N150 in Quickload

[Boatschool02]

My Varget and RL15 estimates are within 20 FPS of LabRadar measured speeds.
However, QL projections for N150 are nearly 125 FPS low.
Just wondering what everyone is using for N150 powder attributes/variables?
Thanks in advance,

 

[XTR]

I don't use quickload, but here is what i have learned running it in F-TR .

I tried it for the first time about 5 yrs ago looking for an option slightly faster than H4350 for running 215s in a 308. I was starting with zero load data for the combination. What I found was that the burn rate charts appear to be wrong, and it didn't do what I was looking for in that application. N150 is much bulkier than Varget. It fills the case faster, but gr for gr it seems only slightly slower than Varget. In our F-TR 308s people running N150 are running loads that are in the range of zero to five tenths more for the same velocities with the same bullets and similar cambers compared to Varget.

For example, my 200.20x N150 load in a .168 freebore chamber in Lapua Palma brass is 44.3 running 2650ish.

If you are looking for it to work in QL I can't help. If you are looking for it to work in a 308 with 200.20x bullets in a 2013 FTR chamber I know at least 4 barrels that have run 44.3. A couple of those barrels have brought home hardware from national level matches.

 

[Boatschool02]

My limited experience is similar to yours.
Thus far, this lot of N150 is requiring +/- 0.2-0.7g more powder to match Varget velocities.
(Varget velocity/charge slope curve being more steep.)
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During the current hysteria, my drive time to a range is making QL an indispensable tool.
IF I'm going to dig into this, I'd like to become as proficient as possible.
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Thank you for sharing,

 

[Jdne5b]

fwiw, my 140 and N150 loads are identical and very close to Wade's, n140 giving 30fps more velocity than n150. I need a drop tube for both powders. Especially N150.

 

[Ned Ludd]

My Varget and RL15 estimates are within 20 FPS of LabRadar measured speeds.
However, QL projections for N150 are nearly 125 FPS low.
Just wondering what everyone is using for N150 powder attributes/variables?
Thanks in advance,

For clarification, exactly how did you generate these "estimates"? If you're talking about initially using as many accurate inputs as you have (i.e. barrel length, bullet OAL, case length, case volume, COAL, etc.), but then using the factory preset burn rate (Ba) to generate the prediction, I'd say you've been extraordinarily fortunate to generate predictions within 20 fps of measured velocity. That would likely mean that your specific Lot(s) of powder had burn rates very close to the preset values, something that doesn't always happen. Actual Lot-to-Lot powder burn rates can vary quite a bit. Further, burn rate will be directly affected by temperature and pressure, meaning a single Lot of powder can have different values for Ba depending on the cartridge and bullet weight actually used. After my initial experiences with different powders and the QL factory presets, I no longer make the mistake of assuming the preset burn rate will be close to my actual Lots of powder.

Once I have prepared an initial estimate as described above, I typically decrease the charge weight from a load already predicted to be under MAX pressure by about 2%, then load some rounds and obtain an average velocity for that charge weight. At that point, I will adjust the Ba value for the selected powder in QL until the "predicted" velocity exactly matches the "measured" velocity. I refer to this process as "calibration" of the program to my specific rifle setup. Once calibration has been done, QL velocity predictions are generally quite close to measured velocities in my hands, as long as they fall within a certain distance of the calibration charge weight.

Many of the the outputs of QL show up graphically as a perfect linear response. However, that is not what happens in the real world. Factors such as velocity and pressure tend to [effectively] behave in a linear manner only within a fairly narrow range, so it can be necessary to "calibrate" a given setup more than once if the initial calibration charge weight is a long way from where the tuned load will actually end up.

