I have been trying to get my es lower for my .338 edge, I have not been below 34. My brass prep includes doing the primer pockets, flash hole deburring, very precise powder weighing, sorted and weigh bullets,chamber and debur by hand, trimmed and squared cases, dry graphite before seating the bullet. Just wondering if someone has any tips to get it lowere thanks
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Lowering ES whats the secret?
- Thread starter wyosniper
- Start date
How are you measuring your powder?
L
edt: reason asking is if you are using a Chargemaster they sometimes throw heavy or light as much as .5g's. Stacking that up you could potentially have a 1g variance at a particular charge weight.
L
edt: reason asking is if you are using a Chargemaster they sometimes throw heavy or light as much as .5g's. Stacking that up you could potentially have a 1g variance at a particular charge weight.
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What kind of primers are you using? I know when I went from CCI primers to Wolf primers...yes...Wolf primers...my ES and SD numbers went down A LOT.
Have you tried different powder? Some powders will yield better results then others.
How are you measuring your bullet seating depth?
Have you tried different powder? Some powders will yield better results then others.
How are you measuring your bullet seating depth?
That's a tough one to answer because there doesn't seem to be any well defined method that always results in lower ES. Some combinations of components just don't seem to shoot all that consistently. Case in point, I did load dev for months on my .338LM with Hornady's 285gr BTHP and could never get them to shoot well at all. And years ago I had similar trouble shooting 300 SMKs, thinking that maybe the 1:10 twist wasn't stabilizing them. I briefly tried the same load range with 300 scenars and got similar results. Now flash forward to recently and after my 285gr debacle I gave 300 Scenars a try again with N570 and all of a sudden I'm getting excellent groups comparable to my tried and true 250 Scenar loads. So was it just the powder or have my reloading skills really improved over the years? Hard to say? On another note, during 6.5x47L load dev I was getting really good performance with 136gr Scenars with N550 and GM205M primers. But I suspected I could squeeze the groups tighter, so on a whim I switched out primers to CCI450 and was astonished how the groups just collapsed onto each other, going from just under 1MOA to about 1/4MOA.
The point of all this is that there's no rhyme or reason to it, from what I can tell. As long as you're making very consistent uniform ammo in your hand loading process, swapping out components is often the only thing left to try.
The point of all this is that there's no rhyme or reason to it, from what I can tell. As long as you're making very consistent uniform ammo in your hand loading process, swapping out components is often the only thing left to try.
I am using a balance beam scale to make sure my rcbs 750 electronic is set up right and go on using it checking every 15th with the balance beam. The primers I have been using are federal magnum, and I am gonna try some federal match magnums next. The poweder I use h1000, I shoot great groups at 100, but I look at my chrony and I wanna blow that thing up, its mind fucking me. I also use a bullet compartor and I have a redding competition seater. I seat off the oggive. Ya I guess I could try some different componets, but it could be my handloads I suppose, I know I am know where close to being perfect on it.
Given my own experience with em that may be some of your problem. When you weigh every 15th are they ever off? I double weigh every charge throwing with a chargemaster and confirm with a Sartorius. I calibrate both of them with the same weights. The Chargemaster will be off a little almost every throw and alot every 4th or 5th. You could try to throw short with your chargemaster and use a trickler to finish with the beam. If nothing else it's a cheap test.
L
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so far, trying different powder and/or more consistent neck tension have yielded better spreads for me.
What instrument are you using for your velocity measurements? Remember that your chronograph has inherent errors. Unless you use some highly sophisticated radar chronometer, you are looking at a base error of about 12 FPS +/- at the best. I'd suggest doing some drop tests at long ranges to verify your chronograph readings and variations thereof. High quality bullets have their ballistic coefficients verified over long strings with expensive equipment. Try the drop tests before you berate your methods in the loading room. JMHO
I used to load the same way - pretty fast. But even though the RCBS 750 is one of the better electronic scales out there, it's nowhere near as consistent as a properly setup beam scale. Faster? Hell yes, but not consistent. Mine has a habit of drifting pretty frequently; in fact every electronic scale I've used (short of the GD503) has had that issue, so you can't rely solely on it unless you're just loading plinking ammo. But beam scales are pretty slow to work with, so my setup has evolved over time into a sort of hybrid situation.
I start with an old plastic powder can that I've cut in half that I pour the powder into. From there I use the Lee powder scoops to get a volume of powder into the pan on an RCBS750. If you pick the right scoop and flatten the top with a business card, you can get really consistent pours and it's fast. This step could be replaced by a good powder thrower instead but I stick with the scoops for now. The 750 is only used to get a quick read on the powder and it's intentionally loaded just under what the target weight is. Next, this powder goes into an RCBS 1010 scale that I've verified is zeroed properly. As the beam scale begins its settling process, I scoop up the next batch of powder and throw it in the 750. Then back to the beam scale, looking where it's settled - generally it will be within 0.5 grain of the target weight, so now I trickle up. I used to use an Omega Power Trickler, but I found it was faster for me to just grab a tiny pinch of powder and drop a couple kernels at a time until it hits the right weight. I've further refined this technique by upgrading to an Omega Auto Trickler, which has a light sensitive switch that can be setup to turn off the trickler when the target weight is achieved.* From here, I activate the auto trickler and it gets the last bit of powder in the pan then shuts off. Sometimes, depending on the powder type, I just have the auto trickler tricking air and drop the kernels in by hand, using the sensor only to determine that I've hit the proper weight (big kernels like N570 is perfect for this). From there the rest is easy - charge the case with the powder and then take an extra second of care when seating the bullets, making sure to use consistent force and be meticulous about COAL based on ogive.
