Comparison of QuickLOAD versus GRT simulations for an unusual 9mm pistol loading

[JimGnitecki]

Comparison of QuickLOAD versus GRT simulations for an unusual 9mm pistol loading


Background of this comparison:

I have both the QuickLOAD (hereafter “QL”) and the Gordons Reloading Tool (hereafter “GRT”) simulation software packages, and used them the other day to compare their predicted results for an unusual 9mm pistol loading.

The results were “similar” but different than the “actual”, and also had enough differences in them to make me ask (a) why? and (b) are the differences typical for simulations?

I should mention right now that while I have decades of reloading experience, I am “new” to using simulation software. I bought QL and downloaded the most current free beta version of GRT, both within the past week. I am very early in my learning on both of them, and may well not be doing things correctly, or maybe just not making adjustments to the default software assumptions that an experienced user might know to make.

Also, the load I was developing is unusual. I want a fairly fast and very accurate 9mm 115 grain pistol load (1300 to 1350 fps ideally). Based on many years of successful usage, I prefer Vihtavuori powders. I also want to use the Hornady HAP 115g jacketed hollow point bullet, which is the same as the Hornady XTP bullet except the HAP’s hollow point does not have the “cuts” in it that promote expansion, as the HAP is designed for Action Pistol competition where no chance of a misfeed can be tolerated.

The Vihtavuori load table for 9mm shows the following data for a combination of bullet and powder that comes very close to meeting my objectives:

Caliber 9mm

OAL = 1.142”

Primer = Small Pistol

Case brand = Lapua

Powder = Vihatvuori 3N38 with minimum = 7.2 grains and maximum = 8.7 grains (compressed)

Muzzle velocity out of a 4” barrel supposedly was 1181 fps at 7.2g and 1401 fps at 8.7 grains.

Bullet = Berry´s 115g HB RN TP


This load implies that about 8.0 grains might deliver a bit over 1300 fps. I communicated with a well known ballistics author who did some QL simulations on this load, and assured me that substituting the HAP bullet for the Berry’s should produce lower pressure than the Berry’s load since the HAP bullet is shorter than the Berry’s bullet. Thus if I use the same OAL, the max pressure should be lower.

Note that this load uses VV 3N38 powder, which is a slow burning pistol powder. VV recommends it to Action Pistol competitors who need high velocity AND enough residual gas pressure past the muzzle to effectively operate a compensator. A slow burning powder can achieve both objectives by limiting peak pressure while still generating enough bullet velocity in the barrel, and enough gas velocity beyond the muzzle to operate the compensator.

Before I ever got QL and GRT, I had already tested the load at 7.2, 7.4, 7.6, 7.8, and 8.0 grains. The 7.2 grain load was not good. The 7.4 through 7.8 grain loads produced gradually improving accuracy. The 8.0 grain loading produced the best accuracy, and also the highest velocity at 1324 fps. Its Standard Deviation was just 10.0. The best 5-shot group at 25 yards, off a suboptimal sandbag and with my 70 year old eyes looking through progressive bifocals, was 1-3/8” but the best 4 in that group were just 13/16” (0.81”). This was fired out of my unmodified SIG P210 American Target pistol. Note that the 8.0 grain load is almost exactly between the minimum and maximum loads in the VV load table, for the 115g bullet and 3N38 powder. So, it’s not “hot” and not “weak” either.

Note that since the max load VV recommended was 8.7 grains, it would be logical to assume that that loading either hit, or was close to, either the SAAMI or CIP limit of around 34,000 psi. So I figured that at 1324 fps versus the 1401 fps shown for the 8.7g load, my load must be somewhere under 34,000 psi but not too far below since 1324 is not that far from 1401 fps.

So, already knowing I had a good (maybe even great) load, but curious about what peak pressure I was producing to get it, I ordered QL and then found out about the free beta GRT and downloaded that too.