This is not the first time people have noticed that the QL files for VV powders seem a bit off. If you haven't already done so, calibrate your QL file by adjusting Ba until predicted velocity and measured velocity at the specific ambient temperature match exactly. That may fix the problem, at least within a certain range of the charge weight you are using. I have done that with in the past VV N140 and it seemed to work. However, if you calibrate the program to your specific setup by adjusting the Ba for N150, and then the pressure/velocity predictions still don't match up within about a half grain charge weight difference or so, it means there is something else off with the powder file beyond Ba that isn't allowing the predictions to mirror actual behavior. I have not tried to adjust any other powder file parameters beyond Ba. I also seem to recall that someone tried to contact VV about the specific powder data in QL files, but were not able to rectify the issue. Your best option is to try to adjust Ba and see if you can can get the program output to behave in a somewhat linear fashion in a region around the charge weight you're using.

 

[Boatschool02]

Thanks.
My first QL run of Varget with 130hyb in 6.5x47 was within 2 FPS. Good to know that may not be the norm. The more I think about variations in and between barrels, I see your point.
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123 scenars and the same lot of N150, referenced above, in the 6.5x47 case was low by 50FPS.
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Agree wholeheartedly with the nonlinearity, thus far, none of the estimates have held across 1-1.5 grain ladders.

I probably should have been more specific with my request:
- Is there an upper limit to adjusting Ba before the intent is lost?
- Is the heat/potential assumed to be accurate and held constant? (I played around with this as well, given n150 was so far off)
- In this particular instance, by the time I adjusted inputs enough to get the velocity close, the pressure was notably higher than either Varget or RL15 at the same easily achieved velocities, with no perceived pressure signs, causing serious doubts about adjusting Ba alone.
- If the velocity estimates are not linear, how much can you ever really trust Max pressure projections?

All told, I'm very impressed with the program and appreciate everyone's input.

 

[Ned Ludd]

I believe your 1st two questions are addressed in the QL manual. There is some information about adjusting Ba, and (I believe) a recommendation about the max amount you should ever change it, a recommendation I have exceeded regularly .

I have run N140 side-by-side with Varget and H4895 in .223 Rem. Even in reduced loads, the pressure WAS noticeably higher with the N140. It can happen and you can't ignore that just because it may seem odd. QL is a prediction program, nothing more. in general, the getter the inputs, the better the outputs. However, that is no guarantee that any output is ever "perfect" or necessarily 100% accurate and users have to accept that.

The reason non-linearity of velocity/pressure curves and MAX pressure predictions aren't typically a huge issue is that you're increasing charge weight until the output/prediction goes over the set maximum pressure (I use SAAMI MAX). Although the output response generally behaves in a linear fashion, we know that that isn't always what happens in the real world. For that reason, the predicted MAX may not be 100% correct if you "calibrated" QuickLoad a a charge weight well below that necessary to achieve MAX pressure. In fact, the closer your calibration charge weight was to the actual "MAX" charge weight, the better the prediction would be as I mentioned previously. Nonetheless, we don't always run charge weight/pressure up to MAX, and the pressures used in the proof testing process are typically much, much higher. Where it can become an issue is when you "calibrate" QL at a charge weight well below the node where you want to be, let's say something like a grain or a grain and a half or more below. QL will then predict you need to increase charge weight by "X" amount to actually hit that higher node. If you then go straight to that higher charge weight, you may well find that your velocity and pressure are actually quite a bit higher than QL predicted. Although it can sometimes be problematic, I don;t view it as a deal-breaker for two reasons. Number one - I always use the preliminary QL "calibration" to set up a charge weight test window; I do not jump all the way up to the hypothetical optimal charge weight up all at once, particularly if it is more than a few tenths or half a grain higher than the "calibration" charge weight. Number two - we can always choose NOT to fire loaded rounds when we observe pressure signs at a lower charge weight test increment.

The prediction software is not perfect. There are too many variables involved to expect a perfect prediction every time. Some times it will be closer out of the gate than others, but by testing and adjusting the program incrementally, you can generally avoid any safety issues. The more new variables involved in a particular load workup (i.e. new powder, new bullet, different freebore length, etc.), the more carefully I choose the test increments; smaller is generally better for safety reasons. These are idiosyncrasies of the system and the more you use it, the better you will get at understanding and working within them. Even in light of these idiosyncrasies, I find that QuickLoad can expedite the reloading process. It in no way completely eliminates testing, nor does it preclude evaluating actual test results. But I find it a useful tool to minimize the number of loaded rounds I have to test and therefore it allows me to find the load with a little bit less effort.

