concentric ammo VS ammo with run out ?

[zap]

Has anyone ever done an actual test with good concentric ammo against ammo that has significant run out, say .008 ?

If so, explain your results please. I am wondering, in a good shooting gun, (one that shoots consistant two's, threes or better), if you can see a difference.
Do you have any pics of targets to verify your findings ?

 

[zap]

bump

 

[markm87]

We sorted off some 168gr SMKs from my handloads that had .006-.008 runout... About 5 or 6 of them if I remember correctly.

I got all excited to see a group that just openned up big time.... but they actually shot almost as good as the ammo with .003" or lower runnout. (I'd say they were inside 1 MOA at 100 yards) I shot them with low effort on accuracy on my part thinking they would be terrible.

Not sure if that would hold true for Secant ogive bullets too... but I was surprised to see how well they shot.

 

[BoydAllen]

In order to really see the differences in group size that are solely caused by differences in ammo straightness, the load has to be perfectly tuned, and fired in a rifle of high accuracy, carefully. For many situations that do not meet this standard, the differences will be largely "lost in the noise". On the other hand, for competition, where every little advantage is potentially important, that is another matter. Sounds like you need to do some testing. For competition benchrest I have been told that runout, that is measured on the bullet, some distance from the front of the neck, that anything under .002 is indistinguishable on the target. This may be because with thin necks, light tension, flat base bullets with pressure rings, and seating into the rifling, that simply chambering the round straightens it to some degree. Are you shooting a very accurate rifle over wind flags? Ammo straightness is the result of the dies being used. If you want to make it better, use better dies.

 

[dozernomore]

I'm not a bench rest shooter by any means,I do hand load and have been hand loading for three years.When I do load development,I use the same mfr of brass,usually winchester,I measure each brass,measure each bullet and always measure each powder drop.I also use the ladder load development and when I can get 5 rounds 0.5'' or less,I'm happy.When hand loading,I always measure concentricity.anything over .004'' I mark on the brass what it measures,I will use these rounds for fouling shots .but not for initial load development. When I have found a good load and proceed to load 30-40 rounds I measure the concenticicity and the rounds that are .005''-.008'' I have shot at the range at 100 yards,my moa is still 1'' or less.So actually there is not a big enough difference with excessive run out and the moa of predator's and varmints that I shoot.If I'm gonna take a poke at something past 300 yards I'll probably use a low run out round though.

p.s. my rifles are all factory
rem 700 sps varmint 22-250
rem 700 sps varmint 243
savage mdl 25 204ruger
savage stevens mdl 200 223
and they all shoot under moa with the right hand loads

 

[aJR]

Hi Zap , I have done tests at 1000yds on runout .. My die produces a max runout of 2.4 thou over 100 loaded cartridges ,.. Most will be only 1 thou but it varies in no particular pattern.. In these tests at .002 i could not shoot the difference on target ,but at .003 i could see the group open up .. This is with a 30cal cartridge 3.700 in AOL.. Doing a blind test saw the offending .003 and larger round leave the group in any direction ,including against the prevailing winds .. I still today straighten every round to less than .001 because of these tests .. If 2 is better than 3 ,then 1 must be even better , 'sides ,there's nothing on TV anyhow ..JR..Jeff Rogers

Has anyone ever done an actual test with good concentric ammo against ammo that has significant run out, say .008 ?

If so, explain your results please. I am wondering, in a good shooting gun, (one that shoots consistant two's, threes or better), if you can see a difference.
Do you have any pics of targets to verify your findings ?

 

[dreever]

I sort by runout as follows:

0 to less than .001 saved for targets 300 meters and beyond
.001-.002 used for targets 100-200 meters
above.002 sighters and foulers.

How much of a difference does it make? It helps the head game which is a big part of competition. If you just know that your equipment and ammo is the absolute best that you can come up with that's just one less variable to worry about.

Danny

 

[zap]

Thanks all,
great answers. I was just curious. Don't do any competative shooting.

 

[xdeano]

I was always told that .000 to .003 are good, anything over goes into practice ammo.

xdeano

 

[necchi]

Has anyone ever done an actual test,,,

Yeah I did, when I first began loading the guy's at the local shop where trying to sell me a concentricity gauge, they asked me to bring in some ammo the "cherry-pick" on their gauge as a demo.

I brought in 50 loaded 223 rounds, long story short,my ammo was all over the place. We sorted into groups of out at .007-.008,, .003-.004, and I actually had 5 at .001.

I immediately went to the range and fired these at 200 at the same target in groups. The target showed the 7-8 in a neat 4" circle,, the 3-4 came in at 2 1/2" and the 5 that I had that where good came in at a sweet 1",, sub moa!!

I bought the gauge,, and began working on my bench techniques to control runout.

I gave the shop a copy of the target and I have it around here someplace, but they still use it as an example for folks when the question concentricity.

 

[zap]

necchi,
outstanding example !!
Thank you,
Lee