I've been using this process now for about a year on 6.5x47L to .338LM with great results. It's not as fast as using a powder thrower and weighing every five or ten charges, but it's a hell of a lot more consistent. And compared to when I used a DPSIII, it's not that much slower, but again far more consistent.
Hmm, maybe I should do a video showing this process?
*there is a learning curve to using the Auto Trickler as it can be setup so that it unintentionally dumps too many kernels into the tray before the beam hits the target, causing a slight over weigh.
I start with an old plastic powder can that I've cut in half that I pour the powder into. From there I use the Lee powder scoops to get a volume of powder into the pan on an RCBS750. If you pick the right scoop and flatten the top with a business card, you can get really consistent pours and it's fast. This step could be replaced by a good powder thrower instead but I stick with the scoops for now. The 750 is only used to get a quick read on the powder and it's intentionally loaded just under what the target weight is. Next, this powder goes into an RCBS 1010 scale that I've verified is zeroed properly. As the beam scale begins its settling process, I scoop up the next batch of powder and throw it in the 750. Then back to the beam scale, looking where it's settled - generally it will be within 0.5 grain of the target weight, so now I trickle up. I used to use an Omega Power Trickler, but I found it was faster for me to just grab a tiny pinch of powder and drop a couple kernels at a time until it hits the right weight. I've further refined this technique by upgrading to an Omega Auto Trickler, which has a light sensitive switch that can be setup to turn off the trickler when the target weight is achieved.* From here, I activate the auto trickler and it gets the last bit of powder in the pan then shuts off. Sometimes, depending on the powder type, I just have the auto trickler tricking air and drop the kernels in by hand, using the sensor only to determine that I've hit the proper weight (big kernels like N570 is perfect for this). From there the rest is easy - charge the case with the powder and then take an extra second of care when seating the bullets, making sure to use consistent force and be meticulous about COAL based on ogive.
I've been using this process now for about a year on 6.5x47L to .338LM with great results. It's not as fast as using a powder thrower and weighing every five or ten charges, but it's a hell of a lot more consistent. And compared to when I used a DPSIII, it's not that much slower, but again far more consistent.
Hmm, maybe I should do a video showing this process?
*there is a learning curve to using the Auto Trickler as it can be setup so that it unintentionally dumps too many kernels into the tray before the beam hits the target, causing a slight over weigh.
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Plenty of good suggestions regarding powder mentioned above but don't overlook the effect of neck tension. Inconsistent neck tension will produce varying velocities. To achieve low ES numbers you will need to carefully sort your brass and most likely neck turn and use bushing dies without the expander.
Agreed, consistent neck tension is important too. The Redding S type dies (FL with neck bushing) are great for consistent neck tension without getting "benchrest OCD 'n stuff." Measure the neck OD on 10 loaded cartridges, average the numbers and then get a bushing that is 0.002 smaller. For example, with my 6.5x47L I get a 0.290" OD so I use a 0.288 bushing. And if you have to pull bullets for any reason, take the pin out of the die and re-run it through the bushing to reset the neck tension.
In my understanding, and I got this from several GOOD benchrest shooters, the bearing length of the bullet is more important than the weight of the bullet. I guess you could do both, but that would probably end up being a very small group of bullets. I measure the bearing length with a combination of the Sinclair Bullet Sorting Stand SINCLAIR BULLET SORTING STAND | Sinclair Intl and bullet comparators from David Tubb BSC insert .224 cal - BSC by Superior Shooting Systems . One of the two pieces in this set attaches to the stem of the dial indicator. In this way, you can measure the actual bearing length from the boattail to the Ogive.
Some other ideas which I use but have no proof they improve groups is to skim the necks (or you can actually turn them) which is supposed to even out the way that the case holds the bullet. Another idea is to anneal every other firing (I am expecting my Giraud in two weeks) New Page 1 . I trim meplats and then repoint my bullets Precision Reloading Equipment I coat my bullets with Boron Nitride from David Tubb Boron Nitride Coating Bullets - David Tubb
Another question is whether you can actually trust the ES measurements you are getting. I had an inexpensive Chronograph (~$150) and the eratic numbers I was getting were driving me nuts. I finally bit the bullet (pardon the pun) and got the industry standard Oehler 35P Oehler Research, Inc.--Model 35 Proof Chronograph I sort my brass in 0.1gn lots to indirectly control the volume of the case. Some claim that it is necessary to directly measure the volume using water. It is important to use cases with equal volume because that affects the amount of pressure generated which directly affects bullet velocity. Then a BIG part of lowering your ES is your load development and seating depth. I start with .5gn steps, measured to a single kernel of Varget with a Sartorius Magnetic Force Restoration scale Sartorius GD503-NTEP Class II legal for trade Carat Scale (which with the help of this website, I have modified to read in grains-- it is accurate to .005gn) and shoot 10 rounds at each step. Once I finish that, I vary the seating depth (make sure you do not jam the bullet in the lands if your load is anywhere near max or you could end up with a KaBoom!) Then I go back and fine tune the charge by varying the amount of powder in .1gn steps centered on the number I determined on the first coarse step. I am not sure which should be done first, determine load or seating depth, I can see advantages of each and it seems to be an iterative process since each affects the other one.
