More Quickload Data and observations


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Boogaloo
September 23, 2012, 05:45 PM
So, I went a couple of steps further in determining what the case volume is on my cases (All Lake City once fired) and popped out the spent primers on several fire formed (fired in my rifle) cases. I then plugged the flash hole with glycerin soap because it is slightly clear and allowed me to shine a light below the primer pocket and see into the case mouth so I could remove any extruded soap from inside the case. The idea was to completely plug the flash hole, but not take up any space in the case, so I could get a 100% accurate measurement of the case volume using distilled water.

The average case volume after measuring 10 cases this way was 30.6 grains of water.

I decided to test 3 different powders this weekend:

Ramshot TAC
Ramshot X-Terminator
Hodgdon BLC-2

The temperature out at my range was slated to be between 83-85f on Saturday, so I set QuickLoad up accordingly and loaded all 3 powders for 85f

I loaded up 20 cartridges (each) in a 5 rung ladder for the TAC and the BLC-2. Each rung was marked with a different color sharpie on the bottom of the case for easy identification as seen in the picture below:

http://www.boogalootactical.com/pics/QL-Issues/9-22-Data/ladder.jpg

Here is how the ladder looked as far a charge volume(s):

TAC: (1) 25.5 gr. (2) 25.9 gr. (3) 26.4 gr. (4) 26.9 gr. (5) 27.3 gr.

BLC-2: (1) 26.6 gr. (2) 27.0 gr. (3) 27.5 gr. (4) 28.0 gr. (5) 28.5 gr.

For the X-Terminator, I did NOT load up a ladder. I loaded up a box of cartridges using a safe medium load to test with some 69 gr. PRVI HPBT bullets and ran them across the chrono just to see where the stood, more on that load at the end of this post..

All of the loads in both the TAC and BLC-2 ladders were built using Montana Gold 55gr. FMJ-BT bullets. I call these bullets boat tails, even though Montan Gold does not list them as such, but they do in fact have a very slight boat tail design which I measured and entered into QL. Bullets were seated for a COAL of 2.255" No fewer than half of the finished cartridges were also checked with a comparator with results not exceeding .003". I use a competition seating die on one of my Dillon 1050's. ALL cases were once fired, LC-05 headstamp, completely prepped using an RCBS case prep station.

I had 2 test rifles with me (AR-15's) that I personally built.

(1) Satern 16" barrel, 1:8 Wylde chambered .

(2) FN 16" barrel, 1:7 NATO chambered .

The chrono was set up approximately 10 feet in front of the rifle(s) using the infra red sky screens. It was a crystal clear day, and the weather web was right on the money, as it was 85f with a slight breeze blowing when the testing commenced.

The idea going in to this test was to shoot 10 rounds from each rung through each of the (2) rifles across the chrono during the hottest part of the day to limit temperature change variations.

Here is a screen grab of the chrono download for the TAC ladder. The data in the far left column indicates the gun used: "B-16" = Billet rifle with Satern barrel and "M-S 16" = Mil-Spec rifle with FN barrel. That info is followed by the bullet info. The cell directly below the rifle and bullet designation indicates the powder charge used for that row (rung) of data. Finally, the RED numbers at the far right of each row indicate the difference in velocity between QL's predicted and the AVERAGE observed velocities <x>. The number to the right of that indicates the percentage difference between predicted and observed (average) velocities:

http://www.boogalootactical.com/pics/QL-Issues/9-22-Data/TAC.jpg

The worst of this bunch is seen in ROW 10 (TAC 26.9 gr.), and produced a 7.30% difference in predicted vs observed velocity.

Also noteworthy is that the difference between the "B-16" and the "M-S 16" rifles is really small. Furthermore, TAC @ 26.9 gr. seems to show a high spike in velocity across both rifles, but when the charge is increased to 27.3 gr. the difference spike seems to wane. Unfortunately, I was not able to get a full 10 shot reading from the M-S 16 rifle for the 27.3 gr. TAC load so that claim could be debated..


Next up was the BLC-2 ladder.