 

[Laurie]

I've found QL predictions for N150 to be reasonably good for some cartridges / bullets but way out in others, specifically 308 Win with heavier bullets. If you relied on QL alone, you'd likely not even consider this powder as an option.

With N160 in cartridges like 260 Rem and 7-08 I consider QL to be considerably worse using the default burning rate value (in QL v3.6). I'll knock around 5,000 psi off the ceiling for my initial pressure / functioning loads, eg choose a charge weight that produces ~53,000 psi estimated instead of the 57-58,000 initial ceiling I'd use if I trusted the program. N165 predictions conversely in cartridges like 284 Win are usually reasonably close. I'd agree too with @Ned Ludd that Viht's printed burning rate charts are often well out for some of its powders - but Hey what's different here from most other burning rate charts?

I've seen it stated on this forum that QL's latest version (v3.9) has changed many burning rate default values. Whether that is true and/or it includes Viht grades I don't know. When I upgrade my hardware soon and start using Windows 10 I think I'll get v3.9 as apart from anything else my current one is now badly outdated and short of new bullets and powders, so I'll be able to check whether N150 remains as now or not.

 

[Boatschool02]

Laurie,
Thanks.
In my current application, N150 is 160-170 FPS slow (below predicted) compared to measured speeds across a 1.6 grain spread. So much so that it would take 90K pressure via Ba increase to match reality.
Actual velocities are 30-40 FPS below Varget/RL15, grain for grain, at charge weights I consider comfortably safe.
The N150 extreme spreads are impressively lower than other powders I've tested and it cleans far better than Varget/RL15.
You're right. Based on QL alone, I would never have tried it or potentially have been unsafe if actually testing a 100% fill load at a predicted (but now obviously incorrect) 62,700PSI.
-
In cases like 6.5x47, Lapua Palma, and ADG magnums where excessive pressure signs may be delayed, it would be really nice to have better numbers for this powder.

 

[Ruger15151]

I'm new to QuickLoads as well. My current 308 Varget load is about 100 fps and a pressure of 58646psi. If I bump up the burn rate to true my actual velocity, The pressure jumps to 70108 psi.

Do I assume that this new pressure is somewhat accurate because the velocity is now accurate? I'm confused because there are several factors that could be causing increased velocity... dirty barrel, high altitude, faster barrel, ...etc.

Besides great knowledge shared on this forum, is there another knowledge base that can clarify some of these questions?

 

[Straightshooter1]

I'm new to QuickLoads as well. My current 308 Varget load is about 100 fps and a pressure of 58646psi. If I bump up the burn rate to true my actual velocity, The pressure jumps to 70108 psi.

Do I assume that this new pressure is somewhat accurate because the velocity is now accurate? I'm confused because there are several factors that could be causing increased velocity... dirty barrel, high altitude, faster barrel, ...etc.

Besides great knowledge shared on this forum, is there another knowledge base that can clarify some of these questions?

MORE detail needed . . . like: What's your actual average velocity? COAL? Weighting Factor? Barrel Length? Which bullet? Which brass (brass capacity)?

 

[Dgd6mm]

I'm new to QuickLoads as well. My current 308 Varget load is about 100 fps and a pressure of 58646psi. If I bump up the burn rate to true my actual velocity, The pressure jumps to 70108 psi.

Do I assume that this new pressure is somewhat accurate because the velocity is now accurate? I'm confused because there are several factors that could be causing increased velocity... dirty barrel, high altitude, faster barrel, ...etc.

Besides great knowledge shared on this forum, is there another knowledge base that can clarify some of these questions?

What other defaults have you changed, if any?

 

[Ned Ludd]

I'm new to QuickLoads as well. My current 308 Varget load is about 100 fps and a pressure of 58646psi. If I bump up the burn rate to true my actual velocity, The pressure jumps to 70108 psi.

