How to reduce SD & ES

[amlevin]

I apparently have a bunch of "rebellious" loads. They don't know what's supposed to happen. I increased the neck tension to a full .003" and "bingo". ES, SD, went down and group sizes shrunk as well.

Everyone told me to use less neck tension but when I did, every "number" went up except speed.

Powder, load density, neck tension, jump, temperature, wife's mood, your mood, the mood of the guy next to you at the range, whether or not your kids are bugging you for money, ---------- I'm convinced that they all cause the ES/SD numbers to vary. Sometimes I think I need an "Exorcist" more than I need a "Loading Manual".

 

[amlevin]

But finding a bullet that a barrel really loves is often the better long term solution because this gives more margin for variation in factors over which the shooter has less control: temperature, air density, barrel conditions, etc.

And once you find that bullet, the manufacturer suddenly "has a shortage". The bullets both my rifle and I like best haven't been available for over a year now.

 

[alton9]

Savagedasher,
Why would you reduce the load to 35 gr? As I posted earlier, I'm afraid that would put me pretty close to .223 velocities. Am I missing something?

WyleWD,
I thought it was a pretty good load because I get consistent 1/2 MOA groups out to 300 yds. I get taller groups at 600 & 900, something on the order of 1 MOA at 600 & 2 MOA tall at 900 but they're conspicuously narrow ( 3/4 MOA horizontal spread). Of course this is in decent wind & mirage conditions. So I got to thinking, if I can hold 3/4 MOA horizontal at these distances, why can I not hold the vertical that close? So I got a chronograph & here I am .
I'm hoping to get pointed in the right direction so I can make an improvement without burning up a couple hundred bucks worth of hard to come by components. As I posted in a thread a couple of months ago, my goal is to make a clean kill on a coyote at 1000 (or more) yards. I think I must have less vertical than I'm getting now to accomplish that. Maybe this rifle is not the one to reach out that far with, but it's my current favorite.
Thanks again to all, alton9

 

[Michael Courtney]

But finding a bullet that a barrel really loves is often the better long term solution because this gives more margin for variation in factors over which the shooter has less control: temperature, air density, barrel conditions, etc.

And once you find that bullet, the manufacturer suddenly "has a shortage". The bullets both my rifle and I like best haven't been available for over a year now.

We've got it even worse. The highest BC bullet that one .223 loved was the 62 grain Berger flatbase varmint bullet, now discontinued. When my son shoots the last of them in a match this March, they are gone for good and we're back to the drawing board on that rifle. It also loves the 40 grain VMAX, but that is not going to play in F Class. It might be time to switch to a higher twist barrel if the children maintain their interest in F Class.

I apparently have a bunch of "rebellious" loads. They don't know what's supposed to happen. I increased the neck tension to a full .003" and "bingo". ES, SD, went down and group sizes shrunk as well.

Everyone told me to use less neck tension but when I did, every "number" went up except speed.

Powder, load density, neck tension, jump, temperature, wife's mood, your mood, the mood of the guy next to you at the range, whether or not your kids are bugging you for money, ---------- I'm convinced that they all cause the ES/SD numbers to vary. Sometimes I think I need an "Exorcist" more than I need a "Loading Manual".

You had me literally laughing out loud!

For every example supporting a lot of theories in ballistics, there is an equal and opposite counter example. I can usually repeat a sweet spot accuracy wise or SD wise, but all the variables need to be held constant to do it reliably.

Except for the 40 grain vmax in that .223. We loaded up a few hundred of these for a project Appleseed in mixed and matched brass, powders, primers, etc. Broke every rule of consistency. Didn't end up going to that Appleseed and the children have been shooting dime groups at 100 yards every trip to the range. Freaky.

 

[expiper]

#9,,,,you have gotton some good advice from some bona-fide competitors telling you the first thing you learn when shooting ,,,,if you have vertical then use more powder,,,,when you get too hot you will be poping shots once in a while,,,that tells the top and bottom end of your load window,,,the powder will not burn right if there is not enuff pressure in the case (ooo I know all about Lead bullet loads) ,,,and you are wanting to "kill" vermin at extreme range,,,,MORE POWDER,,,Roger
PS,,,try Sierra 80 gr SMK's ,,,they will tell what the gun will do,,,

 

[WyleWD]

wyleWD,
I thought it was a pretty good load because I get consistent 1/2 MOA groups out to 300 yds. I get taller groups at 600 & 900, something on the order of 1 MOA at 600 & 2 MOA tall at 900 but they're conspicuously narrow ( 3/4 MOA horizontal spread). Of course this is in decent wind & mirage conditions.

