Primers

[kstrick]

Does anyone know of any studies / experiments where the gun, bullet, powder and load were the same but different primers were used?
Was there a difference in velocity or accuracy?
It would also be interesting to see the difference in velocity and accuracy using the same scenario when temperature and altitude is a variable as well.

Thanks
Ken

 

[RT2506]

I don't know of but one printed study that was in a gun magazine a few years ago that I remember seeing but I have run my own. You will see some velocity change and accuracy with some primers is better than with others.

 

[johnnyk]

kstrick,
I did an informal test back in July of 2002 using my 7Mag Sendero and the Sierra 160gn GK. The powder of choice was RL19, with loads tested at 61, 62 and 63gn's. The OAL for all was 3.2645". I didn't take very good notes back then and don't have any special notes on the velocity other than it averaged 2751fps for all loads tried. I used Rem 9.5M and CCI BR2 primers. The 9.5M's all produced groups under 1MOA (.6-.9") and the CCI's were all over 1MOA (1.1-1.5"). Pretty uninformative as scientific data goes but I just did it to see if the primers make a difference. They do.
Check this out; (Primer Testing Reference). JohnnyK.

 

[kstrick]

Thanks guys,
I am going to do some of my own informal testing myself.
I will post my results asap.
I will use a Rem .308, Ruger .300 WSM and a Rem .243

 

[tlk]

Why does it make a difference?

Loaded a large rifle primer on an empty case once upon a time and shot it to see the strength - flame came out out of the 20" barrel quite forcefully. If they all do this (assuming they all do), why would it make a bit of difference? Is it due to the force of the explosion, length of time of the primer explosion (more powder burning at once), or what?

In an odd kind of way, to me this is the same as asking how a difference in caps would change a shot from a percussion rifle. If it shoots flame, I assume we would be good to go.

I don't doubt it makes a difference, I just dont get it.

 

[overbore]

I have done two posts on primers; suggest you use them as your testing starting point. Best wishes, Overbore

 

[30-06 boy]

gun)kstrick,
i had the same question a while back,i found some info on the web. cant remember where though. anyway here it is.

cci200=mildest standard large rifle
wlr=hotest " " "
rem9 1/2=mildest magnum large rifle
wlrm=hotest " " "

the test below bullet/powder/charge/brass did not change, just primers

7rm/160spbt/66 h4831/win brass

winchester wlrm/3045fps/67600psi
winchester wlr/3024fps/64400psi
federal 215m/3036fps/61400fps
cci 250m/3039fps/61500psi
remington 9.5/3041fps/59300psi
cci 200/3011fps/54800psi

hope this helps,jason

 

[overbore]

Just as a polite reminder, the primer best for you depends upon how many shots you will fire--save the flames- if for example you are shooting at a match with more than one shot--- you need a primer that will contribute to the lowest SD by having the lowest ES which, unfortunately is not the CCI even though I use them. There are two milder and more consistant--. For the hunter, find out what your smallest group is, by component selection and seating depth changes, and hope or practice, your choice, that your cheek weld, sight picture, trigger release and hold are constant enough to replicate the testing shots you did.

Overbore

 

[BountyHunter]

I seen other primer tests that show pretty much the same thing that Jason (30'06 Boy) shows.

The same load gave a 13,000 PSI difference with just primer changes. that is something none of the ballistic programs compensate for such as Quick Load. That is why you always start low and come up, particularily with a load off the internet or from your buddy. At least most of the reloading manuals show you what primer they used.

That is also why "definitive" pressure test results from a ballistics program or out of a manual are not accurate and anyone who relies on them is asking for trouble.

BH

 

[overbore]

Bounty Hunter,
We are in agreement and since we both are seniors in the reloading sport, I will postulate my personal findings which are "that the milder the primer, such as Wolf and CCI, the lower the pressure" but then again you and I know that moly, bullet dimensions vs bore dimensions, case capacity, ambient conditions, barrel temp, chamber shape and dimensions et,, etc. all influence chamber pressures. My son is in the four shots per year - max hunting - four kills per year category - not counting his pheasant bags, while I can no longer walk the miles or climb the hills required in hunting so I shoot more long range and target rounds and have over the years developed certain narrow comfort zones for my loads. When any component changes,I loose my comfort. Overbore

 

[avalauncher]

There is an in-depth study of how each of the individual components (brass, powder, bullet, primer) relate to accuracy in the most recent copy of Handloader Magazine (Dec-Jan 2009). The writer did tests keeping all components the same except one and reported his findings. Very interesting article. I believe, for him, he found the CCI 250's the most accurate.

As a Weatherby shooter, I found his findings on primers, bullets and brass very interesting. Since he was using a .308 which uses faster powder than would appropriate for the magnum's, that part of the study was of no use to me.

 

[kstrick]

Thanks...I will get a copy asap
Ken

 

[BHP9]

There is an in-depth study of how each of the individual components (brass, powder, bullet, primer) relate to accuracy in the most recent copy of Handloader Magazine (Dec-Jan 2009). The writer did tests keeping all components the same except one and reported his findings. Very interesting article. I believe, for him, he found the CCI 250's the most accurate.

As a Weatherby shooter, I found his findings on primers, bullets and brass very interesting. Since he was using a .308 which uses faster powder than would appropriate for the magnum's, that part of the study was of no use to me.

You beat me to it. All OK.

The article is on developing the most accurate .308Win load.