Just picked up a copy of quickload to toy with.  I initially plugged in the AR round I worked up this weekend.  Pretty dang neat stuff.  

I have two sources of confusion, one minor, one major.

The major:  I entered the data on a .308 load I'm looking to work up.  In quickload I entered .308win, sierra 175bthp, 45.5gr of imr 4064 (45.6 is listed max on Hodgdon's site), ran the numbers and it comes up as over pressure.  It shows it at 68050psi.  In quickload you aren't under max until you dial it back to 44gr.  This is a wee confusing to me.  YES, I know you work loads up, and I'd do this regardless but is it typical for one source to be so far from another??  If YOU were going to draw a line in the sand for a max load, which source would you go with and why??  

The minor confusion:  After working up a load this weekend I plugged all the data into quickload.  .224 harnady 60gr v-max, 2.250 OAL, 24.7gr of TAC input as .223 win SAAMI.  Quicload tells me my round is only burning 85% of the powder.  I see how to go in and find a powder combo that is more efficient but is this even an issue?  Should I find a new powder bullet combo, or new powder?

Thanks for any input.  This quicload is nifty stuff!!!

Lyman manual shows max at 44 gr also for the 308..

Always use multiple references.

Are you measuring your fired brass for h2o capacity? Should help make QL more accurate.

I don't, but I should.  Just seems such a PITA, lol.

I also have the lyman, sierra, hornady manuals at home.  I'm at work so I just took a peek at Hodgdon and quickload.  

What the general idea, look at all the max loads listed and average them out for a general idea before working up a load??

Case capacity has a major impact on pressure as you should know already if you are loading 308 for example if you are comparing LC vs Win brass.  If you are bothering to use QL, you cannot skip case capacity....


 

does QL handle (model) compressed loads well? I haven't messed with it to know.

Copy that.  I'm aware case capacity makes a difference.  The load I worked up over the weekend for .223 will only be loaded into the brass I ran the OCW test in.  All other headstamps are set aside for another load someday.  

Two questions on case capacity.  I read that it is to be measured after being fired, while still primed.....    Will the capacity not change once I've resized and trimmed the case??

Also, for each headstamp, I can just measure one or two casings and assume the rest of that lot are the same??

Thanks!!!

Yes.    See post #2  http://www.thehighroad.org/showthread.php?t=756633

Copy that.  So how does one get a good case volume to enter into quickload??  I'm going to take a stab at it.  Resize a half dozen without resizing, measure volume and take the average??

Quickload suggests using fired case capacity for loads generating more than 30k, resized capacity if less. I presume that over 30k what the chamber allows capacity to become is more important/representative than the re-sized capacity.

i think the second question has been answered.

water has a density of 1.0000 grams/cubic centimeter
If you want even more accuracy you can measure its temperature and look up the density.
Weight the case, fill with water, weigh again.

No, you don't use those values off the top. You back off those values and work up the load to see if your situation shows signs of pressure before or at those levels. If you see signs of high pressure, it doesn't pay to keep going higher just because some recipe quoted a higher charge.

If you want to play with higher pressures, get instrumented with strain gages and play it safe.

This is what I was referring to.  Average the published max charges, then back off from that.

That is correct. There could be lots of reasons why your particular situation can give different results compared to the published values, even if you follow the load recipe exactly.

For example, is your rig identical to the one they tested with? Even if your bbl length and model are the same, sometimes they way they chamber rigs will change over the years and you can see differences. Try to see what type of rig your particular data applies too. Some manuals use test bbls and others use typical guns. In any case, especially when you see discrepancies between books, that is a warning sign to slow down, not to speed up. You should be asking yourself if they are just being lawyered down or if those pressures are real.

You use a trial process to incrementally increase the load to approach the maximums in the manuals, you don't just jump straight to them.

You must learn to watch for pressure signs if you are not instrumented with transducers like strain gages. In general, the manuals don't want to have you blow up your gun, but every one of them that I can find will tell you to back of by some percentage when you try to approach the max. If you use a chronograph and watch your brass closely you can make good loads without the strain gages. Using a chronograph is also not a license to try and add charge till you match someone else's speed. You use it as a guide to look for signs of trouble and process control, not as a substitute for common sense.