In dojng the required inputs, I entered my actuals, wherever i had them, in place of the default values. That means that I used my actual (Hornady) case internal volume, my actual case height, my actual bullet length, actuaL OAL, etc. Then, I ran the simulation for each software package.


My Results:

The key differences that I, as an “amateur” in using simulation software, detected in the two results were:

Item / QL / GRT / abs diff / % diff / Actual (if available)

Max pressure / 22,972 psi / 25,181 / QL 2209 lower / QL 9.6% lower

Muzzle velocity / 1185 fps / 1249 fps / QL 64 lower / QL 5.4% lower / 1324 fps actual

Barrel time (10% Pmax to muzzle) / .552 ms / .5295 ms / QL .0225 ms higher / QL 4.2% higher

Percent of propellant burned / 75.49% / 70.3% / QL 5.2% higher / QL 7.4% higher

Ballistic efficiency / 23.5% / 26% / QL 2.5% lower / QL 10.6% lower

Load ratio / 98.7% / 101.8% / QL 3.1% lower / QL 3.1% lower



Questions prompted by looking at these differences one at a time:

Max Pressure:

Note that the max pressures differ by 9.6%.
- Is this typical for simulations, or is it because this is an unusual pistol load that only burns 70 to 75% of the powder before the bullet leaves the muzzle?

-Does this 23k to 25k psi pressure, compared to the SAMMI max for 9mm of 34,000 psi, surprise any of you more experienced simulation users? After all, with an actual velocity = 1324 fps, this IS a reasonably hot load for 9mm.


Muzzle Velocity:

Note that there is a 5.4% difference predicted by the 2 simulations.

Note also that the actual velocity (measured accurately by Labradar) is almost 9% higher than the average of the 2 simulations!

- Why?


Barrel Time (10% Pmax to muzzle):

There is a 4.2% difference between the 2 simulations.


Percent of propellant burned:

There is a 7.4% difference in the amount of propellant burned.

- Both of the simulations show a relatively low 70 to 75% burn. Is this because this is an unusual load with a slow powder designed to feed a pistol compensator lots of gas after the bullet has left the muzzle?


Ballistic efficiency:

Is the Ballistic efficiency simulation, either 23.5% or 26%, typical? Or is it low due to the unusual load?


Load ratio:

The Load ratio (i.e. percent of the available volume left in the case below the bullet that is actually used by the powder with this load) shows as 98.7% in QL and 101.8% in GRT. This correctly says that this 8.0 grains of VV 3N38 powder requires near or slightly over the available case volume under the bullet. i.e. it is near or actually a very slightly compressed load.

But, given that I did not use the “default” internal volume for a 9mm case with either QL or GRT, but instead carefully measured the ACTUAL volume via the “grains of water” test, this SHOULD have been exactly the same volume with both simulations.

The fact that it is not the same means that QL and GRT use slightly different powder density. Indeed, QL says it used a solid density of 1.51 g/cc, while GRT says it used the same value. So why is the load ratio different?

I am trying hard to learn how to properly use QL and GRT, and I would greatly appreciate it if some of you experienced load simulators could give me some guidance as to how to get my simulations closer to the actual results I get when I shoot the loads.

ANY help or advice would be appreciated.

I have attached screenshots for both QL and GRT showing my inputs and the results.

Jim G

 

[jonas66]

Totally out of my depth.
I'm in to listen and learn.

 

[MEHavey]

Did I see actual/chrono'd velocity in the OP ?

 

[fxvr5]

I have experience with QL but not the other software. Regardless, they both estimate their results. That's the key word; estimate. That's why you can't take the output too seriously. And this also makes comparisons between them a little questionable because they might or might not match what is actually occurring depending on the powder, bullet, etc. that is being estimated.

Also, no need to call the load 'unusual'. This almost sounds like this is a 'special' load which requires special analysis of the output. It doesn't. It's a regular load and does not require anything magical in data interpretation.

The reason the two softwares produce different results is because they differ in what values are being used to make the calculations. That's all.