Then there is concentricity. Many question the value of adjusting this; however, it IS one thing you can control and I have CDO, which is the same as OCD, but the letters are in alphabetical order, as they should be. There are several tools out there to measure concentricity, I own three of them, but the one I like best is the Hornady model since it is the only one I have found that has a built in way to correct small concentricity problems. Of course, having a good press and good loading dies is the way you start having good concentricity. That's a data dump of everything I know about reducing ES. So far my best for 10 is an ES of 13 with an SD of 6, but I will not be happy with them until I get the ES in single digits.
Warning: This is not a cheap hobby as you may already be aware. The equipment I mentioned above comes to roughly $3K+, and that doesn't begin to include your press, dies, ammo components, rifle, optics, other reloading related measurement devices, other brass prep tools, shooting accessories, or gunsmithing services. Maybe it would be less expensive if I just took up drugs (probably less addicting too.)
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+1 on the chrono. My cheapo chrono was giving me 100 fps es on bad days and 25-30 on good days, despite shooting extremely tight groups (by my standards). I then tried my buddies magneto speed v2 and competition electronics chrono, and I immediately got single digit to low teen es on both of them. I ended up getting a magneto speed v2 from mile high and its definitely 10x more accurate than what I was using.
Also optimal barrel timing is something you should look at. Whenever you hit a solid node es and sd will tighten up a good bit.
I also dont agree with the chargemaster comments. If you are looking for es and sd of 5 then maybe the chargemaster isnt for you, but it throws very consistently for me. Plus when you are throwing something chunky like rl33, where each kernel weighs around .08 gr, how close do you expect to get even with a beam scale without sorting the kernels by weight?
Also optimal barrel timing is something you should look at. Whenever you hit a solid node es and sd will tighten up a good bit.
I also dont agree with the chargemaster comments. If you are looking for es and sd of 5 then maybe the chargemaster isnt for you, but it throws very consistently for me. Plus when you are throwing something chunky like rl33, where each kernel weighs around .08 gr, how close do you expect to get even with a beam scale without sorting the kernels by weight?
The Chargemaster and any other autotrickling tool is only as consistent as the scale it's hooked up to. This is partially why the Prometheus series is so coveted and why a Chargemaster or DPS somehow married with a GD503 would blow the doors off of the default setup.
Of all the things considered, I found turning necks really cleaned up some reloading gremlins. Nevertheless, I got to the point where I came to the realization I am a shooter who reloads, Not a reloader who shoots. My reloads shoot well below MOA and I am fine with that. I use the chrono to give me a baseline on velocity, I don't stake my reputation on the number it spits out at me. Sometimes my extreme spread can be off 50-75 FPS. My chrono states an error of + - 1-2%, hell thats over 50 FPS!
I found I was quickly falling down the rabbit hole of reloading. You could chase bench rest consistency for the rest of your life...But I have absolutely ZERO intention of seeking bench rest quality ammo! No offense to the bench resters of course
I found I was quickly falling down the rabbit hole of reloading. You could chase bench rest consistency for the rest of your life...But I have absolutely ZERO intention of seeking bench rest quality ammo! No offense to the bench resters of course
I started with a Chargemaster, and then added a GD503. So now I "throw" .1gn low with the Chargemaster and trickle up on the GD503 with an Omega 2 speed powder trickler. I have seen that by the time I have gotten to 50 rounds, the Chargemaster has started to drift as much as .2gn. It's really irritating when it is on the plus side because then I have to fish kernels out of the pan. The Chargemaster is also holding up production. I didn't mind when I thought it was the source of my precision. I may go to a Harrells "type" powder measure for the first step (don't need THAT much accuracy when I am following it up with the Sartorius, so it will be a cheap knock-off) because it will be much faster.
One thing I learned from a strain gauge vs. magnetic force restoration comparison is that the strain gauge type of scales have electronic filtering to help them settle down quicker, and according to this one source, the filtering can keep it from responding to slowly trickled powder. If that is true (and that was part of my decision to go big with the GD-503, the drifting is not the only source of inaccuracy in the Chargemaster.) I know it used to bother me that sometimes the Chargemaster would trickle for what seemed like forever to reach that last .1gn, and other times it would jump suddenly by .2gn and instantly sound the beep that indicated it had arrived at the right weight. Just didn't feel very consistent. Then again, I could be rationalizing to justify paying too much for a scale.
IMHO the things that have made the most consistent single digit ES/SD are
1. Precise charge weight, I use a Gen2 Prometheus
2. Neck Turning, I know this isn't a popular here
3. Annealing every time
4. Seating by Ojive length
5. Bearing surface, if you really want to know how consistent a brand of pills is measure bearing surface
6. After brass is fire formed, I have found the left over carbon inside case necks just needs to be brushed out, the grey film left over acts as a barrier between the case and bullet, dry lubes must sheer off during the seating process because the most consistent ammo I make has the necks brushed clean, this is also the reason I don't like SS media cleaned brass for my PR brass.
