How to choose the "best" powder from the list given by QuickLOAD

G

Gawp

New member
Hi,

I've just bought QuickLOAD and I'm doing simulations for a .30-30 Win Subsonic load (with a 170 gr bullet). I'll shoot it in a Marlin 336 XLR 24" barrel.

I used the "Setup propellant table" feature to basically make QuickLOAD try all powders to get a velocity of 320 m/s (1050 fps), taking into account all the other parameters (bullet weight, barrel length, etc.).

I live in France, so here we can get only very few powder brands compared to the US. I can get the brands Vectan and Vihtavuori.

Below are the powders and charges that:
* QuickLOAD thinks would achieve the 320 m/s
* AND which are officially listed on the websites of the powders manufacturers to achieve SUPERsonic loads with a 170 gr bullet (link: https://www.vihtavuori.com/reloading-data/rifle-reloading/?cartridge=29)

5uGzLEw.png


Based on this table, which powder would you pick, and based on what characteristics, to be the safest possible (i.e. avoid blowing up my head or damaging my gun)?
 
I would probably use something like Unique or Green Dot. (bulky shotgun and pistol powders) I don't know what that translates to in VV and Vectan. In larger cases like .308 and .30-06, a lot of people use Red Dot for subsonic loads, but .30-30 has a smaller case so Red Dot might be a little too fast; that's why I went with Green Dot.

How about Vectan A1 or A0?
 
I don't like the look of those low percent case fills for any of them.
Click to expand...
Can you elaborate why? In case all powder is ignited at the same time and the pressure is above max?

I would probably use something like Unique or Green Dot. (bulky shotgun and pistol powders) I don't know what that translates to in VV and Vectan. In larger cases like .308 and .30-06, a lot of people use Red Dot for subsonic loads, but .30-30 has a smaller case so Red Dot might be a little too fast; that's why I went with Green Dot.

How about Vectan A1 or A0?
Click to expand...
Unfortunately I'm not sure what are these powders equivalent with VV and Vectan.

About Vectan A1: good question! I found data in a reloading book suggesting 0,50g of Vectan A1 for a 170 gr bullet (and a 508mm barrel) but... QuickLOAD gives 388 m/s (1273 FPS). So it's not anywhere near subsonic... any idea why? Is it QuickLOAD which is wrong? it's a big difference... :/
 
Does Quickload have A0 and A1 powders in its database? They should be roughly equivalent to Green Dot and Unique (I'm not sure how equivalent, or which is which) Put 1000 fps into QL and see what it predicts. Then ask yourself it if looks reasonable. (always ask yourself if the results look reasonable; that goes for anything in life.)
 
Gawp,

Unfortunately, you would be putting yourself and your gun at some risk using rifle powders at below about 60% of case fill. This can cause the powder to position itself in the case such that a larger surface area is exposed to ignition than is normal, and that can result in the powder burning like a faster burning powder, raising pressure. Every once in a long while it can greatly exceed the normal operating pressure of the gun. Frequently, it also ignites so poorly that it can leave a bullet stuck in the barrel of your gun, bleeding the rest of the gas pressure out around the case. In the best scenario, the pressure will be very erratic.

The best way to handle this is to use a faster powder. Faster powders can be loaded down to 30% case fill before hazards start to appear. You could, for example, use about 6.5 grains of N32C. Because of velocity variation, if you try this, I would pull a small tuft of polyester pillow ticking (stuffing) add insert it over top of the powder to hold the powder against the primer vent (flash hole).

If you would like to see how erratic the rifle powder pressures become, look on pages 52 and 53 of this old study showing the problem in the 30-06. You will see that below about 30 grains of powder (about 57% case fill) the pressures start to go over a span of over 3:1 in some instances. In a later article, in Handloader Magazine, the author explained this is actually a random distribution of a small number of samples, but that in the years after this study the got some less probable events a large number of standard deviations from the average and that could be as much as double the maximum chamber pressure of the cartridge.
 
Does Quickload have A0 and A1 powders in its database?
Click to expand...
They do, but it seems these two powders wouldn't be a good fit: A1 would require a very light charge (0.33g = 5.09gr, for a filling ratio of 23.4%), plus QuickLOAD isn't happy about the default "Shot Start Pressure" (250 bar) with this load and wants to lower it to 191 bar (I'm not sure what this means, but maybe there would not be enough pressure to push the bullet and it would get stuck in the barrel?).

