Quick load velocity way off

[elkhunter11]

Originally Posted by Salavee

Of course I read it. What he meant by that is that if you arrived at a certain burn rate number with a clean barrel, then tried to duplicate it with a badly fouled barrel or some other difference the results could vary a bit. Maybe even a different barrel altogether for that matter.. That situation can be tweaked , or fudged if you will, by adding or subtracting a grain or three to the bullets weight to compensatefor the variance in MV and/or pressure. You can't do that with extremely large differences.For those of us who keep our rifles fairly clean it really doesn't present a problem. It works best when you want to get the QL predictions down to a foot or so of the original Chronograph average.

He also specifically mentioned a tight or loose barrel, and different land configurations, so it's not just a matter of fouled or clean barrels. And of course chamber dimensions do vary as do throat lengths, so powder burn rate is not the only variable, so varying the powder burn rate, is a work around, rather than dealing with all of the actual factors that cause the velocity variances.

[huntingfamily]

QL is a powerful ballistic modelling program. I haven't looked at a manual or online load data for a long time.

I find it particularly rewarding with cartridges that are 'loaded down' due to action, early military use or just not a lot of data for.
I load for 6.5x55, 7x57, 280 Rem and many others but for these cartridges it has been fantastic.

For load selection the comparisons of all powders and projectiles can't be beat.
I find the technical articles on OCW and OBT sites on tuning Quickload are super interesting. Sure it has the default settings, but it gets really fun once you really start exploring within it.

Anyways, that's my .02...

[Salavee]

Originally Posted by elkhunter11

He also specifically mentioned a tight or loose barrel, and different land configurations, so it's not just a matter of fouled or clean barrels. And of course chamber dimensions do vary as do throat lengths, so powder burn rate is not the only variable, so varying the powder burn rate, is a work around, rather than dealing with all of the actual factors that cause the velocity variances.

If one used a different barrel or a totally different rifle, which are sure to cause variences, dont you think it would be best to start over from scratch with a chrono ?
I think I would. It would be a much better approach than attempting to fault some great software .. that you have never used and have absolutely no clue about. Don't knock it 'til you've tried it. You may even get an education to boot.

[elkhunter11]

Originally Posted by Salavee

If one used a different barrel or a totally different rifle, which are sure to cause variences, dont you think it would be best to start over from scratch with a chrono ?
I think I would. It would be a much better approach than attempting to fault some great software .. that you have never used and have absolutely no clue about. Don't knock it 'til you've tried it. You may even get an education to boot.

What I am saying, is that I wouldn't blame a difference of over 250fps between the measured and calculated velocities on the powder burn rate alone. A difference in chamber and barrel dimensions, or in case capacity, could be as large of a factor as the burn rate of the particular lot of powder . The article from your link even states that powder rate isn't the only issue. I have run the same handloads through two different rifles with the same length barrel, and have seen differences of over 150fps, and the ammunition was loaded with powder and components from the same lots, so obviously the powder burn rate was not a factor. Obviously the difference was due to the chamber/ throat/ barrel dimension variances. Yet if you did a calculation for that load in both rifles, the calculated velocity would be the same.

[Salavee]

Originally Posted by elkhunter11

What I am saying, is that I wouldn't blame a difference of over 250fps between the measured and calculated velocities on the powder burn rate alone. A difference in chamber and barrel dimensions, or in case capacity, could be as large of a factor as the burn rate of the particular lot of powder . The article from your link even states that powder rate isn't the only issue. I have run the same handloads through two different rifles with the same length barrel, and have seen differences of over 150fps, and the ammunition was loaded with powder and components from the same lots, so obviously the powder burn rate was not a factor. Obviously the difference was due to the chamber/ throat/ barrel dimension variances. Yet if you did a calculation for that load in both rifles, the calculated velocity would be the same.

.. which is exactly why i suggested starting from scatch. Is this somethimg you dicovered.. two different rifles can produce to different velocities with
the exact same load? Brilliant !!

[elkhunter11]

Originally Posted by Salavee

.. which is exactly why i suggested starting from scatch. Is this somethimg you dicovered.. two different rifles can produce to different velocities with
the exact same load? Brilliant !!

The fact that two different rifles can produce a difference of 150fps using the exact same components from the exact same containers, does prove that the powder burning rate isn't causing the difference. So adjusting the powder burn rate to make the calculated velocities match the measured velocity for both rifles, is simply "fudging" the numbers, while ignoring the real factors that are causing the difference in velocity.

[Salavee]

Originally Posted by elkhunter11

The fact that two different rifles can produce a difference of 150fps using the exact same components from the exact same containers, does prove that the powder burning rate isn't causing the difference. So adjusting the powder burn rate to make the calculated velocities match the measured velocity for both rifles, is simply "fudging" the numbers, while ignoring the real factors that are causing the difference in velocity.

