Testing and estimating 223 loads for summer in winter + other questions

[Near miss]

Hello,

I am seeking the max powder charge to find out where the pressure signs start to show. Mostly to see how far off my charge is from unsafe. I also want to then compare the loads done in the summer to get a feeling of how many grains are needed to drop from winter loads to summer for future reference. I will make one load for all weather since that is maybe the strong side of N140 in addition to good accuracy.

My gun is MR223, it probably has 556 chamber.
I have already loaded 70gr VLD to 25.8gr of N140 and had very slight primer flattening in . I now loaded few 25.9, 26.1 and 26.2gr loads to see where it starts to show. Do you have any idea how far off I need to go? I doubt I will make ammo with more than 25.8 in it as it gets quite compressed beyond that and I want also to not weight the charges, just throw them.

I do not think that going higher than 26.2 is necessary for testing if I settle at 25.6 and some of the throws might stretch to 25.8? How much do you estimate I will have to drop the charge by for the 100F temperatures if at all?

I will not be shooting 70VLD much more, I am switching to scenars but this same issue still stands.

In short:
How pressure/charge aware should I be, considering variance from throwing and temperature?

 

[stello1001]

No one can tell you an amount where you reach pressure. You have to do your own testing in incremental values until you find it.

 

[roostercogburn98]

^^^^^^every gun is different. It’s up to you on how far you want to push it and see how close you can get. I’m good not running max plus charges and keeping everything like it’s supposed to be, including my fingers and face. Too many variables to tell exactly where each gun will start to show pressure signs though.

 

[Near miss]

No one can tell you an amount where you reach pressure. You have to do your own testing in incremental values until you find it.

I was thinking of doing warmed up test this weekend by putting them in a warm pocket but it is kind of stupid since I do not know the real temp anyways. To be sure it needs an insulated and heated box and even then there are other factors such as cold gun acting differently. I prefer to measure ambient and let the rounds settle to that in 20-30mins and shoot.

A IR temp meter is quite bad since I noticed it reflects quite a lot of temp so it is unreliable, I even tried painting the part I measure black but it still varied depending where the angle pointed.

 

[stello1001]

I was thinking of doing warmed up test this weekend by putting them in a warm pocket but it is kind of stupid since I do not know the real temp anyways. To be sure it needs an insulated and heated box and even then there are other factors such as cold gun acting differently. I prefer to measure ambient and let the rounds settle to that in 20-30mins and shoot.

A IR temp meter is quite bad since I noticed it reflects quite a lot of temp so it is unreliable, I even tried painting the part I measure black but it still varied depending where the angle pointed.

You are really overthinking this by a huge margin. You are way over your head.

First of all, do you even have any idea what pressure signs look like when they start to show? If not, I suggest you do a bit more research and get familiarized.

If you do know, then start loading up incrementally different charge weights. Maybe go up in .3 increments from an already known safe load. Stop when you first notice pressure signs. Then you have found the charge weight you are looking for.

 

[roostercogburn98]

My gun is MR223, it probably has 556 chamber.

Start here. Figure out what chamber your rifle has. Small example of why that’s important.

556 max pressure is 62k
223 max pressure is 55k

There is 7k worth of difference in those two chambers.

 

[Near miss]

^^^^^^every gun is different. It’s up to you on how far you want to push it and see how close you can get. I’m good not running max plus charges and keeping everything like it’s supposed to be, including my fingers and face. Too many variables to tell exactly where each gun will start to show pressure signs though.

By looking at Vihta's load data I cannot find 70VLD but they list Berger 73gr at 25.3 and 75gr at 25.5 at 2260 COL. So most likely the max for 70VLD would be between 25 and 26.

You are really overthinking this by a huge margin. You are way over your head.

First of all, do you even have any idea what pressure signs look like when they start to show? If not, I suggest you do a bit more research and get familiarized.

If you do know, then start loading up incrementally different charge weights. Maybe go up in .3 increments from an already known safe load. Stop when you first notice pressure signs. Then you have found the charge weight you are looking for.

I have started the charge tests from 23.4 grains. From there I jumped to 23.9gr and climbed steadily .15 grains at a time.
I know of pressure marks, have investigated my small share of weird range brass and also enjoyed Greg's article on it. But I am still a beginner so I want to go slow. I definitely feel I am overthinking this once again, but I'd really want to know ahead of time what is coming.

