PDA

View Full Version : Standard vs Match primers testing



Kirbydoc
09-24-2014, 04:47 AM
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
09-24-2014, 03:02 PM
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. [smilie=1: 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
09-24-2014, 11:08 PM
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. :neutral:

Reload & Shoot Safely and Wisely.

versifier
09-24-2014, 11:49 PM
I would be very interested to hear what they had to say.

Kirbydoc
09-27-2014, 07:22 PM
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
09-27-2014, 08:14 PM
And people used to grumble when I shot 3 shot test loads instead of 5...... I guess I can use 1 now

versifier
09-27-2014, 08:20 PM
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
09-27-2014, 11:52 PM
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
09-28-2014, 02:36 AM
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
09-28-2014, 09:01 PM
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!

danptobin
09-28-2014, 09:21 PM
you would need some way of measuring pressure. a pressure trace will let you compare pressure readings from shot to shot i used a pressure trace like greg had on my 25 wssm and was able to compare the pressure readings from shot to shot. you would also need to make sure the powder all came from the same container as different lots of powder can vary slightly. you must also maintain a consistant barrel and air temperature. exact neck tension on the bullets would also be a factor. once the difference or lack of is proven on one powder and charge weight you would need to change the charge weight by a small amount and see if the results stay the same. then reapeat the same increment and direction of charge weight change and do so multiple times. then do the same with multiple powders just to be sure that the results are true in general or just in certain situations. all in all cci200s are hard to beat. not always the best with every load but so far always good with ever load

versifier
09-28-2014, 09:52 PM
I agree with Dan. I think first off if you were going to do it right one would need an extremely accurate .25MOA or better benchrest rifle, a chrono for velocity, a strain gage for pressure measurement and graphing pressure curves, one lot of power, very carefully weighed and sorted cases, weighed and sorted Berger or Sierra match bullets, a lot of patience to let the barrel cool after each shot, and a laser thermometer to double check it.

Then you might be able to see something meaningful with a hundred rounds of each.

And then like Dan says, you'd want to try another charge level and another powder. (Not sure what a pressure trace is, we may be talking about the same thing.)

Oh, and a woodstove would be handy too, so the Hornady manual would serve a useful purpose lighting it. I'm glad I never wasted my money buying one. I was merely non-plussed about the company before this and only truly negative about their die sets and One-Shot spray lube; now I no longer trust their loading data and I see no reason to consider buying or using any of their other products. Not that I have ever been into buying patent-expired copies like their presses and powder measures anyway. I am still looking for someone I dislike enough to sell my HDY 6.5TCU die set to, but no one I know who shoots is enough of an a$$hole that I would wish it on them. Oh well.

Guess I'll never be asked to review any of their stuff now, huh? [smilie=p:

danptobin
09-28-2014, 10:02 PM
now now vers their corlokt sorry interlock bullets are cheap decent and available in calibers and weights remmy doesnt offer.

Hellrazor
09-28-2014, 11:15 PM
Now now.. no reloading manual has been all that great since the great lawyerism regime came along. It is hilarious comparing books and min/max loads. I have some older books showing max loads way over todays for the same powder.

versifier
09-29-2014, 12:55 AM
I'm just being publicly disgusted, that's all.

I have been asking myself for years why I should buy the red box when it costs the same as the green box or the black box and the cup&core bullets in the green and black boxes are made to tighter tolerances and notably more accurate in most of my rifles? So I haven't been buying them. Maybe if I shot more jacketed bullets these days I'd be willing to cut them more slack, but I don't. Especially now since the prices have risen along with everyone else's to absolutely outrageous levels with no improvement in quality or accuracy.

Unless I want to load for the Carcano, you have me there. No one else makes the right diameter, but in my rifle even the correct diameter bullets don't shoot much better than standard .264's or my or cast .266 bullets, 8" vs 10" groups. It will live in the safe until I trade it off.

Me too HR, but at least in the other manuals I have (Lyman, Sierra, & Nosler - Lee uses others' data and always needs to be triple checked) the science mostly is, well... science. Not wishful thinking. The methodology and testing parameters are clear and explained.

As to those amazing variations in published data we all marvel at, I have always been one to look up a load for a new-to-me cartridge in as many sources as I can find and compare them all first before I come up with a test ladder. And then I set up the chrono to check what actually happens in my rifles at each charge increment, always a good bit different than any of the various test rifles used to work up the published data. Like you, I have also been loading long enough to remember when the data all got lawyerized back in the 80's. And sometimes there have been actual changes in the powders themselves, too, so it's not always just the lawyers. Multiple current sources are the best deal on life insurance there is, even if some of the data is watered down a bit. They do have to protect themselves from the natural tendencies of morons to blow themselves up unsupervised, and the possibility that Bubba-Sue might have been a bit hungover or otherwise distracted when she entered their test data into the charge table for publication. (Also the reason why I ask everyone to be very careful about they way we post actual charge weights here for jacketed loads.) If the rifle is at its most accurate with hotter loads I am mic'ing cases and working up loads in warmer weather anyway just to be safe. Some of my rifles seem to have read those older manuals, but I will generally try other powders before going with a near or over published red line load and am perfectly happy with a slower but still acceptably accurate load. No dead critter has ever remarked about a few hundred fps difference as long as the bullet was correctly placed. Targets don't complain no matter what, you just measure the groups, check POI vs. POA and adjust your sights accordingly.

But I think the real issue here for me is one of trust. I like to be confident that what is printed in my loading manuals (simple human data entry error notwithstanding) has been carefully thought out and thoroughly tested, with enough rounds fired so that the results generated are statistically meaningful. To find out they printed such fertilizer and continue to defend it as meaningful fact over twenty years later (as proven clearly by their reply to Kirbydoc) is a bit too much for me. It's like if I learn later that someone I thought I could trust lied to me in the past, then I have to reevaluate everything else they have told me in the light of that lie, and then everything else they tell me after I find out needs to be confirmed elsewhere before I accept it. "Bubba Science" instead of the real thing when they could so easily have done a meaningful test blows that trust.