1. Precise charge weight, I use a Gen2 Prometheus
2. Neck Turning, I know this isn't a popular here
3. Annealing every time
4. Seating by Ojive length
5. Bearing surface, if you really want to know how consistent a brand of pills is measure bearing surface
6. After brass is fire formed, I have found the left over carbon inside case necks just needs to be brushed out, the grey film left over acts as a barrier between the case and bullet, dry lubes must sheer off during the seating process because the most consistent ammo I make has the necks brushed clean, this is also the reason I don't like SS media cleaned brass for my PR brass.
Ditto on the 35P. Had a mid priced chrono which was giving me inconsistent data. Replaced it with a 35P and things got much better. Bulky and expensive but works.
Also as mentioned above, sorting bullets by bearing surface will greatly reduce your ES. I use the Tubb's tool as well.
Also as mentioned above, sorting bullets by bearing surface will greatly reduce your ES. I use the Tubb's tool as well.
ES and SD are primarily dependent on ignition and powder burn rates so the first thing to sort out is finding that "right" combination of primer and powder.
Beyond that is the combination of charge weight and internal case dimension. There's no shortcut to an exacting measurement of the charge - however you choose to do it. I throw powder with a cheap Lee dispenser and trickle to weight with the Omega powered unit (great item, BTW) using a digital scale (ever see a Beam Scale in a Lab in the last 30yrs? No.) with resolution to .02 grains and my ES is always 8-15fps with SDs in the ones. (shooting A 6Dasher in F-Open with a 32.82gr load)
My method works and has seen me to multiple match wins including an NRA long-range regional.
I think that bullet sorting (and trimming, pointing etc) as a downrange factor more than a issue in chrono numbers. I can load bullets with a wide spread of bearing surfaces and get the same low ES/SDs but the on-target results at 600 or 1,000 yards will be much worse than those with the same bearing surface length and weight.
Many factors affect what happens downrange but when viewing chrono numbers is helps to remember that we're basically measuring the force of an explosive charge.
Beyond that is the combination of charge weight and internal case dimension. There's no shortcut to an exacting measurement of the charge - however you choose to do it. I throw powder with a cheap Lee dispenser and trickle to weight with the Omega powered unit (great item, BTW) using a digital scale (ever see a Beam Scale in a Lab in the last 30yrs? No.) with resolution to .02 grains and my ES is always 8-15fps with SDs in the ones. (shooting A 6Dasher in F-Open with a 32.82gr load)
My method works and has seen me to multiple match wins including an NRA long-range regional.
I think that bullet sorting (and trimming, pointing etc) as a downrange factor more than a issue in chrono numbers. I can load bullets with a wide spread of bearing surfaces and get the same low ES/SDs but the on-target results at 600 or 1,000 yards will be much worse than those with the same bearing surface length and weight.
Many factors affect what happens downrange but when viewing chrono numbers is helps to remember that we're basically measuring the force of an explosive charge.
I stopped shooting over a chronograph a few years ago. I've had some loads with a low ES shoot terrible at 500 yds and beyond, and I've had loads with a bad ES shoot good out to 1000 yds. Anymore all I do is sight in at 100 yds. then move my target to 500 yds. and start load testing. If I see some vertical dispersion, I adjust my load and try again. Once I find a good load at 500, I move out to 1000 and test there. Not sure what my ES is on any of my three long range rifles and don't really care as they group extremely well. Have you tried to shoot at a mid distance, like 500 yds, and see how it shoots?
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You are getting a lot of great advice here but if you just rely on that Chargemaster and only confirm every 15th throw with your beam scale you are going to be chasing your tail until you correct that IMHO. A couple of others have pointed to the same potential variance. You are using H1000 and it's a extreme powder so that should not be your problem if the charges are weighed the same. I use it in couple of cartridges and I get sub 20ES's with it. Most folks don't want to hear their $300 Chargemaster isn't as accurate as they hoped but if you are chasing perfection in this case it's not the right tool to rely on for every charge even verifying every 15th with a beam. Again, you are stacking variances(like stacking tolerances somewhat) that could result in a 1g swing or more across your loads in a single setting. You could have other issues but you already have the tools and means to correct any weighing related errors then move on to potential other areas of concern if that's not the problem.
L
L
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I really don't know my velocity values, and I have some serious reservations about the validity of ES/SD numbers in the single/low double digits when chrono error factors can be off by as much as +/- 1%, as specified right there in the instructions. For 2500FPS, that number you just read off the display can actually be anywhere within a span of 50FPS. For 3000FPS it's 60FPS, and so on. I prefer to simply X-out that box and move on to concentrating on consistently fabricating the loads.
So what do I consider important?
I weigh each charge, starting slightly low and slowly incrementing the charge in the pan until it just steps over to the desired value and stays there. Takes time; worth every second, IMHO.
I take considerable care to reduce, test, and maintain neck tension. I've covered my methods here ad nauseam; they're unorthodox, actually very antiquated, and who knows if they really mean a damned thing on the target.
As for the rest of it, I leave my die setup as much alone as I can. I value the role the Dillon RL550B's interchangeable toolhead plays in this process.