Start here. Figure out what chamber your rifle has. Small example of why that’s important.

556 max pressure is 62k
223 max pressure is 55k

There is 7k worth of difference in those two chambers.

I have understood all MR223s have 556 chamber. Of course they are quite similar to 223, mainly separated by throat length? Surely the brass is what gives in at those pressures, not the gun? But the same pressure is achieved earlier in a 223 chamber.

 

[Steel head]

Try 23 grains of WST
Should find some nice pressure with that.

What a dumb concept, OP, your looking at reloading all wrong!

 

[Near miss]

Try 23 grains of WST
Should find some nice pressure with that.

I will try pistol powders but mainly for subsonics just for amusement. Not sure how the gun would react to that much powder..

It seems HKs have some kind of nato-combatible chamber but I still have no original data. To my knowledge they label the barrels 223 because some countries in Europe do not allow civilians to own military chamberings / ammo.

 

[spife7980]

I will try pistol powders but mainly for subsonics just for amusement. Not sure how the gun would react to that much powder..

It seems HKs have some kind of nato-combatible chamber but I still have no original data. To my knowledge they label the barrels 223 because some countries in Europe do not allow civilians to own military chamberings / ammo.

That’s because it was a joke and you ignored the pertinent part of his comment.

Test upwards until you start to find signs and then back away

Understanding Pressure :: Primal Rights, Inc

Reading pressure is a required skill that all shooters must have. Whether you are shooting factory ammunition or your own handloads, you absolutely must be able to detect and interpret pressure signs on your fired brass.

www.primalrights.com

 

[roostercogburn98]

Surely the brass is what gives in at those pressures, not the gun?

So most likely

Two statements that show your cavalier attitude towards reloading. Stop, hit reset and get a real game plan

 

[Near miss]

That’s because it was a joke and you ignored the pertinent part of his comment.

Test upwards until you start to find signs and then back away

Understanding Pressure :: Primal Rights, Inc

Reading pressure is a required skill that all shooters must have. Whether you are shooting factory ammunition or your own handloads, you absolutely must be able to detect and interpret pressure signs on your fired brass.

www.primalrights.com

I know it was a joke, it was semi funny. As said I have been going up .15gr at a time.
What I would like to know is am I even getting close and how much I will likely need to back off when the temperature rises. Is it 1gr? .5? .3?
Not looking the absolute truth but just some guidance.

Put it another way, what charge would you recommend to start from in 50F or 100F if I see weak pressure signs (primer not flat but not totally in unfired roundness either) in some of the brass, start to appear at 25.8gr in 20F?

I would just want some baseline and not. This is because I try to find nodes that are also summer doable, not just for winter. I rather take the good mv with zero risk. But why go too low.

 

[spife7980]

I know it was a joke, it was semi funny. As said I have been going up .15gr at a time.
What I would like to know is am I even getting close and how much I will likely need to back off when the temperature rises. Is it 1gr? .5? .3?
Not looking the absolute truth but just some guidance.

Put it another way, what charge would you recommend to start from in 50F or 100F if I see weak pressure signs (primer not flat but not totally in unfired roundness either) in some of the brass, start to appear at 25.8gr in 20F?

I would just want some baseline and not. This is because I try to find nodes that are also summer doable, not just for winter. I rather take the good mv with zero risk. But why go too low.

No idea, I dont use vv powders and dont know of many who do over here but the manufactures put out their guidelines for a reason.

Rifle reloading data | Handloading | Rifle calibers | Centerfire Rifle bullets | Reload your own ammo - Vihtavuori

Vihtavuori offers rifle reloading data for numerous calibers and bullets for match and hunting purposes. Never exceed maximum loads.

www.vihtavuori.com

Follow their advice until you figure out what the hell youre doing because it sounds like youre trying to blow your face off with some fished up specific internet advice thats is going to inevitably be very wrong.

 

[Near miss]

No idea, I dont use vv powders and dont know of many who do over here but the manufactures put out their guidelines for a reason.

Rifle reloading data | Handloading | Rifle calibers | Centerfire Rifle bullets | Reload your own ammo - Vihtavuori

Vihtavuori offers rifle reloading data for numerous calibers and bullets for match and hunting purposes. Never exceed maximum loads.

www.vihtavuori.com

Follow their advice until you figure out what the hell youre doing because it sounds like youre trying to blow your face off with some fished up specific internet advice thats is going to inevitably be very wrong.

