I just got QuickLoad and loaded it and am playing around with my new toy but have a question.

I can't figure out how to change (or find out) the default primer type. It doesn't even appear to tell you how to do it in the documention.

Anybody able to help me out???

TIA
Roi

510wells,
Quickload isn't smart enough to figure out the effect of different primers.

QL has many gross simplifications in the calculations. As you read through the manual, you'll be amazed the thing can work as well as it does. The bullet engraving force is represented by a pressure. Heat loss appears to not consider bore diameter (surface to volume ratio changes with diameter). Primers are not considered. The representation of burning rate is known to be off at medium and lower pressures.

That said, it does give useful information, and I feel I've learned a lot in studying its outputs. It is not a substitute for pressure tested, load book data. I have seen more than one report that its predictions of peak pressure can be off 10,000 psi. It is, of course, generally much better than that, but be careful.

In comparing it's outputs to load book data, I find it nearly always gives a good estimate of the what performance you can expect from a cartride, but it does not reliably tell you which powder to use nor how much powder to use. It will indicate what class (ie. "speed") of powder is best and about how much to use. It will not be able to tell you if 4895 is a better choice than 4064 or Reloder 15 -- it's not that accurate.

I've never noted much difference in primers - even magnum vs. standard primers. Why should QL users waste time worrying about primers?

You might seek out the June, 2004 issue of Handloader magazine. Barsness tried the same bullet, case, and charge over 3 different primers, and he ran the loads through a piezo pressure tester. Changing the primer raised pressures 25%. (Please keep in mind that proof loads begin at 30% over nominal max.)

The really interesting part is that fps went up only 2.5%, making it difficult to detect with only a chronograph. I've tried to get QL to simulate this behaviour by monkeying with start pressures, etc., but this real-world effect is beyond its simulation.

The December, 1997 issue of Handloader had an article by Petty on his investigations into primer effects. He used an Oehler strain gauge rig in his tests. Like Barsness, he found that fps swings were about 1/9 the pressure swings, and pressure swings of over 50% were observed.

So why doesn't QL have a primer variable? Because primers are not easy (impossible?) to predict reliably. The March, 1979 issue of the American Rifleman had an article by W.C. Davis on primer effects. He noted the Frankford Arsenal tried to characterize primers to predict the effect on ballistics. Tests such as duration of flash, pressure rise in a closed chamber, etc. were tried. No prediction could be made based on these tests.

Then there is the issue of firing pin shape, mass, and velocity...

Sorry, QL will never substitute for pressure tested load book data.

I've tested "magnum" primers vs. "standard primers" many times with everything else being equal. I've noticed NO differences in velocity, sometimes even less with the "magnum" primers. The only time there appeared to be a difference was with large charges or H870. This topic has been discussed before on this forum and the conclusion was the same as mine. Regards, AIU.

Guys,

Thanks for the answers, not what I expected or hoped for though. I've had different primers make as much as (roughly) 40 FPS difference and some real changes in group size. Like just under 1 MOA to about 2.5 MOA.

But I generally stick with one brand (Federal) as I mostly shoot big bore stuff. So if I'm consistant I guess it doesn't matter all that much and I'm in no way anything like a bench rest guy.

Again thanks for the replies

I realize that there are some strange burning powders that can get testing in big magnum cases (and H870 is one). But, I can't imagine primers making more than a 3-5% difference with safe handloads. (And the printed tests I've seen seem to indicate it is likely to be much less than that). I've had quickload for a couple years and enjoy it. It's been pretty accurate for the most part but I think of it more like an "interactive" reloading manual and it does need to be compared to other manuals.
I also like the ballistic program that comes with it because it charts out minute of angle corrections and that helps me recalibrate my Burris Ballistic plex scopes and my Premier reticle scopes for different guns and loads.
All in all very worthwhile and good enjoyment for the $$$$. Don't worry about the primer situation--differnces in powder lots seem to have more effect on the quickload outcomes. (Not to mention a "gazzillion" other inputs that affect velocity.)

In my oppinion the powder is the biggest source of failure!

On the other hand there seems to be no possibility to produce primers so accuratly that they always fire like the last...

Just weigh your primers...

Another observation on the effects of primer substitutions, this time from Mic McPherson in an older article of his, a copy of which can be found at leverguns.com:

quote:

Equally, note that primer substitutions have been proven to sometimes radically alter pressure – this is not unique, ballisticians tell horror stories of customers who haphazardly substituted primers and ran into king-sized problems – for example, combining a milder than suggested primer with Accurate #2 in a 9mm load and doubling pressure. Moreover, neither you nor anyone else can reliably predict results of any primer substitution. Use of a "hotter" primer can result in lower pressure and use of a "milder" primer can result in higher pressure – any result is possible and all have been observed. It is a unadulterated and unequivocal fact that anyone who professes to believe they can predict even the general trend resulting from such a substitution will have already demonstrated sufficient ignorance of reality as to make the results of any handloading decision based upon their further proclamations fraught with peril. Often such predictions hold, just as often those do not.

Lyman 48 has data on primer substitutions as well, but not nearly so dramatic as some of the other figures I've quoted, with pressures rising about 3.5 times as fast as fps. (This ratio of 3.5 to 1 seems to be common for component substitutions.)

Anyway, if you fellows have some pressure tested data regarding primer substitutions, I'd gladly add it to my notebook. With enough data, maybe I wouldn't be so chicken when it comes to reloading, and could load closer to book fps.