There are myriad other things I can be doing, and toolmakers who will sell you anything you want to do it with. They did with me, I tried them, tested their individual and cumulative effects, and decided that as a whole, they introduced a complexity that made it just about impossible to rate any single one of them as a plus or minus in the overall outcome.
If you think that accuracy is a simple sum of the most things you can bring to the table, you are totally disregarding the possibility that some things cancel each other out, and others can stack up in an entirely undesirable way.
Every time you introduce another factor, you also introduce the entirely possible likelihood that you can get it wrong; it is pride, and pride alone, that makes us insist we can only get it right, each and every time. The odds do not favor such an outcome; and they become cumulatively worse as complexity grows.
I finally concluded that simplest was best, set them aside, and stuck with just doing the basics with care and diligence.
I'm not winning anything. But that's not in any way a consequence of the way I make my ammo.
Very simply put, this old fart's marksmanship is simply, sorely lacking. I flatly refuse to give up on that.
Greg
So what do I consider important?
I weigh each charge, starting slightly low and slowly incrementing the charge in the pan until it just steps over to the desired value and stays there. Takes time; worth every second, IMHO.
I take considerable care to reduce, test, and maintain neck tension. I've covered my methods here ad nauseam; they're unorthodox, actually very antiquated, and who knows if they really mean a damned thing on the target.
As for the rest of it, I leave my die setup as much alone as I can. I value the role the Dillon RL550B's interchangeable toolhead plays in this process.
There are myriad other things I can be doing, and toolmakers who will sell you anything you want to do it with. They did with me, I tried them, tested their individual and cumulative effects, and decided that as a whole, they introduced a complexity that made it just about impossible to rate any single one of them as a plus or minus in the overall outcome.
If you think that accuracy is a simple sum of the most things you can bring to the table, you are totally disregarding the possibility that some things cancel each other out, and others can stack up in an entirely undesirable way.
Every time you introduce another factor, you also introduce the entirely possible likelihood that you can get it wrong; it is pride, and pride alone, that makes us insist we can only get it right, each and every time. The odds do not favor such an outcome; and they become cumulatively worse as complexity grows.
I finally concluded that simplest was best, set them aside, and stuck with just doing the basics with care and diligence.
I'm not winning anything. But that's not in any way a consequence of the way I make my ammo.
Very simply put, this old fart's marksmanship is simply, sorely lacking. I flatly refuse to give up on that.
Greg
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First things first, cover up the ES button on the chrono. ES is a meaningless number for any practical purpose. If you must use chrono values for something, use SD and fire at least 20 shots before pressing the button. If the value displayed is < 15, you've done all you can do to get a consistent velocity. A Greg stated above, the accuracy of the device is quite suspect in the first place, so what counts is how it shoots. Given a good OCW load, you will have minimal vertical spread with decent loading technique, and you seem to have all the bases covered and then some.
The real question is, what is the actual problem you are trying to solve? Since 98% or so of your shots will be within 3 SD's of the mean, if you see an ES of 34 that would indicate an SD of about 6. Both of these values are well inside the error range of the device. So, what's the problem?
The real question is, what is the actual problem you are trying to solve? Since 98% or so of your shots will be within 3 SD's of the mean, if you see an ES of 34 that would indicate an SD of about 6. Both of these values are well inside the error range of the device. So, what's the problem?
You guys seriously need to stop bring up the "1%-2%" ERROR argument every time a chrono is mentioned. Just because you read or heard that naked figure somewhere, doesn't mean it applies to your cause.
That figure means that the device might be that far off from the TRUE velocity, not that that's how much error is between shots. So you might shoot a round over 3 chronos that each read 2720,2710,2690 while the true velocity is 2 700 . However that round going over the same chrono again and again will continue giving that same number (or very close to it, as there will be possibly some slight error).
If there was a possible error of 30+ fps in EVERY shot like you guys like to imply, chronos would be useless and not used by any of the elites or bench rest reloader.
Somehow, no matter what chrono I have run my load over (oheler, M2, magneto etc) my 308 load has always been under 10 ES (closer to under 5). But your right, I'm sure each time, out of the hundreds of rounds, it's just a coincidence that the ES was lower than the claimed error factor.
Stop spreading misinformation, they might not be 100% accurate but they are very precise. As high school sciences should have taught, there is a difference.
That figure means that the device might be that far off from the TRUE velocity, not that that's how much error is between shots. So you might shoot a round over 3 chronos that each read 2720,2710,2690 while the true velocity is 2 700 . However that round going over the same chrono again and again will continue giving that same number (or very close to it, as there will be possibly some slight error).
If there was a possible error of 30+ fps in EVERY shot like you guys like to imply, chronos would be useless and not used by any of the elites or bench rest reloader.
Somehow, no matter what chrono I have run my load over (oheler, M2, magneto etc) my 308 load has always been under 10 ES (closer to under 5). But your right, I'm sure each time, out of the hundreds of rounds, it's just a coincidence that the ES was lower than the claimed error factor.
Stop spreading misinformation, they might not be 100% accurate but they are very precise. As high school sciences should have taught, there is a difference.
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Oh really? Misinformation? Read your chrono's instruction booklet to find the "somewhere" for where those "naked figure"s originate.