Thanks, I was guessing that there is no certain data. Do you have any data of other single base powders, or perhaps double base? Not going to apply them to my powders but I'd really like to know powders and how they react better, also overall.

I am going to start load development for 77gr scenar soon and I am weighing using N140 against N540. Would I get higher average velocity over cold to hot with N140, since I cannot load N540 that high since it is temperature sensitive?

 

[Near miss]

I fix the title to consider temps, it is a bit misleading and may have contributed to how my questions were received. I am not looking max charges, just want to know if my loads developed in winter will blow my face off at summer or not.

It seems it is quite futile to make development near listed maximums in the winter because of this.

 

[spife7980]

Thanks, I was guessing that there is no certain data. Do you have any data of other single base powders, or perhaps double base? Not going to apply them to my powders but I'd really like to know powders and how they react better, also overall.

I am going to start load development for 77gr scenar soon and I am weighing using N140 against N540. Would I get higher average velocity over cold to hot with N140, since I cannot load N540 that high since it is temperature sensitive?

There’s charts out there but it’s sort of not helpful just because of all the variables that can effect it

 

[FLIGHT762]

There’s charts out there but it’s sort of not helpful just because of all the variables that can effect it
View attachment 7805726

You have to be careful when using these charts. This chart shows AR Comp being in the same speed category as Reloader 15 and Varget.

I use a lot of AR Comp and there's no fucking way it's that slow. It's nearer IMR 3031 / Benchmark /8208.

 

[spife7980]

You have to be careful when using these charts. This chart shows AR Comp being in the same speed category as Reloader 15 and Varget.

I use a lot of AR Comp and there's no fucking way it's that slow. It's nearer IMR 3031 / Benchmark /8208.

Yep.

This is why everyone is telling you to do your own careful testing @Near miss

Start low and work up.
If youre worried about results months from now just dont load more ammo than you can shoot in that time period and test again in a bit.

 

[semperfireloading]

older folks here can tell you, load books from even the early 80's are so much higher charge weights than today, its not even comparable. I think the term "unsafe" is massively exaggerated, and what is meant is more like "wear and tear" increases. Brass life decreases a lot. But all that aside, going super high pressure is practically useless unless to experiment, because it won't be accurate with a smashed ogive bullet and huge compression load.

I agree with the other poster. Going by some chart is a big mistake. Never do that. AR Comp is a great example from that matrix. so is so many others.

In reality, AR Comp's load data for most 223/556 applications will be very near "Benchmark" and or slight LESS charge, as AR Comp is slightly faster. I would probably say its in between N133 and Benchmark, but closer to Benchmark.

N135 is also 3 rows DOWN than benchmark. I can tell you right now. N135 is nearly identical to benchmark in load data. N135 is also faster than TAC for sure. My tests show Benchmark, H4895 and N135 are nearly identical in 77 grain bullets in velocity with same charge weights.

77 grain max with Benchmark is like 22.8, as is N135 and H4895 right there. Never use a chart. Use manufacturing data. (for example)

The main difference between your result and manufacturer data is going to be the BRASS you use. If you use Starline 223, which weighs like 101 grains, it has very low case capacity, so pressure will be much higher same charge, as say Norma brass which weighs over 10% less at around 90-91 grains. Which will have giant case capacity.

I don't think going super hot with N140 is the right play with that bullet. I think the sweet spot for that bullet is near 25 grains of N140. Or RL15, or SW Prec Rifle or varget. If you are seeking super high velocity, N140 is a bad pick. You want Accurate 2520 or PP 2000 MR, or PP varmint, or TAC even would be better. Because you can shove a shitload more powder in because they are not medium bulky like N140.

good luck, I hope this helps you.

 

[Huskydriver]

Sounds like you and @rustyinbend went to the same reloading school

 

[semperfireloading]

oh also, in reloading, the main measurement to determine load data is "bullet length". For example, 50 grain Federal Frangible are about 1" long, just like near some 77 grain bullets. And guess what. The load data from the 77 grains is extremely close in the 50 grain bullet. Pressure is near the same at the same load in the 50 and 77 grain bullet.