Gawp,

Unfortunately, you would be putting yourself and your gun at some risk using rifle powders at below about 60% of case fill. This can cause the powder to position itself in the case such that a larger surface area is exposed to ignition than is normal, and that can result in the powder burning like a faster burning powder, raising pressure. Every once in a long while it can greatly exceed the normal operating pressure of the gun. Frequently, it also ignites so poorly that it can leave a bullet stuck in the barrel of your gun, bleeding the rest of the gas pressure out around the case. In the best scenario, the pressure will be very erratic.

The best way to handle this is to use a faster powder. Faster powders can be loaded down to 30% case fill before hazards start to appear. You could, for example, use about 6.5 grains of N32C. Because of velocity variation, if you try this, I would pull a small tuft of polyester pillow ticking (stuffing) add insert it over top of the powder to hold the powder against the primer vent (flash hole).

If you would like to see how erratic the rifle powder pressures become, look on pages 52 and 53 of this old study showing the problem in the 30-06. You will see that below about 30 grains of powder (about 57% case fill) the pressures start to go over a span of over 3:1 in some instances. In a later article, in Handloader Magazine, the author explained this is actually a random distribution of a small number of samples, but that in the years after this study the got some less probable events a large number of standard deviations from the average and that could be as much as double the maximum chamber pressure of the cartridge.
Click to expand...
Hi Unclenick! Indeed, I tried most of the Vectan and Vihtavuori powders in QuickLOAD and N32C seems to be the best fit: filling ratio = 40.5%, charge = 0.41g (6.33 gr), max pressure = 1114 bar (16,151 psi) for a resulting velocity of 317 m/s (1040 fps).

I also tried your trick you told me in my other thread to see what would happen if all the powder would burn at once, and the resulting pressure would be 1518 bar, which is well below the max CIP pressure of 3200 bar.

I have two questions about stuffing and the use of fillers:
* In the case where the pressure generated if the powder would all burn at once is unsafe (> max CIP pressure), then stuffing can be useful to prevent the powder from burning all at once by keeping it in place, right?
* In our case with N32C, stuffing will only help with having more stable/reproducible velocities, right?

Thank you so much for your very high quality and helpful answers Unclenick!
 
Gawp can you get explosia or lovex powder there? It’s Czech made and I would think would be available somewhere. I know they have quite the assortment, and if I recall correctly they have a powder almost akin to trail boss that is safe for reduced loads like what you are looking for.

Edit: found it, but I was wrong it is not much like trail boss. More like in between a magnum pistol powder and fast rifle powder, but safe for reduced loads. D060 lovex powder would be suitable. If you have access.
 
Last edited:
Gawp,

You understand correctly. The N32C can still light at different rates if it is spread out along the bottom side of the case rather than back against the flash hole, but it won't be dangerous. For the other powders, the tuft can prevent the dangerous peak pressure, but you still want to be careful because you have enough powder mass that it can be thrown forward with some force and occasionally you hear of chamber ringing resulting from shooting many loads like that. Also, the slower rifle powders require a certain amount of pressure in the case to maintain combustion through their deterrents in the presence of the combustion gases, so you may need to go to a magnum primer with them. Another discouraging factor for the slow powders is that with the percent of powder burnt in the barrel being so low, they will throw a lot of unburned powder out of the muzzle, which will tend to clog up a suppressor, assuming you are using one.
 
Update!

I just fired my first batch of cartridges that I've ever made!

I loaded the cases with 0,42 g (6,48 gr) of Vihtavuori N32C and a 170 gr bullet (Hornady 3060). Winchester LR primers.

Results with a chronograph:
* Bullet 1: 228 m/s
* Bullet 2: 247 m/s
* Bullet 3: 209 m/s
* Bullet 4: 218 m/s
* Average: 225 m/s

It's quite far from what QuickLOAD predicted (320 m/s).

What do you think? Is this okay? Can I safely add more powder (step by step) to reach 320 m/s (QuickLOAD seems okay with it)?
 
Last edited:
CAUTION: The following post includes loading data not covered by currently published sources of tested data for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

I'm used to QuickLOAD's velocity predictions being a little high because they are "fired" in ideal barrels. But your difference is over 300 ft/s and that is almost a third of the total. Did you elevate the muzzle to get the powder back over the flash hole? That an makes the pressure go to maximum. I will guess that your chamber is looser than a test barrel, and also that at these low pressures, you may lose some gas around the case (are the cases sooty?) and bore friction will be a factor.