I use Quickload.

Its just a guideline, never gospel.

My Beta Master (who makes up these names?) chronograph routinely reports velocity for 5.56-class rounds to be 90 fps SLOWER than what Quickload predicts.

Quickload has given me numbers for light-bullet .308 loads that look "very safe," yet the primers are flat as a pancake.

You probably won't blow up any guns if you obey Quickload.
That doesn't mean the loads are well-suited for your gun.

Not sure what you plugged into QL, but here is what I got.

Cartridge          : .223 Rem. (SAAMI)

Bullet             : .224, 60, Hornady V-MAX FB 22281

Cartridge O.A.L. L6: 2.250 inch or 57.15 mm

Barrel Length      : 24.0 inch or 609.6 mm

Powder             : Ramshot TAC



Predicted data by increasing and decreasing the given charge,

incremented in steps of 2.0% of nominal charge.

CAUTION: Figures exceed maximum and minimum recommended loads !



Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time

 %       %    Grains   fps   ft.lbs    psi    psi      %        ms



-20.0   79    19.76   2447     797   26477   5199     81.8    1.385

-18.0   81    20.25   2507     838   28254   5380     83.2    1.350

-16.0   83    20.75   2569     879   30157   5558     84.6    1.316

-14.0   85    21.24   2630     922   32195   5733     86.0    1.282

-12.0   87    21.74   2692     965   34379   5904     87.3    1.250

-10.0   89    22.23   2754    1010   36719   6070     88.5    1.219

-08.0   91    22.72   2816    1056   39236   6231     89.7    1.183

-06.0   93    23.22   2878    1103   41938   6386     90.9    1.148

-04.0   95    23.71   2940    1152   44839   6535     92.0    1.115

-02.0   97    24.21   3002    1201   47971   6676     93.0    1.083  ! Near Maximum !

+00.0   99    24.70   3065    1252   51341   6810     94.0    1.052  ! Near Maximum !

+02.0  101    25.19   3127    1303   54975   6936     94.9    1.023  !DANGEROUS LOAD-DO NOT USE!

+04.0  103    25.69   3190    1356   58871   7053     95.7    0.994  !DANGEROUS LOAD-DO NOT USE!

+06.0  105    26.18   3253    1409   63068   7161     96.5    0.966  !DANGEROUS LOAD-DO NOT USE!

+08.0  107    26.68   3315    1464   67605   7259     97.2    0.939  !DANGEROUS LOAD-DO NOT USE!

+10.0  109    27.17   3378    1520   72520   7346     97.8    0.913  !DANGEROUS LOAD-DO NOT USE!



Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge

Data for burning rate increased by 10% relative to nominal value:

+Ba     99    24.70   3229    1389   61581   6916     98.6    0.976  !DANGEROUS LOAD-DO NOT USE!

Data for burning rate decreased by 10% relative to nominal value:

-Ba     99    24.70   2859    1089   41820   6405     86.0    1.150   

Quick load is interesting but sometimes I just want to forget it. I'll work up a load over the chronograph and some combos QL is right on, others are way off. I'll tweak the burn rate for a powder to match readings, but use that same powder with a different bullet and the QL prediction will often be way off. It is useful for getting you into the ballpark, especially when there isn't much published data, but you still need to do a standard load workup for accuracy and safety.

Forgive me, I forgot to add I've got a 16" barrel.  

Still comes out to 90% burn.

Different bullets will have different bearing lengths and profiles, which will change your work ups.

Which QL is supposed to take into account but it doesn't always match real world which is my point. In the end you will have to do a load workup anyway so QL is really only good for real rough numbers.

This may have been covered, but just like a reloading manual, Quickload can be no more than a guideline.

Powder burn rates are not static, QL powder burn rates are. Even if you have all the inputs perfect, the outputs will not always match because of burn rates alone. Different specifics will change the burn rate for a given powder.