So you don't need 70 grain load data, just measure how long it is, and then use comparable load data to something near that long.
Also, after looking at this thread again, its amazing we are all still alive, reloading is more dangerous that swimming with great white sharks. I didn't know loading barely over max can lead to bodily harm and is extremely dangerous. I been reloading for so long, and I never experienced that. But then again, the gun world is full of myths. Watch..some guy will load up 25 grains of titegroup and tell me I was wrong. I guess common sense is not common sense anymore, unless the manufacturer data tells me it is.

 

[Near miss]

Well yeah, the chart does not look like it is the answer to all powder questions. It is more useful for someone to get a grasp of how they bracket. Hodgon had a pretty good one.

I asked VV directly about temperature tables but they said sensitivity changes too radically with different components to make a comprehensive table. I hope they would even make an attempt at it.

I am using Sako brass, measured few and they seem to have 31gr of H2O capacity. I am not about to stay where I see pressure, just to know how far off I am now. I think 25.3gr is pretty good spot for this bullet.

The sako name has engraved my bolt in few places, good that I do not use mixed brass as it would look weird.

 

[MK20]

Hello,

I am seeking the max powder charge to find out where the pressure signs start to show. Mostly to see how far off my charge is from unsafe. I also want to then compare the loads done in the summer to get a feeling of how many grains are needed to drop from winter loads to summer for future reference. I will make one load for all weather since that is maybe the strong side of N140 in addition to good accuracy.

My gun is MR223, it probably has 556 chamber.
I have already loaded 70gr VLD to 25.8gr of N140 and had very slight primer flattening in . I now loaded few 25.9, 26.1 and 26.2gr loads to see where it starts to show. Do you have any idea how far off I need to go? I doubt I will make ammo with more than 25.8 in it as it gets quite compressed beyond that and I want also to not weight the charges, just throw them.

I do not think that going higher than 26.2 is necessary for testing if I settle at 25.6 and some of the throws might stretch to 25.8? How much do you estimate I will have to drop the charge by for the 100F temperatures if at all?

I will not be shooting 70VLD much more, I am switching to scenars but this same issue still stands.

In short:
How pressure/charge aware should I be, considering variance from throwing and temperature?

Damn, ok.

First, stop worrying about 223 vs 5.56. Is there some difference? Yes. Will that difference blow your gun up? Probably not. You are more likely to die in a car accident on your way to the range. It is a stupid debate for internet commandos who don't spend enough time in the real world jamming ammo into their guns.

One problem solved.

Now, about working up a summer load...

Load up some rounds in escalating powder charges. Put them in a cooler with a jar of really hot water which is seperated from touching the rounds by a towel. Throw a cheap analog meat thermometer in there from your local grocery store. Wait for the ambient temp to reach your max possible summer temp and let the rounds soak at that temp for a while, like 30 minutes.
Shoot them and see when pressure signs show. The last load to not develop pressure signs is your max summer load.

Gun temp doesn't matter. What matters is burn rate of the powder. Technically a cold barrel burns powder slower, but not significantly. If your barrel is an icicle, shoot it a bit and it magically warms up if you are still worried.

Mainly, stop overthinking it. HK has had a policy for a long time that any of their guns can have a bullet lodged in the barrel and the next will be able to shoot it out without blowing the gun up. IDK if they still do this, but they know how to make good guns. You won't blow it up unless you are especially stupid with something.

 

[Near miss]

Mainly, stop overthinking it. HK has had a policy for a long time that any of their guns can have a bullet lodged in the barrel and the next will be able to shoot it out without blowing the gun up. IDK if they still do this, but they know how to make good guns. You won't blow it up unless you are especially stupid with something.

Man sounds fun, I hope I will not have to try that.

I do have trust in my gun but I still want to load and test the same way I would for a chinese discount gun. Because complacency never gets me anything good.

Damn, ok.

First, stop worrying about 223 vs 5.56. Is there some difference? Yes. Will that difference blow your gun up? Probably not. You are more likely to die in a car accident on your way to the range. It is a stupid debate for internet commandos who don't spend enough time in the real world jamming ammo into their guns.

One problem solved.

Now, about working up a summer load...

Load up some rounds in escalating powder charges. Put them in a cooler with a jar of really hot water which is seperated from touching the rounds by a towel. Throw a cheap analog meat thermometer in there from your local grocery store. Wait for the ambient temp to reach your max possible summer temp and let the rounds soak at that temp for a while, like 30 minutes.
Shoot them and see when pressure signs show. The last load to not develop pressure signs is your max summer load.