I decided NOT to shoot BLC-2 through both rifles since the previous testing indicated a variation between rifles that I would call negligible. Instead I focused on getting the data from the B-16 rifle (Satern/Wylde) exclusively.

The chrono data is seen below:

http://www.boogalootactical.com/pics/QL-Issues/9-22-Data/BLC-2.jpg

Again, you can see that the predicted and observed velocities are within 5% which is a good thing as far as I am concerned, but I would love to hear some feedback from those of you who have an educated opinion on all of this. It is my understanding that powder manufacturers are required to re-designate a particular powder if Ba (difference) values exceed 10%. I am wondering how many of them actually adhere to this standard? Experience from my previous outing would indicate that Accurate ignores this rule.

Finally, here is the data from Ramshot X-Terminator:

I used the same (B-16) rifle for the test, and oddly enough, the observed velocity was BELOW the predicted velocity by a little bit. I would call this particular test a near perfect prediction from QL for this particular load:

http://www.boogalootactical.com/pics/QL-Issues/9-22-Data/PRVI-X-Term.jpg

Things to consider:

(1) Every single cartridge referenced in this test was loaded during the same Friday evening (the day before the test).
(2) Every single cartridge referenced in this test was prepped exactly the same way on the RCBS case prep station.
(3) Every single cartridge referenced in this test was loaded on the same press (Dillon 1050), using the same powder measure, scale, calipers, etc.
(4) ALL cases used in this test were trimmed to 1.754" +/- .002" . Any case found to be outside the (+.002" / -0.000") was rejected and not used.
(5) ALL projectiles were individually weighed to fall within a .1 gr. tolerance.

YES it took me several hours to do all of this, but I wanted good data and strive'd to eliminate as many variables as I could.

It would be nice to hear what you think about how to get closer to achieving observed vs predicted velocity nirvana. Where do I go from here?

Thank you for your input.

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918v
September 23, 2012, 05:56 PM
Since no two barrels shoot the same, how do you expect a computer program to do better than 5%?

Andrew Leigh
September 23, 2012, 06:33 PM
A mate of mine cross checks my loads with quickload and generally we are within 10fps.

A general observation is that you may have wanted to have the chrono further away from the barrel. 10' does not sound like enough and you could be getting erronius reading. What does your manual say the distance should be?

jjjitters
September 23, 2012, 06:53 PM
There is also another variable, how accurate is you crono? Just another thing that "could" be in error+/- 2-3%.
Now get another lb of each powder from a different lot # and see how the differences are.

All in all I would say it is pretty good, you can change your barrel friction coefficiency or another variable(true bullet dia,true groove/bore dia of barrels ect..) to "tune" your QL into what YOUR guns do, then it may be even more accurate for many more powders.


When I loaded my gun data in I put in what my barrels slugged at and such.Any of those QL uses defaults and it adds up to little variences in predictions.

Boogaloo
September 23, 2012, 08:29 PM
Since no two barrels shoot the same, how do you expect a computer program to do better than 5%?

Thank you for your contribution, however this test had nothing to do with comparing the differences between barrels. The 2 different rifles were used to see if there was in fact a significant variation in observed velocity using the same load only as a frame of reference for me personally. I was also curious to see if the differences in chambers between the 2 rifles (Wylde and NATO) would produce significantly different velocities

The test and this thread were produced to try and narrow the gap between predicted and observed velocities using Quickload. I was hoping for feedback along those lines.

A mate of mine cross checks my loads with quickload and generally we are within 10fps.

A general observation is that you may have wanted to have the chrono further away from the barrel. 10' does not sound like enough and you could be getting erronius reading. What does your manual say the distance should be?

Thank you as well for your contribution. The manual for the CED M2 chrono states 7-10 feet for pistol and 10-12 feet for "high powered rifle" . I don't consider the AR15 to be a "high powered" rifle, so 10 feet seemed logical.
High Powered rifles (to me) start at .308 and go up from there.