You really can't take the output too seriously. The one thing to learn about this type of software is that they just estimate stuff based on the values used to make the calculations - which is up to the program designer. What you'll learn from pouring over the data and trying to make sense of it is that it's just estimations. They can be waaaaaay off. I mean really off. Some folks say QL does pretty well with rifle data, but I know that QL is hit or miss with pistol data.

You can look at Western Powder data where they give you the pressure they recorded and compare the output with the real world stuff. It will open your eyes! The QL software can be an interesting tool, but you wouldn't want to bet your life on the output.

Here's a recent article where the author uses QL to estimate pressure in a 9mm. You can look it over to see how he used it. https://www.shootingtimes.com/editorial/fast-9mm-loads/388612

I can also critique your use of only 5 shots for accuracy testing, too. See: https://www.ssusa.org/articles/2019/9/25/accuracy-testing-shortcomings-of-the-five-shot-group/

Note that this load uses VV 3N38 powder, which is a slow burning pistol powder. VV recommends it to Action Pistol competitors who need high velocity AND enough residual gas pressure past the muzzle to effectively operate a compensator. A slow burning powder can achieve both objectives by limiting peak pressure while still generating enough bullet velocity in the barrel, and enough gas velocity beyond the muzzle to operate the compensator.

Fast burning powders also have gas pressure to "operate the compensator". Just less pressure than a powder that uses more charge weight.

Questions prompted by looking at these differences one at a time:

Max Pressure:

Note that the max pressures differ by 9.6%.
- Is this typical for simulations, or is it because this is an unusual pistol load that only burns 70 to 75% of the powder before the bullet leaves the muzzle?

They are just estimates (using different values/algorithms), and have nothing to do with a powder that burns 70 to 75% of the powder before the bullet leaves the muzzle. Peak chamber pressure is reached after the bullet has moved about 1/2" (in many pistol rounds) so efficiency is related only to burn rate.

-Does this 23k to 25k psi pressure, compared to the SAMMI max for 9mm of 34,000 psi, surprise any of you more experienced simulation users? After all, with an actual velocity = 1324 fps, this IS a reasonably hot load for 9mm.

I'm neither surprised or care too much. It's good that the estimates are less than max, suggesting that for this powder and load the estimates aren't crazy or unrealistic. But that's all.

Muzzle Velocity:

Note that there is a 5.4% difference predicted by the 2 simulations.

Note also that the actual velocity (measured accurately by Labradar) is almost 9% higher than the average of the 2 simulations!

- Why?

Why? They're just estimates. It tells you that the software did a poor job of estimating speed with this powder and load. It might do better with a different powder and load. Or worse.

Barrel Time (10% Pmax to muzzle):
There is a 4.2% difference between the 2 simulations.

This does not matter. They're just estimates.

Percent of propellant burned:

There is a 7.4% difference in the amount of propellant burned.

They're just estimates. The software uses different values for its calculations. That's all. It has no meaning beyond that.

- Both of the simulations show a relatively low 70 to 75% burn. Is this because this is an unusual load with a slow powder designed to feed a pistol compensator lots of gas after the bullet has left the muzzle?

No.

Ballistic efficiency:

Is the Ballistic efficiency simulation, either 23.5% or 26%, typical? Or is it low due to the unusual load?

It's only related to the burning rate of the powder and barrel length. Nothing magical.

Load ratio:

The fact that it is not the same means that QL and GRT use slightly different powder density. Indeed, QL says it used a solid density of 1.51 g/cc, while GRT says it used the same value. So why is the load ratio different?

Different software using using different values/algorithms.

 

[Zak Smith]

One simulation is off by like 11% and the other is off by like 6%, judging by muzzle velocity. So neither one matches reality.

QL is useful for ballpark estimations and things like comparing what "should" happen in A vs. B vs C. But you have the actual results. Arguing why real-world results are wrong in vs. two simulations is missing the forest entirely.

 

[JimGnitecki]

Did I see actual/chrono'd velocity in the OP ?