Do I assume that this new pressure is somewhat accurate because the velocity is now accurate? I'm confused because there are several factors that could be causing increased velocity... dirty barrel, high altitude, faster barrel, ...etc.

Besides great knowledge shared on this forum, is there another knowledge base that can clarify some of these questions?

Ruger15151 - I would be very concerned if QL was telling me my .308 Win load with Varget was running 70K psi. It's not just a safety issue, it's also that you may be killing your brass well before its time, among other things. A main reason for using a program such as QL is to obtain the best possible predictions about a given load and/or modifications to an existing load that you may want to try. If the way you are using QL is generating predicted velocity that is ~100 fps off the actual value, something is wrong. Hopefully, the load is not really running at 70K psi, but you will need to play with it in order to determine that. QL is capable of generating much more accurate predictions than +/- 100 fps, but requires the best possible inputs and regular updating of files in order to do so.

I generally start on a new rifle/barrel/load development using the factory preset burn rate (Ba). I input all the actual measured inputs, including barrel length, bullet length, COAL, case length, case volume, and temperature. I then increase charge weight in the program until I find predicted MAX pressure. Again, this is using the factory preset burn rate (Ba) with all other inputs being actual measurements. I then drop the entered charge weight from MAX by about 2-3% and see how it looks. The idea is to find a reduced charge weight that generates a prediction well below MAX pressure, but that is not stupidly low compared to where you will likely end up. The whole reason for this is safety, in that the preset burn rates may or may not be accurate for a given cartridge/bullet/powder/primer. Thus, I choose a reduced charge weight using the factory preset burn rate that will not be over MAX pressure, even if the preset burn rate is off by a fair amount.

At this point I load up about 10 rounds, including a few foulers, go out to the range, and obtain actual velocity data for the reduced load. Back at home, I update any inputs if needed (especially temperature), then adjust the Ba value until the predicted velocity for the reduced charge weight exactly matches the average velocity I actually measured for that specific charge weight. Now the program has been "calibrated" to my specific setup and Lot# of powder. Within a certain range of charge weights, the predictions using the "calibrated" software should be very good. The farther away from the reduced calibration load you have to go, the farther off the predictions can get. This is because QL treats a number of outputs as being linear, when in reality they are not. It's not really an issue once you have calibrated the program, because you can easily "re-calibrate" it every time you obtain new velocity data. I update an existing QL file every time I generate more velocity data, changing any inputs necessary, such as temperature, etc., re-tweak the burn rate (Ba) so predicted velocity matches actual measured average velocity for a given charge weight, then save the file with a new name/date. That way, you will usually have predictions generated under a range of atmospheric conditions, as well as always having the output latest iteration of the load you are working with.

 

[Ruger15151]

Ned

Thank you for your detailed response.

I have only been using QL for a couple of weeks and reading as much information as I can as to how to best use this tool.

My process follows the one you have explained exactly. My test was with the following variables:

308 1:9 twist 26 in barrel
Varget 43.8 grs
Berger 185 Hybrid Target @ 2.948 COL
Lapua SRP @ 2.005
70 degrees

The predicted velocity is 2641 and the max chamber pressure of 58549 psi.

The actual measured velocity with my Labradar with this load is 2742 fps.

When I true the BA to .6835, the max chamber pressure is 69756

However, I have none of the usual pressure signs like flattened primers, ejector marks, or heavy bolt lift.

Should I ignore the "trued" max chamber pressure and use the tool to predict velocity and OBT?

I have been shooting this caliber and load for some time and get satisfactory brass life and barrel life. Therefore, I am confused as to how reliable a tool QL really is.

 

[Straightshooter1]

I have only been using QL for a couple of weeks and reading as much information as I can as to how to best use this tool.

My process follows the one you have explained exactly. My test was with the following variables:

308 1:9 twist 26 in barrel
Varget 43.8 grs
Berger 185 Hybrid Target @ 2.948 COL
Lapua SRP @ 2.005
70 degrees

The predicted velocity is 2641 and the max chamber pressure of 58549 psi.