Additionally, 20+ years as a systems programmer, and another dozen or so as a paid independent I/T consultant have given me a clear understanding of what an error factor truly entails. Solid state components obey human-derived programs which have limits governing data field sizes and rounding that impose cumulative levels of imprecision in computation outputs. Of course more precision can be derived, but this entails orders of magnitude that make such precision more expensive than most of us can afford in consumer electronic devices. Uncle Sam can afford such precision when developing hardware with nine and ten digit price tags, but you and I are limited to affordable implements with their lesser degrees of precision. Be happy we can get what we have, and stop telling retired professionals how to do their lifelong specialty.
An error factor means precisely what it says. Any and every reading displayed has an equal chance of being wrong by any value up to and including the error value limit, both plus and minus. There are no trends, and no reading is in any way related to any other displayed. Hanging one's hopes and plans on numbers that are precise to only fractions of the error factor is simply ludicrous. But please feel free to do it if you absolutely must; I have no desire to stand in your way, dear friend.
Greg
PS, Just got your PM, and I can only apologize for taking your post the wrong way. But, in the same token, I cannot simply defer. Error factors are a crucial misunderstanding where chronographs are concerned, and numbers that ignore their limits are functionally meaningless. No matter how often or how clearly I try to explain this rather simple fact, I will probably always encounter folks who feel a need to swim against this current. I can't seem to convince them otherwise, and as of this post, I shall no longer try; this too is pointless.
I can't put claim to being a shooting elite. I'm sure they exist and I am equally sure I am not one of them. They use chronographs well and wisely. I suspect, however that one might find some reluctance in them to speak of their outputs in absolutes, especially ones with such unswerving claims of precision. I would consider that a wise approach to such matters. I see miniscule ES/SD numbers being bandied about here occasionally, and I take them with a grain of salt, but would I lay claim to such? No.
As a programmer, whenever I multiplied/divided/added/subtracted two rounded numbers, it was a given that the (at least) last two digits of that computation were meaningless (as in..., is it really a 6, or is it a 7, or a 5...?). Do that enough times, and precision become rather debatable.
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Just to clear things up (and this is what I said in my PM). My post was not meant to have a smartass tone or to be disrespectful. I just strongly disagree and am tired of always seeing this posted on here.
I never said the chrono numbers are absolute and that they are the end all for load development. Absolutely not. Its the results down range that matter the most. I think we can both agree on that.
Anyways. I guess at the end of the day we can just agree to disagree and everyone make their own informed decision based on their experiences.
I'm fine with that, and as I said, really don't wish to discuss such issues ever again. In the meantime, I certainly mean you no offense and take none either.
Greg
Greg
Greg - Thanks for the clarification on chronograph error. I've heard it alluded to from time to time in various chronograph discussions but it was never explained as well as what you posted.
Chris
Chris
I called tech support for the chronograph I own.
According to them, If I were to test 100 theoretical reloads through my device, and each round fired had the exact same velocity, independently, each round fired would have the same probability of a + or - .5% error in the displayed velocity I see on the screen. So yes, I overstated my error probability.
Now, each shot, independently could have a .5% error up or a .5% error down ( I have no way of knowing which) at 2700FPS thats a total 27 fps. For someone to have under 10 ES and claim closer to 5..."Always"...Well, my hats off to you.
Stating that I have a 27 ES error factor with my chrono is not spreading misinformation. Seriously.
According to them, If I were to test 100 theoretical reloads through my device, and each round fired had the exact same velocity, independently, each round fired would have the same probability of a + or - .5% error in the displayed velocity I see on the screen. So yes, I overstated my error probability.
Now, each shot, independently could have a .5% error up or a .5% error down ( I have no way of knowing which) at 2700FPS thats a total 27 fps. For someone to have under 10 ES and claim closer to 5..."Always"...Well, my hats off to you.
Stating that I have a 27 ES error factor with my chrono is not spreading misinformation. Seriously.
I am at least partly responsible for that allusion(?). It took until now for me to slip my mask as an elder retired fart and state actual specifics. I apologize for not doing so earlier. Be careful not to blink, because it will probably never happen again.
Greg
Greg
Well then I stand corrected for the time being. Can't be right 100% of the time!
Something still doesn't jive with what your tech support guy is saying and what I'm actually seeing. So I will persomally look into this by contacting other manufacturers and see what they say. Most tech support agents are usually nothing more than someone reading a script... Real life results don't always follow 'theory' and 'claims'. Also would be interesting to see what level of confidence they are resorting to, to get that .5% number (this makes a huge difference, to what their claim is vs what is realistically seen)
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Just to clarify.. If this information is correct. This implies that someone's load that receives a SD of 10, can in actuality have an SD of 25. And any of the reloaders on here that change a couple things and see drops of SD by even 10-15, cannot actually use this information because it would be an insignificant amount of change and would fall into the error factor... I guess it's been coincidence all along that turning necks or uniforming primer pockets lowers SD (excuse the sarcasm, but if this doesn't tell you something is fishy about the error claims, I don't know what will)
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At the end of the day...only a hit down range will confirm any thing we type on the internet of hear over a telephone. See ya, I gotta get my weekend started!
Guys; I agree completely, which is why I put my faith in the target instead of in the chrono.