I would raise the charge to 0.5 grams and see what velocity you get. It should still be well below maximum pressure for the 30-30. You could even creep up a little over that if you are watching carefully as you go.
 
I loaded the cases with 0,42 g (6,48 gr) of Vihtavuori and a 170 gr bullet (Hornady 3060). Winchester LR primers.

Results with a chronograph:
* Bullet 1: 228 m/s
* Bullet 2: 247 m/s
* Bullet 3: 209 m/s
* Bullet 4: 218 m/s
* Average: 225 m/s

It's quite far from what QuickLOAD predicted (320 m/s).
Click to expand...

Unless I'm reading the QL chart in post #1 wrong, 0,42 g (6,48 gr) of Vihtavuori is way undercharged from what QL recommended for 320 m/s.
 
I'm used to QuickLOAD's velocity predictions being a little high because they are "fired" in ideal barrels. But your difference is over 300 ft/s and that is almost a third of the total. Did you elevate the muzzle to get the powder back over the flash hole? That an makes the pressure go to maximum. I will guess that your chamber is looser than a test barrel, and also that at these low pressures, you may lose some gas around the case (are the cases sooty?) and bore friction will be a factor.

I would raise the charge to 0.5 grams and see what velocity you get. It should still be well below maximum pressure for the 30-30. You could even creep up a little over that if you are watching carefully as you go.
Click to expand...
I did the opposite actually: I was shooting standing up, the muzzle towards the ground. Indeed the cases are black around the case neck! More than usual I'd say?

Ok, I will try to slightly increase the charge to 0.5 gram!

Unless I'm reading the QL chart in post #1 wrong, 0,42 g (6,48 gr) of Vihtavuori is way undercharged from what QL recommended for 320 m/s.
Click to expand...
In post #1 I didn't post the data for N32C. It is 0.42 gram for N32C.
 
OP. I redid your load in GRT. I got the same results. I played around the parameters, and it was impossible to get muzzle velocity down to your measured figures, unless you grossly under charged the powder to below 3.5 grain. Assuming there was nothing wrong with your Chrono settings, the only explanation I can come up with is the load is indeed to light for the model to accurately predict the muzzle velocity.

N32C, also known as tin star, is quite similar to IMR trail boss, as far as l know. For trail boss they recommend starting with load ratio of 70%. Sound like you will need to experiment with your load to reach your target velocity. I agree with unclenick that you can up the powder charge, and before each shot raise the muzzle to settle the powder against the flash hole.

Another input for your consideration. You may want to use the heaviest bullet you can find for subsonic load, such as hornady 3090. That requires 7.5 grain of powder, and the load ratio is 52%.

-TL

Sent from my SM-N960U using Tapatalk
 
OP. I redid your load in GRT. I got the same results. I played around the parameters, and it was impossible to get muzzle velocity down to your measured figures, unless you grossly under charged the powder to below 3.5 grain. Assuming there was nothing wrong with your Chrono settings, the only explanation I can come up with is the load is indeed to light for the model to accurately predict the muzzle velocity.
Click to expand...
I think my chronograph is ok, it seems right for my pellets and my .22 LR. But indeed it's weird that QuickLOAD/GRT are way off here.

N32C, also known as tin star, is quite similar to IMR trail boss, as far as l know. For trail boss they recommend starting with load ratio of 70%. Sound like you will need to experiment with your load to reach your target velocity. I agree with unclenick that you can up the powder charge, and before each shot raise the muzzle to settle the powder against the flash hole.
Click to expand...
Indeed, I'm only at 50.3% right now with 0.51 gram of N32C. I took care to raise the muzzle vertically so that the powder is correctly against the flash hole! Below are the results!

Another input for your consideration. You may want to use the heaviest bullet you can find for subsonic load, such as hornady 3090. That requires 7.5 grain of powder, and the load ratio is 52%.
Click to expand...
Thanks, I'll keep that in mind if I can't achieve what I want with my 170 gr bullet.

-----------------------

So, here are the results of today!