The actual measured velocity with my Labradar with this load is 2742 fps.

When I true the BA to .6835, the max chamber pressure is 69756

However, I have none of the usual pressure signs like flattened primers, ejector marks, or heavy bolt lift.

Should I ignore the "trued" max chamber pressure and use the tool to predict velocity and OBT?

I have been shooting this caliber and load for some time and get satisfactory brass life and barrel life. Therefore, I am confused as to how reliable a tool QL really is.

For my lot of Varget I use a BR of .6613 and even with that QL shows pressure well above max (67,931 psi). And I see that QL shows your case filled to 102.8%, which suggests you've got somewhat of a compressed load and that'll boost presser/velocity up as well and QL will not automatically account for that. So, like Ned mentions, I'd load up a few (like 10 rounds) with a lighter load that get you just under 100% fill and get chrono reading on them and see what QL's BA is for those velocities.

The only other thing I'd double check is that average velocity you got with your Labradar. Typically, Labradar is very accurate. But I'd try and use someone else's for a few rounds and see if there is any significant difference, just to confirm that your particular chrono is giving you accurate readings.

It's not unusual that one will not get pressure signs like flattened primers, ejector marks, or heavy bolt lift even though QL shows the load to be well over pressure. I've experienced that myself (also having compressed loads with my Juggernauts) and just didn't feel comfortable shooting with that much pressure just to get a little more velocity.

 

[Ned Ludd]

Ned

Thank you for your detailed response.

I have only been using QL for a couple of weeks and reading as much information as I can as to how to best use this tool.

My process follows the one you have explained exactly. My test was with the following variables:

308 1:9 twist 26 in barrel
Varget 43.8 grs
Berger 185 Hybrid Target @ 2.948 COL
Lapua SRP @ 2.005
70 degrees

The predicted velocity is 2641 and the max chamber pressure of 58549 psi.

The actual measured velocity with my Labradar with this load is 2742 fps.

When I true the BA to .6835, the max chamber pressure is 69756

However, I have none of the usual pressure signs like flattened primers, ejector marks, or heavy bolt lift.

Should I ignore the "trued" max chamber pressure and use the tool to predict velocity and OBT?

I have been shooting this caliber and load for some time and get satisfactory brass life and barrel life. Therefore, I am confused as to how reliable a tool QL really is.

I think that QuickLoad is telling you that load is very hot. You're getting the same velocity from a 26" barrel that most F-TR shooters using 185 Hybrids get from a 30" or longer barrel. I also ran the numbers in QL using a somewhat "average" case volume value of 56.29 gr for Lapua Palma brass and got essentially the same pressure numbers you did. Initially, 43.8 gr of Varget didn't catch my attention, or seem like a stupidly hot load given your COAL. Nonetheless, getting the same velocity out of a 26" barrel (2742 fps) that others typically get from a 30" barrel is pretty telling, not to mention that it is also over 100 fps faster than the velocity of 2641 fps predicted at a very reasonable working pressure of 58.5K psi.

FWIW - .308 Win SRP brass is capable of withstanding much higher pressure than standard LRP brass, and for a greater number of firings. Although issues such as flattened primers, ejector marks, and heavy bolt lift can indicate high pressure and should never be ignored, they are not always the most reliable or accurate pressure indicators. Putting these two observations together, it is entirely possible/likely that QL's pressure predictions for that load are spot on. There is no way I can actually confirm that beyond any doubt over the internet, but I'd pay very careful attention to what the program is telling you.

 

[Ruger15151]

I think that QuickLoad is telling you that load is very hot. You're getting the same velocity from a 26" barrel that most F-TR shooters using 185 Hybrids get from a 30" or longer barrel. I also ran the numbers in QL using a somewhat "average" case volume value of 56.29 gr for Lapua Palma brass and got essentially the same pressure numbers you did. Initially, 43.8 gr of Varget didn't catch my attention, or seem like a stupidly hot load given your COAL. Nonetheless, getting the same velocity out of a 26" barrel (2742 fps) that others typically get from a 30" barrel is pretty telling, not to mention that it is also over 100 fps faster than the velocity of 2641 fps predicted at a very reasonable working pressure of 58.5K psi.