The chrono may lie, the chrono may be right on the money, or the chrono may even be blowing smoke in our collective face. Personally I don't care which, but I'm pretty sure the target is telling me something I can probably trust a whole lot more. But I don't trust even that completely and try to shoot a statistically significant number of sample groups.
These days that's harder to do with the shortages, but I will still insist on at least a pair of five shot groups at each increment before I proceed to the next stage of increments.
Greg
The chrono may lie, the chrono may be right on the money, or the chrono may even be blowing smoke in our collective face. Personally I don't care which, but I'm pretty sure the target is telling me something I can probably trust a whole lot more. But I don't trust even that completely and try to shoot a statistically significant number of sample groups.
These days that's harder to do with the shortages, but I will still insist on at least a pair of five shot groups at each increment before I proceed to the next stage of increments.
Greg
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Totally agree as well. I've had 338 loads during development that produced phenomenal SDs but did horrible down range. Just one piece of the puzzle... What happens down range is what's actually important
Greg, I respect the fact that you appear to have been contributing to this site for a very long time; however, I have to disagree on two points. First, you must be referring to one of the cheapie chronographs that initially drove me crazy. The Oehler 35P specs say that at 3000fps and the standard four foot spacing, it is accurate to 4fps. http://www.oehler-research.com/specs.html
For the second item, it is a mild disagreement, as I not only love my 550B, but according to Glenn Zediker, David Tubb relied on two 550B presses for his 11 Camp Perry wins. (Of course, he had mounted a Gen2 Prometheus on one of them!) But, specifically mentioning the tool heads. Those that come with the 550B are junk. They are cast aluminum with no machining other than the threads. I use 5 Whidden Toolworks Floating Die 550 Toolheads with a Toolhead Clamp Kit pre-installed https://www.storesonline.com/site/696296/product/T1389 which I got by way of UniqueTek.com. It is CNC machined and has an arrangement where two of the dies float, and I get it through UniqueTek because they add their Toolhead Clamp which locks the toolhead in position in the 550B.
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427Cobra, from what I know so far, your advice sounds quite sound. I have already started on some of it, as not being able to find a Prometheus, I have settled for second best in a GD503. I have a few questions for you though. Your second item was neck turning. Is that a one-time thing, and if not, how often do you re-turn the necks. I would think that brass flowing up into the neck would affect the neck thickness. +1 on the bearing surface. I was shocked by the variation on relatively reliable SMK boolits. I sorted 1000 77gn SMK bullets by boattail to Ogive and found an ES of .018". I may need to bite the bullet (pardon the pun) and get Scenars. My other question is on your last point. Are you saying that cleaning brass with stainless media harms accuracy? Does it help that situation if you anneal after cleaning the brass (since you mentioned a carbon film inside the neck, and annealing may leave some carbon there.
p.s. I just heard from Doug Giraud's wife (she apparently handles the business end) and my annealing machine will be ready TOMORROW! New Page 1 I'm going out there to pick it up.
rsplante;
In the first instance, my reference was made regarding the Chrony Beta, and your experiences appear to parallel mine rather closely. If Oehler cites a 4PFS accuracy for their 35P, I'm inclined to believe them (and you). I think it's refreshing that the state of the art has risen to such a higher level. It has restored my faith in chronographs to the point where I am again interested in owning one (that actually works; I am currently staring at two Chrony's that don't....). As funds permit, I will be following up on this ($525 plus shipping is not that easy to muster these days).
In the second instance, I reviewed the attached link, and thank you for including it. The included information is illuminating and convincing. The device may have less utility for me because I use basic die sets and shoot with SAAMI chambers in all but one instance. I also have rather fewer reservations than some about the design intent of the Dillon's floating die head. But it would be obstinate of me not to at least try one out and see its potential. Again, as funds permit, etc.
Thank you for your thought provoking post.
Greg
In the first instance, my reference was made regarding the Chrony Beta, and your experiences appear to parallel mine rather closely. If Oehler cites a 4PFS accuracy for their 35P, I'm inclined to believe them (and you). I think it's refreshing that the state of the art has risen to such a higher level. It has restored my faith in chronographs to the point where I am again interested in owning one (that actually works; I am currently staring at two Chrony's that don't....). As funds permit, I will be following up on this ($525 plus shipping is not that easy to muster these days).
In the second instance, I reviewed the attached link, and thank you for including it. The included information is illuminating and convincing. The device may have less utility for me because I use basic die sets and shoot with SAAMI chambers in all but one instance. I also have rather fewer reservations than some about the design intent of the Dillon's floating die head. But it would be obstinate of me not to at least try one out and see its potential. Again, as funds permit, etc.
Thank you for your thought provoking post.
Greg
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Now that sounds more right. All is right in the reloading world once again! Thank you for finding some solid evidence before I.
Also, correct me if I'm wrong but this chrono has actually been out for a long time and the internals have actually not been updated or anything. They stopped making them at one point and just started back up where they left off.
It would be interesting for someone to compare the accuracy of the Oehler to the new magneto speed. The magneto speed should be inherently even more accurate.
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You are correct about the 35P being long-in-the-tooth. You could even say that it is Chronologically Gifted. It has been around at least since the 70s and that shows up in places like the printer which one person described as looking like it came out of a government warehouse of Korean War surplus, but we have a saying in Texas, If it ain't broke, don't fix it. If you search, there was recently a back and forth on this very webside between Oehler and Magneto Speed adherants. I will present the Oehler side (since I do not actually own a magnetospeed) and will leave the Magnetospeed argument to owners of that piece of equipment.
