Bullet runout or concentricity

[rockydoc]

No runout at all would be ideal. Wouldn't perfection be great!

I am not sure what the least acceptable runout should be. I have only recently purchased a gauge and the runout I got on my latest 308 Win loads ran from a low of .002"(4 out of 15) to .007-.008 for the rest. I think that is not good.

I am using Lee dies. I think that a better bullet seating die would go a long way toward correcting my runout problem. If so, what bullet seating die would you recommend ?

I am using Winchester Match Brass.

 

[marchboom]

I like, and use, Forster seating dies. But I think the inline dies (Wilson, etc) will give the least runout.

 

[L.Sherm]

No runout at all would be ideal. Wouldn't perfection be great!

I am not sure what the least acceptable runout should be. I have only recently purchased a gauge and the runout I got on my latest 308 Win loads ran from a low of .002"(4 out of 15) to .007-.008 for the rest. I think that is not good.

I am using Lee dies. I think that a better bullet seating die would go a long way toward correcting my runout problem. If so, what bullet seating die would you recommend ?

I am using Winchester Match Brass.

Have you shot those .007- .008 and see how they shot compared to the .002, you maybe surprised.

 

[Bill Norris]

No runout at all would be ideal. Wouldn't perfection be great!

I am not sure what the least acceptable runout should be. I have only recently purchased a gauge and the runout I got on my latest 308 Win loads ran from a low of .002"(4 out of 15) to .007-.008 for the rest. I think that is not good.

I am using Lee dies. I think that a better bullet seating die would go a long way toward correcting my runout problem. If so, what bullet seating die would you recommend ?

I am using Winchester Match Brass.

Some test have been conducted by top shooters with up to .015 runout and no affect on group size was determined.

 

[jobhopper66]

I have a concentricity gauge and it has helped me refine my reloading program but as Bill said many excellent shooters have proven that in the end you may be " looking for a difference that really makes no difference". The target will always have the final word in this argument.

 

[Bill Norris]

I have a concentricity gauge and it has help me refine my reloading program but as Bill said many excellent shooters have proven that in the end you may be " looking for a difference that really makes no difference". The target will always have the final word in this argument.

Yea, the gauge comes in handy for setting up new dies but that's about all I ever use mine for anymore.

 

[HTSmith]

How is it shooting? Not sure run out should be at the top of your list.

 

[K22]

Never found run out to be a defining accuracy factor, at least at the level I am shooting at.

 

[6BRA]

Your runout more than likely isn't your seater. More than likely your sizing process. Unturned brass could add .0015 to your runout alone on case neck.

 

[Ranger188]

@rockydoc, most have thrown their concentricity gauges out.
Work on your reloading process. Good dies and components will produce good straight ammo.
Most beginners buy them also, they read you have to have perfectly straight ammo.
How does the rounds shoot? Let that be your guide.

 

[vmaxpro]

I havent been on here in forever, but I saw this and felt the need to respond. I used a 6x47L to test case runout results. X caliber barrel 8 twist and 87gr vmax. This chamber has a very tight freebore diameter. Tight enough to where if you use a hornady oal gage, it takes a little pressure. Using redding dies, I would get between .0005 to .0015 as is. I would then tweak them to .012-.015 ( measured close to the tip). They shot just as good, no change. Im guessing the tight freebore true’s it up for you. Factory barrels could be a different story however. Consistent neck tension had a much larger affect on accuracy from what Ive found over the years. Good annealing and lube the id of the neck will go along way for you.

 

[L.Sherm]

Your runout more than likely isn't your seater. More than likely your sizing process. Unturned brass could add .0015 to your runout alone on case neck.

This is what I dont get, some stress over runout but then run crap brass and dont even turn necks.
Run good brass, dies set them up properly and the runout is taken care of.

 

[BoydAllen]

Generally speaking the bullet will follow the case neck. If you want straighter ammunition you need to do what is needed to make straighter sized brass. One of the best ways to do this is to use a Redding body die in conjunction with a Lee collet die, if you are working with unturned case necks. If your budget limits your die options then remove your expander and carefully, with lube, expand with a die and mandrel. Using straight brass, one seater may produce straighter results than another. The common solution in benchrest is to seat with a Wilson die or something similar, custom made, but no seater will fix problems that stem from the brass being crooked.

 

[Kevin1990]

For what it's worth, I asked a question similar to this about run out a few months back and got pretty much the same answers you're getting. I was shooting a 30BR at 1-200 yards. I took my reloads that had .001-.002 and ones that had .003-.006. I shot 5x5 with both sets of reloads and saw no difference in group sizes. That being said, I still dont want runout.

I found that the runout in my situation was coming from the press itself. Just something to maybe think about. For my 6br I FL size without the expander ball and then get the proper neck tension with a mandrel die.

 

[X Count]

Some test have been conducted by top shooters with up to .015 runout and no affect on group size was determined.

I've tested up to half of that variation with no real advantage on an F class target.

What I find so hard to wrap my head around is how a chamber and throat need to be withing 1 TENthouthanths yet we can feed it ammo that is miss aligned 100x that tolerance and it doesn't cause major issues.

 

[Bill Norris]

I've tested up to half of that variation with no real advantage on an F class target.

What I find so hard to wrap my head around is how a chamber and throat need to be withing 1 TENthouthanths yet we can feed it ammo that is miss aligned 100x that tolerance and it doesn't cause major issues.

I agree with Alex Wheeler when he ask how crooked can the round remain when placed into a chamber as you described?

 

[JMayo]

Check really close to the case mouth when checking. The father out the more it'll show. On the 140gr 6.5, such a long bullet, it's magnified greatly out at the ojive.imo.

My 6.5x47 some are . 005, some are .001.
I like using the gage to help steer me in my process.
Ppl tell me i don't need it. Umph !
"They" may not. .....my toys, my game my way.

Play on brother !

 

[urbanrifleman]

Buy better brass. Then forget about it.

 

[urbanrifleman]

I've tested up to half of that variation with no real advantage on an F class target.

What I find so hard to wrap my head around is how a chamber and throat need to be withing 1 TENthouthanths yet we can feed it ammo that is miss aligned 100x that tolerance and it doesn't cause major issues.

Steel is hard.

Brass is soft.

Some people have it in their minds that barrels are made from frozen butter and ammunition is made from titanium.

 

[6BRA]

Even Lapua brass can be twisted if run through crap resizing process.