Yes, the 8.0 grain load showed as average 1324 fps on my Labradar, with an SD of 10 fps.

Jim G

 

[Zak Smith]

FWIW, I have data from a long time ago using 3N37 showing 115's at 1344 at 7.8 grains 3N37.

 

[JimGnitecki]

I have experience with QL but not the other software. Regardless, they both estimate their results. That's the key word; estimate. That's why you can't take the output too seriously. And this also makes comparisons between them a little questionable because they might or might not match what is actually occurring depending on the powder, bullet, etc. that is being estimated.

Also, no need to call the load 'unusual'. This almost sounds like this is a 'special' load which requires special analysis of the output. It doesn't. It's a regular load and does not require anything magical in data interpretation.

The reason the two softwares produce different results is because they differ in what values are being used to make the calculations. That's all.

You really can't take the output too seriously. The one thing to learn about this type of software is that they just estimate stuff based on the values used to make the calculations - which is up to the program designer. What you'll learn from pouring over the data and trying to make sense of it is that it's just estimations. They can be waaaaaay off. I mean really off. Some folks say QL does pretty well with rifle data, but I know that QL is hit or miss with pistol data.

You can look at Western Powder data where they give you the pressure they recorded and compare the output with the real world stuff. It will open your eyes! The QL software can be an interesting tool, but you wouldn't want to bet your life on the output.

Here's a recent article where the author uses QL to estimate pressure in a 9mm. You can look it over to see how he used it. https://www.shootingtimes.com/editorial/fast-9mm-loads/388612

I can also critique your use of only 5 shots for accuracy testing, too. See: https://www.ssusa.org/articles/2019/9/25/accuracy-testing-shortcomings-of-the-five-shot-group/

Thanks for the response! I had heard that some users can get VERY close to actual results with QL or GRT, but maybe that is with rifle cartridges where the case volume is much higher and therefore less reflective of errors made in the reloading inputs or actual reloading.

On the 50-shot groups: I've read Brad Miller's article in Shooting times, and I get that. But what I do is fire at least 10 5-shot groups for a load I am considering (unless the first few groups show it is NOT worth proceeding further!). The 5-shot groups are easier to "read" and can also be readily compared to results shot by others (most magazine tests have a table of 5-shot groups fired at 25 yards with different factory and handloaded cartridges).

Jim G

 

[JimGnitecki]

One simulation is off by like 11% and the other is off by like 6%, judging by muzzle velocity. So neither one matches reality.

QL is useful for ballpark estimations and things like comparing what "should" happen in A vs. B vs C. But you have the actual results. Arguing why real-world results are wrong in vs. two simulations is missing the forest entirely.

Yes, I already know that the 8.0 grain laod is accurate, but I was mainly interested in finding out what the peak pressure is. I can't believe it is only 23,000 to 25,000, although I'd LOVE it if it is true!. That's over 10,000 psi below the SAAMI limit for normal, not +P 9mm ammunition. I would have expected something in the very high 20,000s - almost 30,000. But if it is truly 23 to 25 thousand, great! But now I'll never know for sure . . .

Jim G

 

[JimGnitecki]

FWIW, I have data from a long time ago using 3N37 showing 115's at 1344 at 7.8 grains 3N37.

Where did you find that load? It sounds like a "contender" for me. Vihtavuori's current online table doesn't have ANY 115g load that gets to 7.8 grains, or that gets to 1344 fps! The closest they now show is a Hornady XTP at 6.7 grains max that delivers 1305 fps! That is relevant to me, as the HAP bullet is = the XTP bullet withOUT the "cuts" in the hollow point jacket that the XTP has (because the HAP is intended for Action Pistol competition where a jam is a big issue). Was that from an older VV (or other source) load table? (I want to use only loads that are listed in reputable tables.)

Jim G

 

[Zak Smith]

I can't believe it is only

You don't know that. It's extremely unlikely considering the actual MV is faster than both simulations.