Gun temp doesn't matter. What matters is burn rate of the powder. Technically a cold barrel burns powder slower, but not significantly. If your barrel is an icicle, shoot it a bit and it magically warms up if you are still worried.

Mainly, stop overthinking it. HK has had a policy for a long time that any of their guns can have a bullet lodged in the barrel and the next will be able to shoot it out without blowing the gun up. IDK if they still do this, but they know how to make good guns. You won't blow it up unless you are especially stupid with something.

I will do the temp test as said, there are still some variances and I need to do it so that all the rounds represent the ambient temp (I have read that the powder can take really long to rise, but it will provide me so much valuable data.

I think I will heat the rounds within 30-60mins to 120F and then wait until the ambient is around 100F. This way all the ammo is at least 100F hot.

I will do this next weekend or the next weekend after that, I will be camping at the gun range for the whole time so I can easily do that kind of testing without problems. I even do not have to dig my rounds out of snow. I will do the test with 77gr scenars which will be my go to as VLDs continue to have supply issues.

I have had experiences in cold where the rifle barrel clearly sucked powder energy enough to change gun cycling so I will be shooting the gun warm.

Who knows, if the N140 is not enough compressible, maybe I will use some good old mortar and pestle and make some finer powder out of it.

 

[Near miss]

It seems 26.2gr is a good final stop, I started getting small wipes. These cases were of my friends PD, he got them free for training as they were a bit hot and broke PD's bolts. So many of them have already terrible swipes on them from the factory load. The other case was lost in the snow from each charge but luckily I got one of each.

Now waiting for the next weekend. I will post my temp sensitivity findings in another post if I get my chrono back from loan before I go there as it might deliver some interesting data.

 

[semperfireloading]

BTW, I think you are joking when you say good old mortar and pestle and make fine powder of out it. DO NOT DO THAT. You will blow up your gun. you cannot "ground" down stick powder into finer dust, as it totally changes the properties of it, and VASTLY increases the burn rate. So basically, in simple terms, you will turn N140 into like Accurate #9 or faster. you will get probably (high)100,000 PSI + of pressure using say 27 grains, since you wanted to fit more in the case by making it finer. Never, ever, EVER do this. You might not get injured, but what will happen is it will SNAP your bolt in HALF, and grenade the magazine out the bottom into 100 pieces, then it will either crack or hugely bulge your upper reciever. The brass will come apart in the base, and you will have total case head separation. I already tried that, and 10 other very dangerous tests to learn about powder using a string from far. If you don't believe me, call the manufacturer they will say same thing.

Also, BTW, quality brass manufacturers, like LAPUA for example, test their brass to survive ~30% higher than max load. So you little swipe is basically just causing more wear and tear on your parts is all that is happening. call manufacturer, they will tell you this too. Lapua, that is.

 

[camocorvette]

Helpful for temp changes. But still nonetheless test and verify your own components and equipment.

 

[Near miss]

BTW, I think you are joking when you say good old mortar and pestle and make fine powder of out it. DO NOT DO THAT. You will blow up your gun. you cannot "ground" down stick powder into finer dust, as it totally changes the properties of it, and VASTLY increases the burn rate. So basically, in simple terms, you will turn N140 into like Accurate #9 or faster. you will get probably (high)100,000 PSI + of pressure using say 27 grains, since you wanted to fit more in the case by making it finer. Never, ever, EVER do this. You might not get injured, but what will happen is it will SNAP your bolt in HALF, and grenade the magazine out the bottom into 100 pieces, then it will either crack or hugely bulge your upper reciever. The brass will come apart in the base, and you will have total case head separation. I already tried that, and 10 other very dangerous tests to learn about powder using a string from far. If you don't believe me, call the manufacturer they will say same thing.

Also, BTW, quality brass manufacturers, like LAPUA for example, test their brass to survive ~30% higher than max load. So you little swipe is basically just causing more wear and tear on your parts is all that is happening. call manufacturer, they will tell you this too. Lapua, that is.

Hell no I am mortaring that, would be easier to just buy the WST to blow myself up.

I do think the cases should by default be mark free or at least show minimal sign of pressure. All good as long as the charge does not stress the lugs (sticky bolt). Which is not easily apparent in semis.