I think you might find that what is causing the velocity difference is different pressures, which will alter burn rates. Back to Square One. You had best explain your objections to all the multi thousands who use QL and would disagree with you. I'm out. Write a White Paper.

[elkhunter11]

Originally Posted by Salavee

I think you might find that what is causing the velocity difference is different pressures, which will alter burn rates. Back to Square One. You had best explain your objections to all the multi thousands who use QL and would disagree with you. I'm out. Write a White Paper.

So do you change the burn rate for every different powder charge you use, to compensate for the change in pressure?

[Salavee]

Originally Posted by elkhunter11

So do you change the burn rate for every different powder charge you use, to compensate for the change in pressure?

Are you playing stupid , or is that really you?

[gunluvr]

Originally Posted by Dubious

can any of the guys that have quick load have a look at a load for me I have entered all my data and its saying my velocity should be 3133fps I fired the test load at the range and it cam out at 3422 measured by Labradar. my load details are

bullet 100 gr Speer BTSP #1408
cartridge .25-06 ack imp
cartridge length is 3.180
barrel length 26"
case capacity in h20 72.4
powder h4831sc
charge weight is 58.0 gr

I hear the program is pretty accurate but 269fps seems a bit extreme what data am I putting in wrong?

Changing from one brass manufacturer to another can lead to a large discrepancy in velocity. With one of my 308 rifles I see a difference of well over 100 fps between Win brass and RP brass. So your results may be due to choice of brass (or size of your chamber if you're fireforming your AI from regular 25-06 brass).

[elkhunter11]

Originally Posted by Salavee

Are you playing stupid , or is that really you?

Just using your own explanation, to show the fault in that explanation. Yes Quickload is a useful tool, but it does have flaws, and if you choose to place absolute trust in Quickload, and ignore the other tools and pressure signs, you can quickly get into trouble, just as you can if you blindly accept the loads in the loading manuals.In all cases, trust your chronograph, if there is a discrepancy, because actual measurements always trump calculations.

[Salavee]

Originally Posted by elkhunter11

Just using your own explanation, to show the fault in that explanation. Yes Quickload is a useful tool, but it does have flaws, and if you choose to place absolute trust in Quickload, and ignore the other tools and pressure signs, you can quickly get into trouble, just as you can if you blindly accept the loads in the loading manuals.In all cases, trust your chronograph, if there is a discrepancy, because actual measurements always trump calculations.

Give it a break Elk. .I've been handloading since I was 20 yrs old. I've been at it for 60 years now, without an incident. One thing for sure, my absolute trust
would not be vested in guys like you - or any other single source.

[elkhunter11]

Originally Posted by Salavee

Give it a break Elk. .I've been handloading since I was 20 yrs old. I've been at it for 60 years now, without an incident. One thing for sure, my absolute trust
would not be vested in guys like you - or any other single source.

I have been loading for over 45 years myself, without so much as a blown primer, and I have done so, without QL. I have never blindly trusted any manual or calculation, and I never will. The sad fact is that I have seen many blown primers and stuck bolts, as well as a few more serious incidents, because people did blindly trust data or calculations, with no load work up.

[Dubious]

the Speer data for the standard 25-06 shows a starting load of 51GR with an estimated speed of 2999fps I had started at 52 gr as I need a little more brass and was using it as a fire forming load my recorded velocity there was an average of 3195fps. the Speer data is using a 24" barrel and as you guys have pointed out I was not using the same components. Being an Ackley with no book data and generally nothing to go off other than max loads of parent cases I loaded up some rounds to get these results. This rifle has always shot fast and it doesn't like to show any signs of pressure this is why I picked up quick load as a reference none of the manufactures when emailed will give data for the Ackley usually they say something along the lines of we don't have data for wildcats.

So typically I follow the common practice of starting at the parent case max load for the starting load in this case with the Speer data 55GR @ 3215FPS. After working up .5 gr at a time I came to 59Gr and decided to stop cause my printed quick load data and my researched data were so wrong from my crono data. I know a lot of guys want to blame the crono data and say its incorrect but I have tested it against optical and magneto speed with similar results.

Ive fine tuned a bunch of variables from my first load and I'm going to back to the range today with a few more loads to see if I can get the adjusted quick load results. Hopefully this will spit out matching data so I can know where i'm sitting when i'm dreaming up the next new load at the computer.

[Don_Parsons]

PM Dr Mike in BC if you need more information.

https://forum.nosler.com/viewtopic.php?f=4&t=16470

Cheers from Don

👍