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Using chronograph data to choose a load will not always yield the best long range load....Simply because it performs the best statistically, doesn't mean it will shoot the best on paper. True. Has happened to me mostly with Imr 4064 in several cartridges.
"I never thought I'd live to see the day that a U.S. president would raise an army to invade his own country."
Robert E. Lee
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GD, no one ever said they use a chronograph to determine the load, just that it is better at determining load-to-load velocity differences. Never had a piece of paper tell me the velocity of my load.
Point was the ladder/OCD are NOT for determining velocity differences, they are for determining nodes of your rifle barrel vibration/oscillation. And they don't just move up and down... So you can't "ignore" horizontal dispersion.
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Agreed, but is horizontal never caused by barrel harmonics?
I always thought barrels (free floated mind you) vibrate in a figure-8 pattern. Can't seem to find that article.
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Campfire 'Bwana
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Yes, someone that gets it. I always go with best paper results, rather than best chrono results.
Chrono has its uses. But not for load selection. I don't know squat about this ladder stuff, but I can't imagine working up loads without a chrono. I don't think he's saying he works up loads without a chrono. Just that he doesn't pick the most accurate load based on chrono results.
A wise man is frequently humbled.
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Yes, someone that gets it. I always go with best paper results, rather than best chrono results.
Chrono has its uses. But not for load selection. I don't know squat about this ladder stuff, but I can't imagine working up loads without a chrono. I don't think he's saying he works up loads without a chrono. Just that he doesn't pick the most accurate load based on chrono results. I can't remember the last time I used a chrono during load development. I usually only use one if I'm working with unknown powders with no data, just to see if they will give me the velocity I want. Determining the velocity is pretty simple when using a Ballistic program at the range. If I'm shooting a 600 yard ladder, I look at velocity data for other powders I feel are close and dial to 600 accordingly. Adjustments are made and noted to the program's velocity figure until the amount dialed corresponds with velocity. After the ladder is done and I've finished the load, I know an estimated velocity. I then shoot steel at different distances up to 1 mile, adjust velocity in the program to give the actual data dialed... Done.
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Ric and I have already had this conversation.... but I'll submit it to the group:
If ladders "are for determining nodes of your rifle barrel vibration/oscillation"...... How come ALL my rifles are equally as accurate with the 14oz, 9" long, suppressor attached as they are without it? Admittedly, it is always to a lower POI... but the accuracy has never decreased when the can is attached.
Shouldn't the addition of all that weight/length on the end of the pipe do some wonky stuff to my osculation patterns?
Just wondering.... because I think there's a different explanation to why the ladder developed loads seem to be more stable. I'm not nearly smart enough to figure out what it is... but I'm not buying the "osculation theory" entirely.
You better pray to the God of Skinny Punks that this wind doesn't pick up......
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Might be an interesting test to do, but I already know the answer. Try hanging a weight off of your barrel and shooting groups to compare accuracy. Anyone who shoots any precision type stuff knows that if you stick your barrel through a port on a barricade and rest the barrel instead of the stock on something, accuracy and point of impact goes to chit. I know first hand that using the Magnetospeed chrono which hangs off of your barrel fugs up your groups. Never use one during development! I have a buddy who had a laser beam .223 WSSM. He then wrapped camo tape around the barrel and it turned into a shotgun. Barrel harmonics happen.... 
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I hung a 14oz weight off the end of the barrel.... as described above, on a number of guns.... it has never hurt accuracy....
How is that possible?
You better pray to the God of Skinny Punks that this wind doesn't pick up......
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The people wringing their hands over Trump's rhetoric don't know what time it is in America.
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Luckiest guy I know..... you know my girl....
But.... I don't know anybody who shoots a different load suppressed than they do unsuppressed..... do you?
If NOBODY changes loads when they add the can..... and the gun shoots the same.... then it stands to reason that something other than "harmonics" is mostly responsible for the consistency that Audette loads produce...
You better pray to the God of Skinny Punks that this wind doesn't pick up......