 

[semperfireloading]

Here is some final points,

1. Nobody on here, or in the world, can tell you what load you need to stop because its too high pressure. Impossible.
2. Load books are just a guidance point because brass capacity and atmospheric condition has largest influence and can swing velocity by as much as 100 FPS, with significantly different pressure. The load book is a highly controlled "exact" condition, which will vary with bullet, primer, brass, powder lots. This is basic to understand. Just because book says SMK max load is say X and 55k pressure, doesnt mean you load X and you get 55k pressure. I have no idea why so many people assume that. its totally absurd nonsense.
3. The military uses NATO rounds, which mark up the brass, and shoot, I don't know. BILLIONS of rounds over time? Somebody forgot to tell all the ammo manufacturers that supply these rounds, they should be "default, mark free". What? Where did you learn that nonsense.
4. You have a largely temp stable stick powder, and your load is not even close to NATO pressures. Yet, NATO loads are BALL Powders that are MASSIVELY temp Sensitive, and they just had a war in the DESERT For 2 DECADES. So lets see, 120 degree heat, higher pressure than your loads, and using temp insensitive BALL Powders.,...hmmm. Let me tell you, its not them that is worried. So why are you? you know something all these companies and governments don't know?
5. Marks on the brass are not meaningful measurement because every brass brand, and even THE SAME, has different thresholds for marks. I just shot some 2925 FPS 77 Grain, 20" barrel in AR15 last weekend. High pressure, obviously. Why did some brass get marks and a few didn't?
6. Primer flattening, same thing. Because again, different primer brands flatten differently, and even same brand flattens differently. your pics of the primers? Those primers? Those are WELL rounded, and that pressure is a JOKE. You ever even seen flattened primers?
7. Military weapons, that are shooting in 120+ degree heat, using hotter rounds than you, don't have "lug" issues or "sticky bolts". How many M16's you think just went to that 20 year long war? A million maybe?

 

[Near miss]

You are totally right. I am not, definitely not, an expert on this but have just read that one might wear out the lugs without much noticing anything. This could however be just complete fiction. In my mind, I just try to interpret any limits and stay under them.

I am just trying to estimate / ask around if I will have problems in the heat. After all, I am a beginner. I have no clue how much it will affect the load, hopefully I will after this weekend. I do not want to get ahead of myself or make too big assumptions, it might get costly in this hobby.

Even in 20s we shot some Sellier (LMT) and they had flat primers and marks. Actually it was so tough I could not resize the brass, every brass required body weight assist to resize. Even then they did not headspace correctly, they gave me sticky bolt when I tried them (just the brass alone) in the gun. I might bin them.

I guess with 140 the difference between winter and summer load is comparable to .3gr of powder, so almost nothing. I am doubting N140 is the right powder for 77s either.

I will do load development with N140 and 77s and maybe return wiser. Probably the added 7 grains help the powder burn better.

 

[chase723]

I know it was a joke, it was semi funny. As said I have been going up .15gr at a time.
What I would like to know is am I even getting close and how much I will likely need to back off when the temperature rises. Is it 1gr? .5? .3?
Not looking the absolute truth but just some guidance.

Put it another way, what charge would you recommend to start from in 50F or 100F if I see weak pressure signs (primer not flat but not totally in unfired roundness either) in some of the brass, start to appear at 25.8gr in 20F?

I would just want some baseline and not. This is because I try to find nodes that are also summer doable, not just for winter. I rather take the good mv with zero risk. But why go too low.

Either develop loads in the summer or develop your loads in the winter then heat some of them up (vac sealed and in warm/hot water) and shoot them and see what your pressure is. If you are using a temp stable powder, often you don’t have to change them. Also don’t load the node at absolute max.

Given that you’re new to reloading, load/shoot a couple pressure ladders and learn how your rifle demonstrates pressure. That way you know what you are looking at. The rifle is not going to just all of a sudden detonate and blow your face off. It almost always builds in a stepwise progression.

Flat primers don’t mean anything. Pay attention to your ejector marks, bolt lift, and if carbon is escaping around the primer. Obviously a case head separation or pierced primer is too hot. Lol

 

[Near miss]

Brass looked quite nice. I had some wipes near end. Gotta say, this looks surprising. I might be doing this with warmed ammo soon or the same test with more ammo but with fewer different charges. This raised more questions than answers..

The accuracy was ok not that it mattered at all in this test. My target was a mess when I got to testing and I decided to just focus on chronoing.
The N140 produced 1.5moa group with 6 different charges and the N540 all charges in the same target did 1.4moa group. But promising, yes.