QL v3.6 just arrived and its conflicting info

[Autorotate]

Fitch

Nobody is trying to convince anyone of anything but you Sir.

You make reference to articles you've read about guns blowing up with ammo that has deep seated bullets.

Phorwath details the results of a range day; I state my observations mimick his, and you state the data is meaningless.

Why would you challenge the observation of others, when you have yet to experience this yourself? Have you done any chrono testing at different seating depths? I'm assuming not, as you haven't stated such.

Might I suggest this topic is beyond you grasping it, until you load some yourself and see the results yourself. 30 rounds per seating depth and powder charge you say. Better order a barrel

Good luck!

 

[Pdvdh]

We can agree to disagree about this.

Fitch

I'd keep the mind open to the experiences to the contrary. Conduct some additional research and my guess is you may come around to the conclusion that the natural gas law relationships of pressure, temperature, and volume do not apply to the dynamic scenario of a rapidly increasing volume. The natural gas law only applies to static environments, which are maintained in a state of equilibrium.

I doubt that QL software, or most any other software, could account for some of the minutia (yet real factors) occuring when the trigger is pulled and the fury of hell is unleashed.

 

[datsjeep]

Phorwath is right.
The reason field velocities/pressures go down with deeper seating, is that EARLY pressure(peak) is reduced as you move from the lands. The latter having a greater affect(to a point), than the very tiny bullet displacement changes in seating.
QL does not automatically compensate, but allows you to manually adjust for it, with 'starting pressure'. You should account for it with trial & error to match chrono velocities.
If it seems to suck that you would have to do this, try it with ANY other reloading system...

Thread starter, I'm curious, why did you change 'case length'?
This is not usual, and in doing so you must also adjust 'case capacity' as appropriate.
Again, this is a manual calibration.

As painful as it may seem at times, the true value in QL is in it's CALIBRATED results. Nothing else provides this for reloaders.

Other factors, some mentioned, are weighting factor, cross-sectional bore area, shank seating depth, starting pressure, powder temp, powder factors(per lot).
There are a lot of little details to watch, the writer of this program has himself missed, and you have to catch them & correct them.
Wrong bullet dimensions
Inconsistent cross-sectional bore area
Incorrect weighting factor(for cartridge)
And factors not automatically updating with changes(like case length to capacity).

So don't assume anything is actually correct until you've measured so across a chrono.

Wow, interesting debate I started. Looking at this from a physics point of view. I assume when you seat a bullet closer to the lands you have two things happening. An increase of preasure caused from a shorter jump and a decrease in preasure caused from detination in a larger area of volume. Seating it deeper has the reverse effect but still one factor providing an increase and one a decrease in preasure. I think in both instances one will out weight the other which is why you will see either an increase or decrease of both velocity and preasure. All things are not equal.


I didnt changed the case length but I did change the cartridge length. I did however do a water test for maximum case capacity overflow which averaged out to the default in QL.

Since you brought it up this creates my 2nd question. According to QL with a cartridge length of 2.895 and Usable case capacity of 72.699 along with 72.5 grains of Retumbo how do I have a Filling/ L.R. of 107.6% shouldn't it be 99.73% or is this calculating something other than case capacity?

 

[Autorotate]

According to QL with a cartridge length of 2.895 and Usable case capacity of 72.699 along with 72.5 grains of Retumbo how do I have a Filling/ L.R. of 107.6% shouldn't it be 99.73% or is this calculating something other than case capacity?

That is a percentage of useable case capacity. The seated bullet occupies case volume.

 

[datsjeep]

That is a percentage of useable case capacity. The seated bullet occupies case volume.

I understand that however max case overflow is 79.5. Volume occupied by bullet is 6.801 leaving the useable capacity of 72.699. With 72 grains of powder am I not actually using 99.73% of the usable space?

 

[Autorotate]

I understand that however max case overflow is 79.5. Volume occupied by bullet is 6.801 leaving the useable capacity of 72.699. With 72 grains of powder am I not actually using 99.73% of the usable space?

I'm sorry, jumped at the common solution there.

Are you able to post a screen shot of what you're seeing?

 

[Mikecr]

QL case capacity is in inches of H20, which does not correlate directly with grains of Retumbo...

Also, notice how cartridge length affects seating depth. One is assumed, and so adjusts with the other.
If capacity is right(H20 capacity) then there is no reason to fiddle with cartridge length. Just enter the actual bullet shank seating and your good.

 

[datsjeep]

I'm sorry, jumped at the common solution there.

Are you able to post a screen shot of what you're seeing?

Screen shot is on my 1st post.

 

[Autorotate]

I'm puzzled here myself...

What does the loading/filling ratio say in the text file in the lower left of the screen for Retumbo....does it correlate with the ratio in the upper right?

 

[datsjeep]

Yes it sure does

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms
-20.0 86 58.00 2400 1918 28078 11233 91.9 1.671
-18.0 88 59.45 2467 2027 30058 11632 93.5 1.628
-16.0 90 60.90 2535 2141 32188 12007 95.0 1.585
-14.0 93 62.35 2604 2258 34480 12355 96.3 1.544
-12.0 95 63.80 2672 2378 36950 12672 97.4 1.503
-10.0 97 65.25 2741 2502 39614 12955 98.3 1.452
-08.0 99 66.70 2809 2629 42487 13201 99.1 1.404
-06.0 101 68.15 2878 2758 45593 13408 99.6 1.357
-04.0 103 69.60 2945 2890 48952 13573 99.9 1.312
-02.0 105 71.05 3013 3023 52588 13694 100.0 1.268
+00.0 108 72.50 3079 3158 56536 13790 100.0 1.226 ! Near Maximum !

 

[datsjeep]

Maybe the better question is what number is to much? If QL says 107% is that Ok (the load will not be to compressed) where 110% will always be to much. Is this just a trial and error thing or should I do my own math and stay below 100%

 

[Mikecr]

The filling ratio is another value(like cartridge length) that doesn't matter.

This is because of variance in powder bulk density.
Powder changes from lot to lot in this regard and others, and no two people drop powder the same.
For example, I use a 12" drop tube. If you don't, your results will be different. Doesn't matter.

If you enable tool tips, and hold the cursor over filling ratio there is a fair explanation.

 

[Pdvdh]

The QL software sounds very interesting. Data I've seen generated with QL has usually been a close match to my personal experiences.