Runout...can it be a measured on paper at 500-1000 yds?

[dmoran]

Several years back, did some run-out testing in 243-Ackley's at 500yds. Don't have the results any more but formed the opinion that run-out mattered less when seating close and/or in the lands.

I periodically check run-out, in part to judge my own skills as a reloader to how well I can make my ammo, setup dies, and maintenance my reloading equipment.

For these reason's run-out matters to me.
Donovan

 

[MattPeetz]

No it can't be measured on paper.

 

[Richard Coody]

No it can't be measured on paper.

maybe not for every shooter/rifle but it can be for me

 

[liseo]

I dont know the answer, but if runout don't matter, why the gunsmith strive to get the chamber aligned with the rifle bore? The effect of misaligned chamber relative to the bore is not the same as a misaligned bullet?

or has anything to do with one thing with another?

 

[Intheshop]

Learning how to process zero bullet run out will pay benny's down the road....just sayin.

In cast bullet world,it does show up,on paper,rather quickly.These are med to hard jams.

 

[.22gongzilla]

It matters when using an undersize neck.

 

[jlow]

So far, all I have seen is a bunch of subjective "yes it does" with no proof what so ever being provided. This of course is what you OP should expect because in order for proof to arrive, all the testers will first have to proof that they can actually hold ALL of the other variables (they know of, and those that they don't) constant, and show their group size is always reproducible BEFORE testing for effect of differences in "runout"....

 

[Richard Coody]

So far, all I have seen is a bunch of subjective "yes it does" with no proof what so ever being provided. This of course is what you OP should expect because in order for proof to arrive, all the testers will first have to proof that they can actually hold ALL of the other variables (they know of, and those that they don't) constant, and show their group size is always reproducible BEFORE testing for effect of differences in "runout"....

opinions vary

you are most certainly entitled to yours

i follow this procedure and i have proved to my satisfaction that runout does make a difference


start with quality brass. i prefer lapua.

neck turn to a consistent neck thickness

anneal often and consistently

leave the carbon in your necks

use a quality full length resizing die. custom is best but there are alternatives

finish up with a neck sizing mandrel for final fit. K & M makes a nice kit.

to verify that your neck tension is consistent use a K & M or 21st century arbor press with seating force indicator

and finally sort by concentricity with a 21st century concentricity gauge.

perfect rounds shoot in the 1's culls shoot in the 2's

 

[BenPerfected]

So far, all I have seen is a bunch of subjective "yes it does" with no proof what so ever being provided. This of course is what you OP should expect because in order for proof to arrive, all the testers will first have to proof that they can actually hold ALL of the other variables (they know of, and those that they don't) constant, and show their group size is always reproducible BEFORE testing for effect of differences in "runout"....

Going to shoot a series of 5 shot groups at 500 yds tomorrow. To test, will be shooting 6 Dasher groups with the only significant variables being RO and the wind. The testing will be comparison using ammo sorted in 2 groups. The two RO groups will be: .000-.003 and .004-.008. Will post the group results shortly.
Ben

 

[mikecr]

Going to shoot a series of 5 shot groups at 500 yds tomorrow. To test, will be shooting 6 Dasher groups with the only significant variables being RO and the wind. The testing will be comparison using ammo sorted in 2 groups. The two RO groups will be: .000-.003 and .004-.008. Will post the group results shortly.
Ben

Please also qualify the test w/resp to chamber clearance/case fit & seated relationship to lands.
Thanks

 

[Richard Coody]

it will be an interesting test. my thoughts is at 500 yrds wind calls will rule.

i tested at 100 yrds on a calm day. i found a difference of 0.10 between perfectly concentric rounds and culls with less than .003.

of course the brass had been weigh sorted, neck turned and annealed after fire forming. the bullets had been weigh sorted and sorted for length of bearing surface the carbon was undisturbed in the neck, custom full length sizing die was used case was charged with the autotrickler system, bullet seating was done with wilson dies and the 21st century shooting hydro press and rounds were sorted by seating force. final sort was done with a 21st century concentricity gauge. i am sure there is more i am kind of obsessive trying to find what works and what is unnecessary.

this is what i started with

and this was the final result after all of that

 

[BenPerfected]

Please also qualify the test w/resp to chamber clearance/case fit & seated relationship to lands.
Thanks

Too many variables for one test, will be shooting a load/tune that can shoot a consistent 5 shoot 500 yd group 1.5-1.75 with light winds. Will post the results tomorrow if the wind is reasonable.
Ben

 

[MattPeetz]

The test will be invalid if you know which load your shooting.
You can't know which load your shooting. Someone should be handing the cartridges from behind you so you can't see them.
The test should also be shot using a pit so someone can mark and keep track of the shots so the shooter can't keep track. This way all shots can be shot on a single target. Or an ET target should be used.