 

[Zak Smith]

Where did you find that load?

I didn't mean to imply I found it in a published book. It is actual data I recorded from an experiment 18 years ago. I suspect that I found published data that supported it, because I would have, but I don't have the references handy. Same set of experiments I went to 9.0 grains 3N37 with a 90gr JHP (1586 fps). Fun! No noted pressure issues.

(I want to use only loads that are listed in reputable tables.)

Good idea. But, and no offense, then why are you trying to justify a load using QL or the other program? Reality is reality. The book is the book. Simulation is simulation. What happens with your components in your gun is also unique.

If we are basing this on the book, then what do you do when you get a MV that is higher than the book MV by a noticeable amount-- which it is.

 

[JimGnitecki]

. . .

If we are basing this on the book, then what do you do when you get a MV that is higher than the book MV by a noticeable amount-- which it is.

No, my MV is NOT higher than the VV load table. Remember your post talked about 3N37, not 3N38. The maximum load charge i quoted in reply was for the 3N37, not my 3N38. The 3N38 load table says you get 1401 fps if you load the maximum load of 8.7 grains. It also says that you get 1181 fps at the 7.2 grain minimum loading.

My 8.0 grain load is just under halfway (47% actually) between 8.7 and 7.2 grains, so the 1324 fps I actually got as an average fps with the Labradar seems "reasonable". Especially since 47% of the difference between 1401 and 1181 is 0.47 x (1401-1181) = 103 fps. So 1401 - 103 = 1298, and we know that as a general rule, when you reduce the charge, the % loss in fps is less than the % reduction in grains of powder.

VV itself says ""By staying 5 % below the maximum powder charge weight, pressures will be reduced by about 10 % while velocities will be only about 3 % lower than listed." My charge is 8% below maximum powder load and my actual fps is 5.5% lower than maximum fps. Again, seems reasonable.

Everyhitng seems reasonable in fact until BOTH QL and GRT give those low peak pressures and much lower velocity than actual. I guess they are indeed "only estimates" and rough ones at that.

Jim G

 

[vaalpens]

I have never used QL or GRT, but this thread is interesting.

But, given that I did not use the “default” internal volume for a 9mm case with either QL or GRT, but instead carefully measured the ACTUAL volume via the “grains of water” test, this SHOULD have been exactly the same volume with both simulations.

Looks like you measured the volume yourself. Was the case resized before the "grains of water" test?

It seems the starting values are not exactly the same:
115 gr Hrtenb FMJRN vs Hornady HAP 115gr
Seating depth: .148" vs .1486"
Case length: .751" vs .7513"

 

[Zak Smith]

No, my MV is NOT higher than the VV load table

Well, yeah, it is. You proved it in your second paragraph. The linearized MV at 8.0 should be 1298, but you shot 1324. So your actual firing event is happening at a higher pressure than the book data.

 

[fxvr5]

Just for giggles, if you want to see how far some powders are pushed in the 9mm, check out the loads for 9 Major at this source;

https://www.ssusa.org/articles/2020/4/28/accuracy-of-9-major-handloads/

Do not try those loads. They are meant only for guns specifically designed for 9 Major.

 

[JimGnitecki]

I have never used QL or GRT, but this thread is interesting.

Looks like you measured the volume yourself. Was the case resized before the "grains of water" test?

It seems the starting values are not exactly the same:
115 gr Hrtenb FMJRN vs Hornady HAP 115gr
Seating depth: .148" vs .1486"
Case length: .751" vs .7513"

Yes, both QL and GRT advise you strongly to use your known ACTUAL values versus the defaults, if you have the actuals.

GRT includes the HAP bullet in its database, while QL does not (has not been updated to reflect current bullets, powders, etc). So I had to use a bullet that QL includes that has identical dimensions and weights. The only apparent difference between that bullet and the HAP bullet is that bullet has a round nose versus the HAP's coned hollow point. That difference would affect EXTERNAL and TERMINAL ballistics, but not internal ballistics.