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No I don't. Suppressors don't seem to affect accuracy like you say, but POI, yes.
I do know that the other examples I gave do.
The people wringing their hands over Trump's rhetoric don't know what time it is in America.
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![[Linked Image]](http://i379.photobucket.com/albums/oo236/rcamuglia/upward-downward-slope-1.png) Harmonics are totally responsible for accurate loads. The entire purpose of the Audette is to isolate the exit time where harmonics are correct for accuracy. Ever hear of a barrel tuner? What do you think it does? It's nothing more than an weight adjustable for length. SUMMARY.... For the reader who doesn't want to wade through all the discussion here is a summary of what a tuner can do to correct for small variations in muzzle velocity from round to round. The Muzzle Projection Curve shows where the muzzle is pointing at a 100 yard target while the rifle is being fired. The most important aspect is the curve is where the muzzle is pointing at the time the bullet exits the muzzle. LADDER TEST.... It appears that the "Muzzle Projection Curve" (MPC) plus the Muzzle's Vertical Velocity that is imposed on the bullet at muzzle exit time tends to shed some light on what is going on in the Ladder or "Audette" test. The Ladder Test uses loading to generate a series of loads with increasing velocity shot at the same target to see if some of the rounds print at the same POI even with different velocities. If a convergence is found, then loading in that range of velocity should shoot tight groups even with slight velocity variations. The following calculations were done to find the Point of Impact (POI) at a 100 yard virtual target. In the field, it is typical to shoot the Ladder Test at long range. One thing the 300 yd Ladder Test does it that it amplifies the bullet drop more than where the muzzle is pointing. The muzzle pointing is line-of-sight and therefore linear but the bullet drop during the Time Of Flight (TOF) is not linear with distance. With the calculation it is possible to calculate the POI even if they are close to each other, so 100 yards was used. Read this entire page and hopefully you'll start to understand.... http://www.varmintal.com/aeste.htm
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Funny how that phenomenon doesn't apply to suppressed rifles.....
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Funny how that phenomenon doesn't apply to suppressed rifles..... I'd say it does, but may not be as noticeable. Anything suppressed generally has a big heavy barrel. If anything, the weight of the suppressor dampens the barrel harmonics. A friend just put one on an AR chambered in .260. It shot 1 1/4" groups without the suppressor and One-Holes with the suppressor. Most suppressed barrels are heavy axle rods in the first place.
The people wringing their hands over Trump's rhetoric don't know what time it is in America.
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There is some 22 benchrest guy who had a theory on tuners for 22's that seemed to work for his guns. Essentially his tuners put a calculated amount of weight out past the muzzle of his guns. He also had some thoughts about barrel harmonics and ringing the barrel that he wrote up in a magazine.
Might be Bill Calfee, but I'm not sure about that.
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Dogshooter, I think you should test your theory by shooting your can on a less than optimum load.
I have a hunch it will be significantly worse.
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Dogshooter, I think you should test your theory by shooting your can on a less than optimum load.
I have a hunch it will be significantly worse. Who gives a schitt? A bad load is a bad load..... but you're wrong. Ric sites an example above of a rifle going from 1+ MOA to a one hole gun when the can was added. Also.... I've had several marginal loads that shoot much better through the suppressor. Accuracy has always held or improved... If the Audette relied solely on harmonics..... then a good load without the can, wouldn't still shoot as well once the can was added..... because the added weight/length necessarily changes the harmonics. Who changes to a different load once they add the suppressor? NOBODY..... why?
You better pray to the God of Skinny Punks that this wind doesn't pick up......
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I'm sure you've heard of the BOSS System. Have you ever tuned a rifle with one?
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I've used a QUE tuner, which works on the same principal as the BOSS. It worked well, making a 1.25" load into a .6" load within about 4 adjustments. Worked as advertised but was VERY loud and I finally got tired of the looks.
John
If my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then I will hear from heaven, and I will forgive their sin and will heal their land. 2 Chronicles 7:14
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