Thanks alton9, makes perfect sense now. Appreciate your response.... I agree with expiper.... more powder. And or maybe a change of primers. ??? WD

 

[BigDMT]

Sure the SD and ES can be reduced with a load, but the main problem is the lack of sufficient BC using the 75gr A-Max. It will still give you trouble at 1K, especially on small targets like coyotes.

With a BC of only .435, The 75gr A-Max is lacking for extended long range shooting. Even if he is getting 3200-3300 fps, it's just not going to be enough for 1K shooting.

As the bullet slows it becomes more susceptible to atmospheric conditions, especially wind. And cross winds are not always the worry. A good head wind on a slow bullet as it dives down to the target can make accuracy very inconsistent. It also starts to wobble more as it slows causing more accuracy problems by allowing air to effect it more easily. Just the same as spinning a child's toy top on a table, it wobbles more as it slows.

I have the same problems with my 204 Ruger. My 204 will shoot 39gr Sierra BKs under 1/4 MOA at 200 yards and easily stay under 1/2 MOA at 300. But once you get it out past 600-700 yards, the BC of the bullet causes it to lose a lot of steam and it becomes unpredictable, even though it leaves the muzzle at over 4000 fps. I proved this to myself by taking it down to a 1K BR match the other year. We played with it and couldn't get a bullet to land on target. The spotter in the pits couldn't even tell where they were hitting in the dirt because the spread was so big. The bullet was tumbling. Out to 800 it did ok, but those last couple hundred yards were just too much for that bullet.

My 358 Norma Mag is the same way. The best BC bullet I can get for it in the 225-250gr weight range is .446. The bullets I use are 225gr and have a BC of .430. They leave the muzzle at 3030 fps and will shoot 5 shots into 1.5" at 300 yards. ES is about 12 fps on my load, but once you shoot that rifle past 700 yards, it becomes very inaccurate. I can keep it MOA at 700, but 800-900-1000....I would never shoot at an animal because the bullet has lost so much velocity it does not have consistent and dependable accuracy.

I remember talking to all the 1K BR fellas I shot with about building a 22 Dasher or some other sort of large 22 for 1K competition. EVERY one of them told me NOT to do it. I didn't question them much about it, just knew that they probably tried such things themselves at some point and it didn't work very good.

Basically what I'm saying is that like it or not, the truth is that you might have to step up to a 90+gr VLD style bullet or build a larger bore rifle to do the type of shooting you want. Components may be scarce, but it is what it is. Your not gonna make a race horse out of a donkey no matter how hard you try

 

[Michael Courtney]

Savagedasher,
Why would you reduce the load to 35 gr? As I posted earlier, I'm afraid that would put me pretty close to .223 velocities. Am I missing something?

While I can appreciate the desire to "fix" the problem without burning hundreds of dollars in components, sometimes more data for an improved diagnosis is needed and thoughts of going directly to a fix are overly optimistic.

You've already got accuracy and velocity data for 37 grains. Shooting one five shot group with 35.0, 35.5, 36.0, and 36.5 grains and recording mean, SD, and ES along with group size and relative location at 300 yards will tell you a lot with minimal risks of creating over pressure conditions. In contrast, going above book max in hopes of a quick fix is ill-advised. I think you said you were using full sized not previously fired Win brass, so you've had minimal opportunities to see loose primer pockets or some other pressure signs in the brass. CCI primers don't tend to flatten until pressures are really high.

You are mostly inferring safe pressures from low velocity readings on an unproven inexpensive hobbyist chronograph. Well, you can't get high velocity without high pressure, but you can sure get high pressure without high velocity.

I would not say to never, ever, ever go above book maximums when reloading. But doing so requires the exercise of a lot of care and double checking. We do it from time to time in a controlled laboratory environment. When considering going above book maximum here are some things we carefully consider first:

1. What is the actual powder capacity of the chamber and brass under consideration. We measure the weight in water of ten cases that have been fired several times in the chamber.