There is also another variable, how accurate is you crono? Just another thing that "could" be in error+/- 2-3%.
Now get another lb of each powder from a different lot # and see how the differences are.

All in all I would say it is pretty good, you can change your barrel friction coefficiency or another variable(true bullet dia,true groove/bore dia of barrels ect..) to "tune" your QL into what YOUR guns do, then it may be even more accurate for many more powders.


When I loaded my gun data in I put in what my barrels slugged at and such.Any of those QL uses defaults and it adds up to little variences in predictions.

Thank you as well sir.
I can only assume the CED M2 is a reasonably accurate chrono. I also have the infra-red sky screens, and employed them for this test to further reduce error or sun direction anomalies. Hopefully it is in the ballpark as far as accuracy is concerned.

I have some slugging plugs on the way and will slug all of my rifles as soon as they arrive so that I can enter that data into QL.

I intend to play with a few things in QL using the observed data and the loads indicated in this thread to see if I can identify any variable(s) which may produce/predict the observed velocities from this test.

Thanks again to everyone who replied!

918v
September 23, 2012, 09:01 PM
The test and this thread were produced to try and narrow the gap between predicted and observed velocities using Quickload. I was hoping for feedback along those lines.


What I was trying to say is that your two barrels are a statistically inadequate sample to make a valid comparison between QL and actual velocity and pressure. If you shot your loads through my gun, they might end up within 1% of QL's prediction. There will always be a margin of error due to this simple fact that no two barrels are alike.

kelbro
September 24, 2012, 12:35 AM
Did you try re=running the predictions without using boat-tail on the bullet type?

Did you go back and weigh the cases for the outliers?

Did you sort your bullets by weight?

You are trying to apply benchrest calculations to mil-spec brass and plinker/varmint bullets. Based on those items, your numbers don't look too bad.

I have 8 Dillon powder measures set up on different toolheads. They are pretty consistent but not lab quality.

Boogaloo
September 24, 2012, 01:45 AM
What I was trying to say is that your two barrels are a statistically inadequate sample to make a valid comparison between QL and actual velocity and pressure. If you shot your loads through my gun, they might end up within 1% of QL's prediction. There will always be a margin of error due to this simple fact that no two barrels are alike.

Ok.. I understand.
It will be nice to get these barrels slugged and enter that data. I will re-run the charges from this load through QL and see if the numbers change.
I knew going in that there would always be a margin of error, but I tend to geek out a bit and really like to try and make the lines meet in the middle so to speak. Thank you again for participating. I do really appreciate it!


Did you try re=running the predictions without using boat-tail on the bullet type?

Yes I did, and the numbers changed by a couple of FPS.

Did you go back and weigh the cases for the outliers?

No sir, I did not.

Did you sort your bullets by weight?

Yes sir, I mentioned that in the first post.

You are trying to apply benchrest calculations to mil-spec brass and plinker/varmint bullets. Based on those items, your numbers don't look too bad.

Yes, I know these are not match grade components. I am trying to wrap my head around QL so that when I do start loading bolt action cartridges, using expensive brass and expensive bullets, I will have a better handle on dialing in super accurate loads. I will probably trickle charge and go to much greater lengths than I am now when that time comes.. For now, I would like good repeatable results using the tools and components I listed.

I have 8 Dillon powder measures set up on different toolheads. They are pretty consistent but not lab quality.

Yeah, I have been battling Dillon powder measures for a few months now.
An example would be the .3-.4 gr. variations I get when trying to load VV N320 for my 9's. I have polished, cleaned, replaced, and generally messed around with 2 different Dillon powder measures trying to make them N320 friendly. I basically gave up and load Win WSF almost exclusively for 9mm action pistol rounds. It measures exceptionally well, and gives me great results for the nines. 4.9 grains of WSF gives me 1050 FPS, decent recoil and fantastically clean burning at that charge. I load it as high as 5.1 grains, but for action pistol, 4.9 grains is perfect (CZ SP01, Zero 125 gr. JHP).

I may have a recently new 4lb keg of N320 for sale here pretty soon if I can't make it work in the powder measures I have.

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