The pluses for the Oehler are that while unwieldly, the four foot spacing allows for much more accurate timing. If you think about it, a 3000 fps bullet covers that distance in .001333 sec. The Magnetospeed looks to me to be about 9" long which means it will only "see" an equally fast bullet for .00025 sec which immediately puts the electronics at a 5.33X disadvantage. I also like to combine ladder tests with chronographing my shots. Anything you attach to the end of your barrel, such as the Magnetospeed, simply has to have an effect on the accuracy of the rifle. Third, I plan on starting to compete in 3-gun competitions, and need to know the speed of my bullets for figuring power factor. You cannot attach a Magnetospeed to an automatic pistol. Fourth, and probably most important, the Oehler is what is called a Proof Chronograph. It makes two measurements for each shot. The main measurement is made at 4 ft, while a second measurement is made after 2 ft (there are three detectors). The two measurements are compared in software and the printer flags suspect measurements (both numbers are presented by the way.) Fifth, in the manufacturers words, "The serious shooters at your club range probably use Oehler systems. Browse through gun magazines and you read about Oehler chronographs. Walk through any commercial ammo plant and you find the test bays lined with Oehler instruments. Behind the high fences of most government arsenals and proving grounds, you find them testing with Oehler equipment."
OK, I lied, I will present what I know that's positive about the Magnetospeed. It is MUCH easier to set up and use. You simply strap it to the end of your barrel. It does not require waiting for a cease fire so that you can go downrange 10-20 feet to set it up. It is easier to carry and store. It is not affected by variations in sunlight (although I have not experienced any problems in that area with the 35P yet.) So it seems to me that if money is no object, you should get both; however, if you cannot justify/afford both, in my humble but accurate opinion (lol), the Oehler still gives better results.
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Well the length of the system is irrelevant. It's only relevant when you are talking about the same system. The longer the chrono, using the same system, the less % small errors extrapolate to. But without knowing the processing speed and power of the two separate systems, it's impossible to know if length alone makes its advantageous.
When I said inherently more accurate I was referring most importantly to the fact that the magneto works based of magnetic/field principles while the Oehler is based on optical sensors, which are generally much less accurate (think about how different light conditions alone changes fps readings).
I agree with you that it sucks that you have to hang it off the barrel and have it effect your ocw and load development. That's why I'm keeping my M2 chrono just in case.
Anyways, we are getting off topic from the OP. Thank you for all your input on the side topic I started!
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Question more than a comment here. Aren't the bullets just tripping 2 sensors in each case? They aren't 'seeing' the bullet throughout a window of time as this seems to describe. It should make no difference how long it takes the bullet to traverse a distance, trip 2 sensors and then measure the time it took to traverse that known distance to calculate velocity.
L
edt: And on the original topic I still think a lot of the variation in ES lies in relying on the Chargemaster to throw charges and only confirming every 15th throw with the beam. JMHO.
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Greg, I hate to be the bearer of bad news, but there's been a price increase. "The complete system price is $575 with $20 shipping for domestic UPS ground." Then people like me that live in TX have to add $47 sales tax.
Thank you for the compliment. I also enjoy your posts.
Your idea is 'theoretically' sound; however in the real world there are a couple of reasons the distance between sensors is important. First off, If you place your sensors 2 feet part and you are off by 1 inch (for one reason or another), your FPS will be off by as much as 100+fps!While if you are off by 1 inch and the sensors are 8 feet apart, you will only be off by 26 fps. So length helps spread out errors introduced into the system. Next reason, the optical sensors have a specific cycle rate (Kind of like how some video cameras capture video at more frames per second than others). So right away the EXACT time the bullet passed will be fudged by a little bit, depending on that cycle rate. Lastly, software is usually programmed to have an X amount of significant digits during its calculations. The larger the number (time it takes to get from one sensor to the other) , the less gets cut off, however I doubt this has much effect.
Now to the OP. I agree with Layton that the chargemaster definitely effects ES/SD. When I manually weighed every charge, I got better ES/SD numbers than when I used the chargemaster. It was only barely worse, but there was a repeatedly measured difference. Even though it hindered ES/SD, it did not seem to effect accuracy down rage, so now I use my chargemaster exclusively. The only things I did to help was installed all the recommended mods and re preogrammed it. Then whenever it throws a charge I lift it off the scale slightly and set it down. Most of the time it is the same weight. Every once in a while I catch an overthrow this way, that otherwise didn't register as an overthrow.
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I believe it is due to rounding errors etc. Think about an extreme case, if you were able to place the detectors 100yd apart, do you think (other than the bullet slowing down) that you could get a more accurate measurement? In any event, I am mostly relying on the OEM's numbers:
Sorry about the size. Double click and it will open in another window.
LOL, So what we need to do is take my Magnetospeed, strap it to one of our barrels and shoot through your Oehler and compare the delta's. You get to do the write up.
L
L
See now you're applying that real world stuff again.
Actually just curious to see how close they are. No way to tell which one is right if they are far apart.
L
Actually just curious to see how close they are. No way to tell which one is right if they are far apart.
L