First, I fired 5 of the manufactured cartridges I bought in a gunshop. They are advertised as subsonic (320 m/s they say), they use the same bullet as me (I copied them actually, a 170 gr Hornady 3060), the same case brand (Sellier & Bellot) and the same primers (I switched to CCI LR primers). Only the powder is different (they seem to use Vectan Ba10, I use Vihtavuori N32C).

* Bullet 1: 271 m/s
* Bullet 2: 221 m/s
* Bullet 3: 203 m/s
* Bullet 4: 211 m/s
* Bullet 5: 170 m/s (!!!)
* Average: 215 m/s (705 fps)
* Standard deviation: 33 m/s (108 fps)

Notice how big is the difference between bullets!

Then, I shot 5 of the cartridges I made today with 0.51 gram of N32C:
* Bullet 1: 245 m/s
* Bullet 2: 285 m/s
* Bullet 3: 280 m/s
* Bullet 4: 259 m/s
* Bullet 5: 278 m/s
* Average: 269 m/s (883 fps)
* Standard deviation: 15 m/s (49 fps)

It's much better, but I'm still quite under 320 m/s.

What do you guys think about adding 0.05 gram? The load would be 0.56 gram of N32C for 55.3% of filling.

Also, I was wondering: if QuickLOAD gives velocities which are so wrong, can we really trust it to give pressures which are correct and not blow up our guns?
 
Last edited:
I don't own quickload, but I have used GRT quite a bit. Most cases, except one or two with questionable powder model, the results have been almost right on. Of course all those loads are not super light loads like yours. To be honest, I don't feel comfortable doing what are doing myself. The load is just too light.

Yes I do trust the tool, but always with a grain of salt. Whenever possible I want to have secondary confirmation from a different source, a reloading manual perhaps.

To answer your question, I would agree to up the charge by 10%. I believe that will bring you to 290 m/s range. Another 5% will possibly bring you close to your target speed. Then you may want to rerun the sim on QL. You may see the difference getting closer.

-TL

Sent from my SM-N960U using Tapatalk
 
If you choose powders for which there is a measured example of both pressure and velocity, you often find the don't both match at once in QuickLOAD. Part of the reason is the "barrel" in QuickLOAD is ideal. Part of the reason is most people don't take the time to fix the details, like case capacity and bore cross-sectional area. But part of it is that its model bases the results on absolute pressure. In the measuring world, it is almost impossible to determine exactly what that pressure actually is. For example, the SS109 cartridge maximum average pressure measured 55,000 psi by U.S. copper crusher, almost 62400 psi by EPVAT channel transducer, and about 58,200 psi in a SAAMI-type conformal transducer. So the question that arises is which pressure do you think QuickLOAD should match? Pressure measuring has a lot of variables in it, so one needs to take it all with a grain of salt. SAAMI and the CIP allow considerable variation just among the individual rounds that you get an average pressure from for that reason. +15% for the highest pressure sample in the average for the CIP, and, by other criteria, about +18.3% for SAAMI. Second ten-shot samples are allowed to have a higher average by a couple of standard errors, and a higher number for samples taken from an aging lot also are part of the standard. Pressures are more like ballpark numbers than most people realize.


CAUTION: The following post includes loading data not covered by currently published sources of tested data for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

Gawp,

The data you supplied thus far indicates you gain about 48 fps for each gram of powder. This means, to reach 320 m/s you would need 6.14 grams of N32C. This still looks pretty safe in terms of projected pressure, even though QuickLOAD suggests it would be at 399 m/s, but, obviously, in your real gun it will not be that high. The odds are, therefore, that real pressure is lower in your gun.
 
Thank you for your answers!

Here are today's tests with 0.56 gram of Vihtavuori N32C!

* Bullet 1: 310 m/s
* Bullet 2: 313 m/s
* Bullet 3: 305 m/s
* Bullet 4: 306 m/s
* Bullet 5: 315 m/s
* Average: 310 m/s (1017 fps)
* Standard deviation: 3.9 m/s (13 fps)

I'm pretty happy with it! I think I may add 0.01 gram more (so the load would be 0.57 gram) but it's already great like this!

Thank you Unclenick and tangolima for the help!
 
Glad that it works out for you. QL or GRT are great tools, if you know their strengths and limitations. But as always, be very cautious when venturing outside then normal boundaries; loads either too light or too heavy. Be safe.

-TL

Sent from my SM-N960U using Tapatalk
 
You must log in or register to reply here.
Back
Top