Quickload vs reality.....whats real???

[biffj]

I've been playing with a friends quickload program and finding a lot of odd info. For my .338 BR, .510 Whisper and the 6.5 X 47 it seems to be pretty close to real numbers. It is very interesting to try different powders and see how the pressure curves change and also to see that muzzle pressures are....for suppressors, subsonic gas guns and other such stuff it can be very informative. On the other hand the data on the .338 Lapua Mag seems way off from the results I have been getting. Using Lapua brass, Sierra 250 Matchkings and 93gr of retumbo in my Desert Tactical SRS I've been seeing chronographed speeds in the 2800-2850fps range. According to quickload I'm using a compressed load and should be seeing more like 2650 fps. I've set my barrel length and seating depth to what I really use yet it keeps telling me that most of the loads I'm using are over 100% of the capacity. I'm finding that I can shake the case and hear the powder moving....its not compressed. It seems like it could be a handy tool for working out which powders and what loads to start with but if it won't duplicate what I already know how good is it? What am I doing wrong that would keep it from working?? I'd buy the program myself if I knew it would work....

Thanks for any help

Frank

 

[fish30114]

Re: Quickload vs reality.....whats real???

I had a friend that was a co-owner of a rifle company-a mfg. He told me once that quickload was a great tool but in his opinion and experience it was as much of an art as a science. He often said that you had to 'kind of know what you were looking for' in order to benefit from it.

That kind of matches my experience, such as yours...

 

[Temp9]

Re: Quickload vs reality.....whats real???

Did you set your case capacity?

 

[biffj]

Re: Quickload vs reality.....whats real???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Temp9</div><div class="ubbcode-body">Did you set your case capacity? </div></div>

I used the capacity that we measured using water when we first bought the cases. The bullets are standard and listed in their database. I set the seating depth that we use as well because the mag allows the bullets to be seated way out. Overall length is about 3.750" and is longer than the standard 3.687" they have in their database. It should increase the capacity and it does but still not enough for what we really find. Seating the bullet further out drops the pressure and velocity as well.

Frank

 

[Temp9]

Re: Quickload vs reality.....whats real???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: biffj</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Temp9</div><div class="ubbcode-body">Did you set your case capacity? </div></div>

I used the capacity that we measured using water when we first bought the cases. The bullets are standard and listed in their database. I set the seating depth that we use as well because the mag allows the bullets to be seated way out. Overall length is about 3.750" and is longer than the standard 3.687" they have in their database. It should increase the capacity and it does but still not enough for what we really find. Seating the bullet further out drops the pressure and velocity as well.

Frank</div></div>

Case capacity should be measured with fired, non-sized cases. This will give you a more accurate representation of how the case acts during the firing process with that particular chamber. Take an average of at least 5 cases.

 

[Boogaloo]

Re: Quickload vs reality.....whats real???

Also, you need to keep in mind that powder manufacturers have a 10% variance lot to lot they are allowed to play within before they have to re-classify the powder. If you are seeing more than 10% variance between predicted (quickload) and observed (chrono) velocities, then one of the first places to look is in the Ba value for the powder you are loading at the time. You can change the Ba value that is set in Quickload a little at a time until the predicted velocity matches the observed velocity. This is of course assuming that EVERYTHING else is a known constant like actual measured case capacity (as the other poster eluded to), but seating depth, OAL etc. are all important inputs to Quickload.

If you do change the Ba value in Quickload and it aligns with your observed velocity, then you should save that powder in the program with a new name. I give it a lot # or date of purchase tag so that I know that it is NOT the powder Hartmut tested when the revision I have was released.

Just so you know, the actual difference between 2650 fps and 2850 fps is only 7.27% so it is well within the accuracy you can generally expect with Quickload.

On a final note, temperature may be making up the difference you are observing. Quickload defaults to 70f so make sure you change that input when working up your loads in Quickload.

 

[shootist2004]

Re: Quickload vs reality.....whats real???

do they actually have inputs for suppressors?

 

[jfseaman]

Now reliable is QuickLOAD for developing loads for a caliber+powder combination not listed in any manuals?

 

[Heman]

When I was getting my .280 Rem up and running I didn't have any manuals to use as I was using the Sierra 175gr smk and H1000 powder. Quickload proved very usefull and the velocity numbers it calculates seem to be very close to real world. Close enough I can use the Quickload velocity numbers plug them into JBM and I'm easily on paper usually 9 or 10 ring on the 1k target. Couple of things that do help.
1. Enter your water capacity of fired cases.
2. Go in an re-enter the case dimensions. Some of the mysterious "weighting factors" are way off, .223 Rem comes to mind.
3. Of all the powders I shoot the VV powders seem to be aprox 150fps slow in QL. My .243/105 N160 load is close to 3300fps but QL will say 3,150ish, same with my .260/123gr load with N150 it's off by about 150fps. Not sure why but just seems to be a ballpark number I've noticed with the VV powder. The preasure calculations are correct as when QL says it gets hot that is where it gets hot, just the bullet is going about 150fps faster, so its a good thing.

 

[Lt. Arclight]

I've had Quick Load since it was initially introduced. Provided you fill in the appropriate data,the program does a great job to get you in the ballpark. I've used it mostly for 338LM and 50BMG. The program was VERY accurate when I tried 338LM using very slow powders ie,H50BMG,VV24N41 and surplus canister powders.

Even though you can use a chronograph-nothing beats real world ballistics. The Quick Target portion of the program also works well. I will say that the variation in powder lots can really skew your dope when you change Lots. Quick load seems to lean toward the conservative side. Is it worth it? I think so.

 

[jfseaman]

Thanks guys. That's what I needed. Just finished water weighing my brass. QL was quite low on that scale.

Also gave me the real brass weight vs water capacity that I've talked about.

BTW: So far, in my limited experience, ~10grs of brass = ~1grs less of H2O. Which is with in a reasonable error of what I had been using anyway.

 

[Jedi]

Like any computer based model
output is determined by input
Shit in shit out

QL has several fields which need "No shit" data vs default to ensure optimal result
if your using default input values then your not really using tool to its fullest capability

Correctly optimized QL can yield very accurate results
It is a very powerful tool most fail to utilize its full potential has they really have not taken time to learn how to correctly use it

 

[thefitter]

I scoffed at QL for years. Then in a moment of boredom I bought it. I ran all the pet loads that I developed by the seat of my pants trough it and it was within 10fps of my crono data. I will never buy another loading manual. It is especially good for designing new rifle builds.

But as Jedi said - "Shit in shit out"...

I'm still learning it's nuances. Call the guy who sells it, he's very easy to talk to and is a wealth of knowledge.

 

[Jaxdialation]

I haven't gained any insight from using ql that a mandatory (for me) pressure testing process didn't give me.

I scoffed at QL for years. Then in a moment of boredom I bought it. I ran all the pet loads that I developed by the seat of my pants trough it and it was within 10fps of my crono data. I will never buy another loading manual. It is especially good for designing new rifle builds.

But as Jedi said - "Shit in shit out"...

I'm still learning it's nuances. Call the guy who sells it, he's very easy to talk to and is a wealth of knowledge.

 

[jfseaman]

Hi John,

Please, what is your "mandatory" pressure testing process?

 

[Lt. Arclight]

QuickLoad always errs on the side of caution. But if you provide the appropriate case capacity-it will get you real close. Today,everybody has a PC or laptop andthe program is reasonably priced and a good tool to have.