2. How much extra case capacity is there due to OAL above that with which the data was developed?

3. Are there any signs of overpressure? Loose primer pockets after multiple firings? High pressure readings on a pressure sensor? Unreasonably high velocities for the cartridge, bullet, and powder?

4. Double check the reloading scale. Triple check the reloading scale.

5. Is the current book maximum the result of lawyering? Do earlier editions of the reloading manual show higher maximum loads?

6. Are there lot to lot variations of the powder that suggest we may be working with a slow lot where more powder is needed to achieve velocities safely achieved with this powder in the past?

7. Might the powder have absorbed some humidity and be reading a couple percent high in weight for the same amount of actual nitrocellulose?

We also remotely triggered above book loads until we could establish that pressures were safe.

 

[alton9]

Michael,
I have no reason to think that my load is "hot". Currently I'm shooting a new batch of brass, but I have used this load in a previous batch many, many loadings. There were no loose primer pockets, only the occasional split neck, and this brass had been used with 3 different rifles over the years. I only replaced it because it had an obscene number of loadings.
Yes, I have data for the 37 gr. load, and I'm not satisfied with that velocity. My hobbyist chronograph velocities are supported by the required come-ups at all distances. I could live with this velocity, if I didn't get (what I think is) excessive vertical, but I absolutely don't want to intentionally reduce it unless there is no other option.
I'd like to mention, I've found that the .22-250 with heavy bullets is sort of like a wildcat, in that there is very little published data out there. I do suspect the current book max IS a result of lawyering, but I only have data in one manual, so what could I compare it to?
Thank you for your input, I hope I don't seem argumentative or stubborn, I just want to fully understand everyone's viewpoint.
Alton9

 

[Michael Courtney]

Michael,
I have no reason to think that my load is "hot". Currently I'm shooting a new batch of brass, but I have used this load in a previous batch many, many loadings. There were no loose primer pockets, only the occasional split neck, and this brass had been used with 3 different rifles over the years. I only replaced it because it had an obscene number of loadings.
Yes, I have data for the 37 gr. load, and I'm not satisfied with that velocity. My hobbyist chronograph velocities are supported by the required come-ups at all distances. I could live with this velocity, if I didn't get (what I think is) excessive vertical, but I absolutely don't want to intentionally reduce it unless there is no other option.
I'd like to mention, I've found that the .22-250 with heavy bullets is sort of like a wildcat, in that there is very little published data out there. I do suspect the current book max IS a result of lawyering, but I only have data in one manual, so what could I compare it to?
Thank you for your input, I hope I don't seem argumentative or stubborn, I just want to fully understand everyone's viewpoint.
Alton9

For me, velocity can only be verified with an independent velocity measurement.

Inferring velocity or BC from elevation adjustments or drops is unreliable because of the possible confounding factors, as well as the tendency toward confirmation bias.

Suspecting the book max is a result of lawyering is different from confirming it. When I find older published data that was based on pressure testing, but the newer published info is systematically lower, then it's lawyering.

I've checked multiple, reliable published sources, and 37 grains of H4350 is the highest anywhere for a 75 grain bullet in 22-250. Other sources have 36.0 and 36.5 grains as the listed max. Velocities vary, but 3100-3200 fps is consistent with a max load from normal length barrels. The expectation that pressure is safe if you keep the velocity under 3300 fps is unrealistic. If checking other sources showed 37.0 grains were the lowest max listed and some sources went up to 38 or 39 grains, you'd be better informed and carefully moving up in small increments would be better supported.

Another approach is to carefully measure the case capacity as I described above. If the capacity of you cases is much larger than the default value in QL, then one could run the numbers and have more complete information regarding the idea that maybe more powder is safe due to your chamber dimensions and brass.

