks for the info. I always though the pictures of flaming primers was completely subjective. I've not seen any tests that involved pressure from fired primers. Someone told me long ago to use magnum primers in rounds that were going to be fired during chilly South Dakota winters. .204 Ruger rounds loaded with Rem 7 1/2 primers seem to be more consistent than with CCI 450, all else being equal. I've not done a blind test, I knew which rounds were loaded with which primer. Might be a good comparison to do this weekend.

Cool old boxes. You don't have any powder in small wooden barrels do you?