Standard vs Match primers testing

[Kirbydoc]

I think this deserves a different thread.
Apparently the good folks at Hornady did test the differences and here is what they found:

Several manufacturers offer match grade primers. ...(they) supposedly offer high consistency in ignition, theoretically improving accuracy. In this comparison, all components are the same: same case, same powder lot and charge, same bullet and seating depth, except one group is loaded with a standard primer while the other is loaded with a match grade primer.

Results looked like this:
five loads with standard primers yielded avg velocity of 3,338 fps and an SD of 38 with avg pressure of 48,320 C.U.P. and an SD of 1,775

five loads with match primers yielded avg velocity of 3,316 fps and an SD of 16 with avg pressure of 46,960 C.U.P. and an SD of 600.

However they also noted that

standard primers are also quite consistent. ...It probably requires a match grade firearm to reveal any significant difference.

From Hornady Handbook of Cartridge Reloading Rifle-Pistol Fourth Edition Vol 1 Seventh Printing 1999 Copyright 1991

So in that sense at least they do agree with you Versifier.

[versifier]

Along with a match grade rifle it likely also requires match grade bullets.

The last couple of red boxes I measured bullets from had .003 diameter variation and around 5gr weight variation. That alone could account for the minor differences they measured, and I'll bet dollars to donuts they would see the same group-to-group differences with standard primers alone as well as with match primers alone. To be fair, Speer, Rems, and Win bullets are similarly inconsistent too. I would have hoped that a published "test" would have used more than just five rounds of each, but if it had I think they'd have said so. And they didn't. Ten rounds fired just isn't enough data to base anything on, even an opinion. That isn't even funny, just sad.

I did not own a chrono when I did my testing. I used Sierra GK bullets (.30cal 150gr SBT and .22cal 55gr SBT), measuring group sizes alone. I used GK not MK bullets as previous testing in both rifles, the .308 @100yds and the .22-250 @1-400yds, yielded the same average group sizes with both hunting and match bullets. Interestingly, according to my notes with the .22-250 the 400yd POI didn't even shift more than an inch between GK and MK. No egg was safe. So I just used the regular GK's that I hunted with. There was a LOT of walking back and forth involved that summer, but I sure got to know the triggers of those rifles very well. As I recall, the 2000 bullets altogether cost under $100 and back then in the early 80's shipping from Midway was free. Primers cost less than $5/1000 and powder was somewhere around $7/lb., those I got wholesale at my friend's gun shop. Today those .30cal bullets are almost $30/100. I could not afford to do the same test today, even with my chrono, and I would likely want to try at least two more brands of regular and match primers to get what I would consider definitive results. And it would take me years to do the testing.

As it is I doubt I will live long enough to test cast bullets from all the different moulds I have now in all my different rifles. That's enough for me.

[Kirbydoc]

I was surprised that Hornady published that with only five of each and the rest of the data shows they did not use any more (unless they used 500 of each and these were aggregate totals). Perhaps the folks at Hornady would disavow that test today it was published some 23 years ago. I sent Hornady a request for clarification of test procedures and where they stand on that test today. I will keep you posted.

Reload & Shoot Safely and Wisely.

[versifier]

I would be very interested to hear what they had to say.

[Kirbydoc]

I will not comment on this but here is Hornady's response:

Mr. "Kirbydoc" this test was done with 10 new cases 5 loaded with the Standard LR primer and 5 loaded with the Match grade LR primers to show how much more consistent the Match primers would keep the Standard Deviation. They were all loaded with the same powder and bullet just as a simple test to show why you may want to use Match primers to load extremely accurate rounds. And that you are also reducing some of the loads pressure while maintaining the velocity. Thanks

Bold face and underlines are mine.

[Hellrazor]

And people used to grumble when I shot 3 shot test loads instead of 5...... I guess I can use 1 now

[versifier]

Thanks for posting that. I now have to wonder how much more of the info they've been putting out results from equally "simple tests". I may want to take everything they publish with a few grains of salt in the future. At least they answered you.

[Kirbydoc]

Versifier,
I almost didn't post it. It seems like a quick test just to see if somebody's idea might have some merit.
You have to wonder with their facilities and all the bullets and brass they have, why?? Making up even 20 rounds of each would have shown me that there was merit to the argument (not proof but merit). This way I think maybe...but hey how do I know? I may do the test myself once I get a chrono just to see what happens. Don't have one yet. Just one more thing to add to my list.

[versifier]

I am glad you did post it. As my Irish grandmother used to say: "Better to face an ugly truth than to live a pretty lie." Presenting it the way they did was in my opinion irresponsible at best. All their other data is now suspect for me.

[Kirbydoc]

Versifier, my tendency is to defend people's attempts and when I realized they hadn't changed their stance I was very sad. It was hard to post that. Even harder without comment of some kind.
Do you think 25 of each with carefully selected, weight-sorted cases and bullets would give us a hint as to potential differences? (That's 5X what they did). This isn't something I can do right now but in the future when I get my hands on a chrono. Also do you think I would need a pressure-trace or would velocity give us enough information to say the argument has merit and how many would we really need to consider it proof? A hundred of each? I sure can't afford a thousand.

Definition of Buff: Big Ugly Fat Fella! Not what the kids think AT ALL!