FWIW - .308 Win SRP brass is capable of withstanding much higher pressure than standard LRP brass, and for a greater number of firings. Although issues such as flattened primers, ejector marks, and heavy bolt lift can indicate high pressure and should never be ignored, they are not always the most reliable or accurate pressure indicators. Putting these two observations together, it is entirely possible/likely that QL's pressure predictions for that load are spot on. There is no way I can actually confirm that beyond any doubt over the internet, but I'd pay very careful attention to what the program is telling you.

Thanks Ned. Prior to having Quickloads, I developed loads by starting in the middle load range, loading a single round, then increasing .5 grains until I started seeing pressure signs.... flat primers, ejector marks, heavy bolt lift, case expansion near the head of the case...etc... Then I would back off 1-1.5 grains and load ladders until I found a velocity plateau. Its quite possible that my 308 Lapua Palma brass has been masking the pressure signs. I have plugged in some additional loads ( after trueing the burn rates) and QL says they are all over pressure.

Since playing with QL, I have developed a good load with Varget that shoots around 2620 fps at safe pressures.

OBT is also a new concept for me. In the past, I have adjusted group size through seating depth. Now, I also run one of Cortina's Tuner breaks which is very effective. Is focusing on OBT less important to load development when using a tuner?

 

[Ned Ludd]

Thanks Ned. Prior to having Quickloads, I developed loads by starting in the middle load range, loading a single round, then increasing .5 grains until I started seeing pressure signs.... flat primers, ejector marks, heavy bolt lift, case expansion near the head of the case...etc... Then I would back off 1-1.5 grains and load ladders until I found a velocity plateau. Its quite possible that my 308 Lapua Palma brass has been masking the pressure signs. I have plugged in some additional loads ( after trueing the burn rates) and QL says they are all over pressure.

Since playing with QL, I have developed a good load with Varget that shoots around 2620 fps at safe pressures.

OBT is also a new concept for me. In the past, I have adjusted group size through seating depth. Now, I also run one of Cortina's Tuner breaks which is very effective. Is focusing on OBT less important to load development when using a tuner?

That's a good question. You will find a lot of different opinions regarding Optimized Barrel Time here. Some swear by it, some think it is not valid, or at least not well-explained and not consistent with different rifles/loads. In my hands, the OBT Nodes as listed for different barrel lengths in Chris Long's Table have proven to shoot quite well. In fact, when I first started reloading, I didn't have QuickLoad or any knowledge about barrel occupancy times at all. Nonetheless, I later went back and documented using QL the first three loads I had previously worked up for different rifles/calibers. Every single one of them was spot on the barrel time predicted for Node 4 for a 30" barrel. In my opinion, there is no way that is mere coincidence, as there were three different loads involved, with three different bullet weights, two different powders, and two different rifles. So I think there is something to the OBT Nodes, but the provided explanation involving longitudinal shockwaves through the barrel steel is a little hard to digest. My gut feeling is that OBT Nodes may have more to due with traditional barrel timing with respect to barrel harmonics, but that is merely a feeling and I have no way to prove that conclusively.

IF (and that can sometimes be a big "if") you can hit a particular OBT Node with a given powder, bullet weight, and barrel length, there is no good reason not to evaluate load performance using QuickLoad and barrel times. If a load doesn't look good within a reasonable range of barrel times surrounding the purported OBT Node, then you have to keep looking. However, when it works, it seems to be pretty obvious, at least in my hands. One of the major values of using a program such as QL is to be able to use the barrel time output for the purpose of targeting OBT Nodes. In that event, the use of the software can certainly facilitate and expedite the reloading process. If you cannot hit a given OBT Node due to barrel length, bullet, or powder selection, the program is somewhat less useful, although having solid pressure/temperature predictions is never a complete waste of time, IMO. The good news is that reloading programs are not essential for developing solid loads. They can sometimes help, but you can reach the same endpoint regardless of whether you use a reloading program or not. So I try to take advantage of their use to facilitate load development when/if it appears that a given load will fall very close to a predicted OBT Node, but am not dependent on the software when the load clearly isn't going to be close to an OBT Node. Another benefit to having QuickLoad is that you make very good predictions as to what barrel length you need with a given powder and/or bullet weight to actually target a specific OBT Node. That is not necessarily always helpful with an existing setup, but can be very useful to help you choose barrel length, freebore length, etc., when deciding on specs for a new barrel.