The seating depth is off only due to rounding by QL, and I tested making the COAL and seating depth different in both programs and the differences were indiscernible at SMALL changes in COAL and seating depth. (They DO get very sigificant if you make MUCH larger changes)

The case length difference was again QL rounding my input.

NO, the case was fired, but NOT resized. Both programs require that you use fired but not resized cases, as that more accurately reflects the actual "combustion chamber volume", since upon ignition, the case is supposed to stretch immediately against the walls of your specific firearm's chamber, meaning that the actual combustion chamber is larger than the pre-fired case.

Jim G

 

[MEHavey]

Hmmmm
QL is giving me 1,248 fps/29,000psi/5" for 3N38/8.0gr

 

[JimGnitecki]

Well, yeah, it is. You proved it in your second paragraph. The linearized MV at 8.0 should be 1298, but you shot 1324. So your actual firing event is happening at a higher pressure than the book data.

I respectfully disagree. Vihtavuori does not include actual velocities within the table other than the velocities for the "minimum" and "maximum" loadings, as the number of possible loadings within the recommended range is almost infinite (if you have an accurate enough scale and lots of time!) so it would be ridiculous for VV to even try to give MVs for all possible loadings!

In their OVERALL generic comments on reloading, that apply to ALL the pistol and rifle loads of every caliber included in the website, they merely give you the GENERIC guidance I quoted about how muzzle velocity is affected by a decrease in powder load from maximum. It is not meant to be a statement that will be EXACTLY correct for every different Vihtavuori powder in every different load, caliber, and firearm type!!

It's more an assurance that by staying below the maximum loadings, you will NOT lose as much velocity as you might have feared, because the relationship between grains of powder and muzzle velocity is NOT that when you reduce powder by "x" %, you lose an exactly equal % of MV.

My calculation of the 1298 fps value was merely to show you that there generic statement is upheld by my actual 1324 fps velocity being in the same ballpark as the roughly calculated 1298 fps based upon the generic statement.

Jim G

 

[JimGnitecki]

Just for giggles, if you want to see how far some powders are pushed in the 9mm, check out the loads for 9 Major at this source;

https://www.ssusa.org/articles/2020/4/28/accuracy-of-9-major-handloads/

Do not try those loads. They are meant only for guns specifically designed for 9 Major.

Yes I am familiar with some of the Major 9 loadings online, for example at the Brian Enos website. But I do not want a Major 9 load, as my pistol is a factory-stock SIG P210 (American) Target model, not a "built racegun"!

Jim G

 

[JimGnitecki]

Hmmmm
QL is giving me 1,248 fps/29,000psi/5" for 3N38/8.0gr

What EXACT values or default values did you input? I ask that because I am using the absolute most current version of QL and the values I inputed are listed above in my original post.

For some of the input values, a very small change makes a HUGE difference. For example, notice tat my fired Hornady case volume is notably larger than the "default" that QL uses for 9mm. And the COAL also has significant change effects, especially if you drop below COAL = 1.142", as the case, with the HAP bullet in it seated to COAL = 1.142" makes for almost exactly a 100% full case, which is ideal. If you go shorter, the combination of smaller combustion chamber AND compressed load means signficantly higher pressures.

Also, did you use the exact same bullet as I did? (Because QL has not been updated to have the Hornady HAP bullet in it nor even the XTP bullet which is identical except for its HP having "cuts" in it to promote expansion upon impact (despite the immense current popularity of both the hAP and XTP). I chose the bullet that appears closest in terms of important attributes. Which one did you use?

Jim G

 

[AJC1]

Can you take the measured data and force it to backwards calculate better data based on known information... one would think that making multiple corrections would make the output more valid. Your muzzle velocity measurement across several powder volumes should bring down the guess factors and tighten up your data sets.