 

[.22gongzilla]

Standard unfinished case with varied neck wall thickness will not allow chambering with undersize neck. Not subjective IMO just a practical matter.

 

[jlow]

Doing a meaningful and statistically significant test is difficult and I will explain why.

Let’s just say you shoot two 5 round groups. One with rounds with almost perfect concentricity and the other 5-10 thousands off and you find a difference, let’s day the perfect concentricity stuff shoots one hole whereas the other with 0.5 MOA, you would think this is pretty definitive? The answer is no.

The reason is what you have basically done is conducted an N=1. This is statistical talk that means you have only tested it one time.

So this is like someone comes up to me and said I have a method so that when I flip a coin, I can make the head always come up on top. He flips it and sure enough – heads on top. So here he has done a single test N=1.

So if say if I was thinking of using this guy to make some easy money and I want to bet big, will I be convinced that he really can always flip heads up? Well obviousely not, at least to me, he is going to have to be able to do this consistently many times, at least 5-10 times with NO failures. Even then...

So this is the same thing with the round testing, one group against one group one time we know can happen just by chance. How many times you have shot a great group but cannot reproduce it? We all know the answer to that. So to be believable, I would think you would have to do it multiple times and it would always have to work out like the first time.

Lots of time, lots of ammo especially if the difference is small i.e 0.1 to 0.2 MOA difference.

And we have not talked about shooter bias as MattPeetz correctly pointed out if the shooter knows which type of rounds he is shooting i.e. it must be done blind. Might sound like mumbo jumbo to people but the effect of bias in test is very real.

If you think I am some statistician or math head, think again, I really dislike stats when I was in college but working in real life teach me the importance of statistics to avoid running around in circles....

 

[chkunz]

jlow, thanks, I hope folks will take a serious look at what you are saying. For those that have had some exposure to statistics this is easier to understand. I wish we had more folks who have the knowledge to do more teaching on this subject. Some times opinions are all we have but openions are no substitute for data and analysis.

 

[jlow]

I am glad to try to put some meat into these talks of prove.

Statistics is definitely not my thing since I am a biologist and at work they hire real statisticians to help people like me. After having it hammered into my head a few hundred times, some of it rubs off. My comments is not to give an experts view of how to, but to give people a glimpse at what real meaningful proof really involves.

 

[dkhunt14]

jlow, thanks, I hope folks will take a serious look at what you are saying. For those that have had some exposure to statistics this is easier to understand. I wish we had more folks who have the knowledge to do more teaching on this subject. Some times opinions are all we have but openions are no substitute for data and analysis.

But if you shoot a match over and over with 10 round records. If you take 5 run out and 5 zero run out and color 5 blue and 5 red and shoot in any order by randomly putting them in your block. No way can you influence this and in 2 or 3 matches it will show you which one is better. Matt

 

[chkunz]

Matt, it sounds like you have a great plan to obtain data that can be statistically analyzed. Share the data from your shooting as you describe and we can ask folks that have the statistical skills to analyze and we can report results. I have done some work with this type analysis and probably can do the calculations but would welcome others that may be more qualified to lead on this. This is exactly what we need to do to replace opinions with statistical analysis. If you can provide scores with high runout and scores with low runout I will help with the calculations. Doing the test "blind" would have its advantages but if this is not feasible do not let that be a deterrent, just get us the data and we will do the rest. Take care, Clyde

 

[dkhunt14]

Matt, it sounds like you have a great plan to obtain data that can be statistically analyzed. Share the data from your shooting as you describe and we can ask folks that have the statistical skills to analyze and we can report results. I have done some work with this type analysis and probably can do the calculations but would welcome others that may be more qualified to lead on this. This is exactly what we need to do to replace opinions with statistical analysis. If you can provide scores with high runout and scores with low runout I will help with the calculations. Doing the test "blind" would have its advantages but if this is not feasible do not let that be a deterrent, just get us the data and we will do the rest. Take care, Clyde

There are so many variables involved that can change things. I believe seating depth to be one. If I am shooting in the lands and another is shooting off the lands, I think the results would be way different. I don't believe my data would then help the other shooter. In my results, I believe in the lands doesn't affect it as much. If the bullet is in the lands, it would get straightened. Whereas if off, it wouldnt. I think everybody would have to test for themselves. Possibly even bullet type or caliber would change the results.

I was giving an example of how it could be tested without shooting hundreds of rounds. The colors show up real well on target and if one was better then the other, it would be seen in a few targets by the fliers or outliers. By shooting them at random the results would be less chance of error by conditions, especially if they repeat on multiple targets. It would be way better then shooting two groups at two different times when conditions could change the results. Matt