 

[Ruger15151]

That's a good question. You will find a lot of different opinions regarding Optimized Barrel Time here. Some swear by it, some think it is not valid, or at least not well-explained and not consistent with different rifles/loads. In my hands, the OBT Nodes as listed for different barrel lengths in Chris Long's Table have proven to shoot quite well. In fact, when I first started reloading, I didn't have QuickLoad or any knowledge about barrel occupancy times at all. Nonetheless, I later went back and documented using QL the first three loads I had previously worked up for different rifles/calibers. Every single one of them was spot on the barrel time predicted for Node 4 for a 30" barrel. In my opinion, there is no way that is mere coincidence, as there were three different loads involved, with three different bullet weights, two different powders, and two different rifles. So I think there is something to the OBT Nodes, but the provided explanation involving longitudinal shockwaves through the barrel steel is a little hard to digest. My gut feeling is that OBT Nodes may have more to due with traditional barrel timing with respect to barrel harmonics, but that is merely a feeling and I have no way to prove that conclusively.

IF (and that can sometimes be a big "if") you can hit a particular OBT Node with a given powder, bullet weight, and barrel length, there is no good reason not to evaluate load performance using QuickLoad and barrel times. If a load doesn't look good within a reasonable range of barrel times surrounding the purported OBT Node, then you have to keep looking. However, when it works, it seems to be pretty obvious, at least in my hands. One of the major values of using a program such as QL is to be able to use the barrel time output for the purpose of targeting OBT Nodes. In that event, the use of the software can certainly facilitate and expedite the reloading process. If you cannot hit a given OBT Node due to barrel length, bullet, or powder selection, the program is somewhat less useful, although having solid pressure/temperature predictions is never a complete waste of time, IMO. The good news is that reloading programs are not essential for developing solid loads. They can sometimes help, but you can reach the same endpoint regardless of whether you use a reloading program or not. So I try to take advantage of their use to facilitate load development when/if it appears that a given load will fall very close to a predicted OBT Node, but am not dependent on the software when the load clearly isn't going to be close to an OBT Node. Another benefit to having QuickLoad is that you make very good predictions as to what barrel length you need with a given powder and/or bullet weight to actually target a specific OBT Node. That is not necessarily always helpful with an existing setup, but can be very useful to help you choose barrel length, freebore length, etc., when deciding on specs for a new barrel.

Ned

All very solids points. Thank you. I wish I had known about Optimized Brrel Timing years ago. Would have saved lots of time and components.

Do you think that tuners reduce the need to focus on OBT nodes? Aren't they adjusting the barrel harmonics to time with the bullet exit?

 

[Ned Ludd]

Ned

All very solids points. Thank you. I wish I had known about Optimized Brrel Timing years ago. Would have saved lots of time and components.

Do you think that tuners reduce the need to focus on OBT nodes? Aren't they adjusting the barrel harmonics to time with the bullet exit?

Tuners do not directly regulate internal combustion, they regulate barrel harmonics. For that reason, my opinion is that one should always work up a load as best as can possibly be done using traditional methods (i.e. charge weight, seating depth) before setting the tuner. Although setting a tuner properly can tighten short range groups up with a sub-optimal load, it cannot miraculously improve or somehow mask the sub-optimal combustion characteristics of a sub-optimal load (i.e. poor ES/SD), which will eventually show up on the target, especially at longer range and/or during longer strings of fire.