 

[alton9]

Michael,
Where did you find multiple, reliable published sources for load data with the 75 grain bullets in .22-250? The Hornady manual is the only data I've found.....
Thanks, alton9

 

[savagedasher]

Hi Fellows,
I got a Magnetospeed for Christmas, now I see my SD is 23 and my ES is 66 on what I used to think was a good load... Where do you start to try to lower these numbers? I'm already weighing every charge, flash hole deburring, primer pocket uniforming, etc. Do I change primers? Powder charge? Powder? Any help is greatly appreciated.
Alton9

Guy you ask how to lower SD and ES. I checked Hogdon powder they said 36Gr was max for a 70 gr bullet .Hornady said the same for a 70 GR bullet. OL says with a case that holds 43.49 of H20 your getting 68843 Psi with 37.2 gr of 4350 your 109.9% full at 2.350. the case is rated for 65000 PSI. From what I see you intrest is not SD and ES . Larry

 

[Steve Blair]

Hi Fellows,
I got a Magnetospeed for Christmas, now I see my SD is 23 and my ES is 66 on what I used to think was a good load... Where do you start to try to lower these numbers? I'm already weighing every charge, flash hole deburring, primer pocket uniforming, etc. Do I change primers? Powder charge? Powder? Any help is greatly appreciated.
Alton9

Guy you ask how to lower SD and ES. I checked Hogdon powder they said 36Gr was max for a 70 gr bullet .Hornady said the same for a 70 GR bullet. OL says with a case that holds 43.49 of H20 your getting 68843 Psi with 37.2 gr of 4350 your 109.9% full at 2.350. the case is rated for 65000 PSI. From what I see you intrest is not SD and ES . Larry

[br]
That's a lot of assumptions, old son. Attached is a QL printout using actual load development data from my Savage .22-250. Ambient temp was ~80°F when fired. My end load, which I'll still withhold so as not to cause anyone to hide under the bed, was much higher than the 37.0 load listed here. After 11 firings, Winchester brass was still serviceable. The OAL listed here was a .021" jump in an 8" twist McGowen pre-fit and headspaced to .002" over min. I did not request a special reamer as the barrel was in their inventory. [br]
As previously noted in this thread, lot-to-lot variation in all components highly recommends caution during the load development process. That said, reloading manual values have very little to do with any field or match load that I've used in a very long time. True, you must start somewhere and they serve as a good reference for that purpose. But what do you do when you hit their maximum load and it is obviously well under full pressure? Stop? Why? [br]
I shoot a 6BR load with Berger 105 Hybrids in competition that is well over Hodgdon's recommended max. The Lapua brass was just fired for the 25th time in a 3X600 yard match 26 January where it won. The load has never shown pressure signs, even in 95° temps. It is a very accurate low ES load. How do you reconcile that with your slavish adherence to data derived in a different rifle, different powder lot, etc.? [br]
I am absolutely not counseling anyone to behave recklessly when developing loads. High pressures are involved and can pose a safety hazard if prudent procedures are not followed. Following those procedures does not mean shutting off your brain. It is actually possible to develop a full pressure load that exceeds reloading manual figures that is safe, reliable and accurate. Pretending otherwise is silly. [br]
Some years ago, I participated in an accident investigation for a firearms manufacturer for whom I was working. We contracted H.P. White Labs for the investigation. I have seen and experienced first hand what can happen when ammunition exceeds a firearm's ability to contain pressure. Just for the record, the accident was caused by military ammunition produced in Lake City Arsenal.

 

[BradY]

Basic observations.

Each rifle/chamber/barrel is different. One rifle can shoot 37gr safely the next may only get to 36. If the chamber is long throated that could be saving you pressure wise. And if its a barrel that has seen a fair bit of work or is rifled to a little larger than normal then this could be saving you pressure wise. If the OP has pressure problems, they will start to experience sticky bolt lift, cratered/flat or starting to pierce primers and primer pockets will grow loose quite quickly- especially with a 22/250.

The 22-250 and 75 amax will make it to 1000yds if thats what your trying to do. Will it be optimal for the job? Probably not.

If its a hunting gun, keep it for sub 600yd shots. Work on getting it to shoot small at 100yds. An OCW test is a good way to identify what powder charge works well then you can tune your groups with seating depth. If its a target gun theres a few things you can try- the OCW test and seating depth test as described, try different powder and primers to get the velocity you want with the best SD and ES, then have a tuner or tuner brake installed to be able to tune your group size/shape, or upgrade to a caliber on the same boltface that will shoot 1000yds more accurately with less drift. A 6.5x47L with 123-140gr bullets would work well.

