primer testing

[gem308]

I recently read an article about a shooter who tested the power of various brands of primers using a swinging metal plate to measure the amount each brand of primers would move the metal plate. I'm trying to find the article and I have been unsuccesful. Have any of you seen the article and if so, what magazine and month?

 

[acloco]

Did not see this, would find it interesting as well.

Of note, I do have 5 rounds with the exact same powder/charge, same bullet, & same case...loaded with 5 flavors of primers. Will provide the results from the chronograph when I go to the range again.

 

[acloco]

Used the standard, small rifle Win primer for a sighting shot. The results of 4 other primers, using same headstamped cases, and the exact same powder charge,Acculab scale) as follows:

CCI450 3546.8
Rem 6.5 3557.1
Fed 205 3488.6
Fed 205M 3506.3

Shot over a Pact chronograph with a 14 foot distance to the first skyscreen. These were shot out of a 28" PacNor barrel chambered in 223AI.

 

[gem308]

Thats a significant difference and shows why when we end up with a good load, it pays to go back and work up to the same load with different primers. I suspect this not only holds true for velocity but for accuracy as well. Thanks for making your results available.

 

[Spotcheck_Billy]

Acloco,
Thanks for the info, but I believe ES and especially SD figures are more important when testing primers. Do you have those numbers and can you post them?

 

[acloco]

No, I loaded the primers with a varmint load that I worked up for my 223AI. This load is well under max for my rifle, so I knew that I would not have a problem with substituting primers.

I have worked up loads with all of these primers and usually end up with an ES of 20-40 and SD of 10 or lower.

Just wanted to post some info that there IS a difference in primers and reloaders SHOULD work up every load.

 

[tailgunner]

I remember reading the same test and I thought it was on or linked to Dan Newberry's Optimal Charge page. I just looked but didn't see it.
I did find this tho...

http://www.the-long-family.com/primer_study.htm

EDIT:

I found a copy I printed out,I never throw ANYthing away) and the link was:

www.castingstuff.com/primer_testing_reference.htm

 

[gem308]

That's the one. Thanks very much for sending it. There some surprises here and thats what I wanted to look at. It won't change how I test primers but it is another test to add to the stack.
Do you remember where this came from?

 

[RoyinNC]

The sample above has an ES of only 68.5 fps and you said the load normally gives an ES of up to 40 fps with the same primer. Thus, you really told us next to nothing.

 

[acloco]

Roy - these are varmint loads, directly thrown from a RCBS Uniflow, spot checking every 5th/6th case...an ES of 20-40 is sublime. Did not add that caveat..and I should have.

 

[RoyinNC]

I understand, but the reality is that the velocity numbers could have been nearly the same if you were shooting the same primer brand for all 4 shots. I just hate to see people trying to draw conclusions from this data, which is much too limited to be meaningful. I applaud your effort for trying to do some testing, but make sure you are putting enough effort into it to assure useful results.

 

[acloco]

I understand what you are stating.

Round counts in the last two years include:

2500 in 17 Remington
3500 in 204
6000 in 223
500 in 223 AI

80% of the rounds were shot in the field, at 80 degrees F or better.

Remaining 20% were shot during load work up of a multitude of powders, bullets, and primers. My current powder inventory includes 32 different powders...from IMR, AA, Viht, Hodgdon, Win, etc, etc. Current bullet inventory...ugh...shudder to think. Current primer inventory is being widdled down to CCI 450 and Federal 205 & 205 M.

Not a lot of rounds shot for some people, but on the other hand, a LOT of rounds compared to others.

The "primer testing" that I conducted included the same lot/headstamp of brass, same lot of bullets, same lot of powder, and 4 different primers. The loads were measured on an Acculab...it does measure one kernel of powder.

The chrono is a Pact.

I am not sure what you are a looking for, but I controlled as many variables as possible.

My point in posting the info...there IS a difference in primers.

 

[RoyinNC]

You missed the point completely. I give up....

 

[acloco]

You missed the point completely. I give up....

I believe you are reading or trying to read something into the data I gave.

Simply put...4 exactly measured amounts of powder, in 4 cases with the same head stamp, lot number, using 4 bullets from the same lot/box of bullets, fired from the same rifle, and over the same chronograph, on the same day....provided 4 DIFFERENT velocities from 4 DIFFERENT primer manufacturers.

Plainly - there IS a difference in primers.

 

[acloco]

If the SAME primers were used...then there IS a problem in the reloading process...with that much velocity difference.

 

[tuck2]

If the primer test used five rounds with the same primer and then giveing the average ft/sec velocity of the five rounds the date would be meaningfull . The test then would take fireing twenty rounds.

 

[robbor]

I saw one also, It showed that fed match was the best. Its a good thing because that is all I use and have no plans of changing.