 

[JimGnitecki]

Can you take the measured data and force it to backwards calculate better data based on known information... one would think that making multiple corrections would make the output more valid. Your muzzle velocity measurement across several powder volumes should bring down the guess factors and tighten up your data sets.

I'm afraid not. - in either of the 2 programs. The only data element I have from "outside the software defaults" , other than the ones i already entered, is the muzzle velocity, but neither program seems to allow you to enter that as a pre-determined result.

Both programs have a "parametric" search where you can specify some attributes (e.g. caliber, bullet weight, desired muzzle velocity) and the software will seek a powder solution that will get as close as possible to your desired targets. I could theoretically try that, but don't yet know hwo to do that even if I wanted to; I know I want to use a Vihtavuori powder, and the VV load tables, which are more reliable than QL or GRT, say thiat VV 3N38 is the best place to start.

But if I went that "search" route, I am pretty sure that each program would generate multiple non-Vihtavuori loads AND also include the same VV 3N38 predicted results just as they did when I instead fed in the known values. If they generated a different result for VV 3N38 than they already did, it would prove that the programs are inconsistent and flawed. So, no point in even trying that approach, unless I want to change powders, which I do not.

I totally agree that an "iterative" approach like you suggested could result in more accurate results, but neither program is apparently designed to support such a method.

Other QL and GRT users on various other forums and doing different cartridges have suggested that at this sort of point in using the software, and fater getting a result that does not match reality, you have to identify and change the default programmed value in the powder that is "off" at least for the batch of powder YOU have, until the results match reality. But I do not know, at least yet, what pwoder values I should be altering, and have been afraid to make any change that I might not be able to undo or to restrict to a specific "test case only".

I have chnaged the one powder value that I KNOW does not match my batch of powder: the load density. Both programs use 0.74 density of water, VV itself somewhere says 7.3, and my measured actual, done twice as a verification, shows 7.6 each time. So, I changed that value to 7.6. Did not make an appreciable difference since all that does is say that the powder occupies 2.7% less space in the case than it would at 7.4. Since the case is on the verge of being compressed, but not actually yet compressed, the difference in combustion is not noteworthy.

I suspect it is one of the other values, concerning energy content of the powder perhaps, or burn rate of the powder, that I would need to adjust, but I am too ignorant, and fearful, to just start playing with those numbers, without fully understanding what I am doing.

I was hoping that somewhere on this forum there is a reloader who (a) shoots pistol versus rifle, (b) has either QL or GRT or both, and (c) KNOWS which values to manipulate to make the simulation(s) more closely match reality. I figured that on this non-brand-specific forum, that has subforums for BOTH longarms and handguns, such a person might exist, might see my thread, and might be helpful or curious enough to try the simulation himself/herself and see what results are obtained when the "right" changes to default values are made.

Jim G

 

[Offfhand]

In my experienced comparisons, and that of other experimenters with whom I've discussed, the predictions of QL vs. actual range measurements vary much more with small capacity handgun calibers than with larger capacity rifle calibers... General assessment being that QL isn't worth bothering with for handgun calibers but often amazingly close for modern rifle calibers. Which is why I tend to put as much or more faith in the accuracy QL rifle predictions than loads listed in reloading handbooks by Hornady, Nosler, etc.

 

[JimGnitecki]

In my experienced comparisons, and that of other experimenters with whom I've discussed, the predictions of QL vs. actual range measurements vary much more with small capacity handgun calibers than with larger capacity rifle calibers... General assessment being that QL isn't worth bothering with for handgun calibers but often amazingly close for modern rifle calibers. Which is why I tend to put more faith in the accuracy QL rifle predictions than loads listed in reloading handbooks by Hornady, Nosler, etc.

I had heard that small & straightwall pistol cases were less accurate, but did not realize HOW much less accurate and useful. How well do either of them do with a .223 rifle cartridge, as that will likely be my caliber if I ever get around to buying a rifle again? That cartridge is bottlenecked but still not very large in terms of powder capacity. The larger calibers are simply too costly per round for my retirement budget!

Jim G