 

[savagedasher]

Steve. I'm not here to argue over what someone does loading. But several sources stated with
H 4350 and 75 gr a max the most accurate and the lowest SD was with wolf mag primers and 45 gr of 4350. Brux barrels are normally tighter then any other. Mc Gowen is normally on the loose side. If the man want help to lower his ES and SD I was trying to help. If speed is his reason I don't want to give that information to anybody. I have a good friend that was blowing primers with a mild load of varget. A full 1 1/2gr under what he was shooting last year. It wasn't because his load was bad. He had a bad carbon ring. The advice I gave was just (my) opinion. The only load I found that was close to his was with molly bullets. My 60 years of reloading Is not needed. Larry

 

[alton9]

Savage dasher,
Thanks for the reply. I assure you my interest is in reducing SD & ES. I can also assure you I'm not anywhere near 109.9% full. As to the charge weight I've been using, it's 37 gr of H-4350. My 8th edition Hornady manual shows 37.2 gr of this powder as max for the 75 gr Amax. This is the ONLY source of data I've found for this bullet in this cartridge. With all due respect Sir, I haven't exceeded the book max yet, and I may not. I simply wanted to know what things more experienced shooters changed to attempt a positive change in these numbers. Although I value tremendously the knowledge base provided by the members here, ultimately , I'll have to make up my own mind on what to try. Accordingly, if I do something stupid or ill advised, it's on me.
Thanks again for your opinion & reply, alton9

I just saw your latest post & would like to add, speed is not why I'm seeking advice, but given that I'm shooting slower than I'd hoped I'd rather not give up any speed if not absolutely necessary.
You might want to edit your post, I'm pretty sure you didn't mean 45 gr
Thanks, alton9

 

[savagedasher]

Thanks35 GR LARRY

 

[amlevin]

I simply wanted to know what things more experienced shooters changed to attempt a positive change in these numbers.

Yesterday I went to the range and set up my Chronograph. Had 50 rounds, loaded in groups of 5 starting at the "Starting Load" and increasing by .3 gr until I reached the published max load.

All cases were prepped the same. Bullets all seated with the same "feel" indicating that neck tensions were uniform (as close as one can "feel" anyway).

Interesting data came from this session. Starting load had an ES of 20 and an SD of 8.8 fps. The ES dropped to 18, 12, 11, while the SD dropped to 7.8, 5.7, and 4.1 respectively.

These numbers then climbed again until I reached a "full case load" where the EX dropped to 12 and the SD to 5.

Case fill can cause the ES and SD numbers to rise and fall. When I graphed the 10 charges it looked like a "Tide Chart".

One thing for the "I only look at the paper (target) guys," funny thing was that the smallest groups came from the loads with the lowest SD (and Mean Absolute Deviation which my chrono also spits out).

Best group had a MAD of only 4 feet per second with a SD of 5.

Maybe those "numbers" do mean something

 

[alton9]

Amlevin,
Thanks. I used a ballistic program to calculate drop at 900
Yds with my load at 3100 fps and again at 3166 fps ( I have a 66 fps E/S). IIRC, the program showed a 1.1 MOA difference. If I can hold a 1 moa group, but my load can vary POI by 1.1 MOA, it seems to me that would translate to about a 2.1 MOA group. There's no way the numbers don't matter.
It's interesting that your E/S dropped as charge weights increased.....
Thanks again, alton9

 

[amlevin]

Amlevin,
Thanks. I used a ballistic program to calculate drop at 900
Yds with my load at 3100 fps and again at 3166 fps ( I have a 66 fps E/S). IIRC, the program showed a 1.1 MOA difference. If I can hold a 1 moa group, but my load can vary POI by 1.1 MOA, it seems to me that would translate to about a 2.1 MOA group. There's no way the numbers don't matter.
It's interesting that your E/S dropped as charge weights increased.....
Thanks again, alton9

If you check out Brian Litz's new external ballistics program on the Applied Ballistic's website you'll notice a neat little addition at the bottom of your calculated data. He has come up with a probability prediction.

As an example, for a load I was looking at, his "prediction" showed that if my wind call was within 1 mph and my SD was 5 the probability of hitting the target out at 1k was 91%. If the SD climbed, and wind calls were off by increasing amounts the probability of a hit went down. An SD of 15 and only another 3 mph wind call error reduced the probability of a hit to 5%.

May not matter to those who shoot at up to 300 yards but when you reach out to distances where the target is barely visible to the naked eye, those "numbers" are everything. That is unless your "discipline" allows misses to be ignored and only hits are scored :