Why excessive runout on some rounds?

[Rich Coyle]

When my cases come out of the die after sizing normally there is .000" runout on the neck. The tips of the bullets runout as much as .015". Lately I have been seating and turning the case so the bullet gets another chance to seat straight. It has been helping.

 

[nksmfamjp]

What are you using to measure run out?

Also, I find a properly measured 0.006" to be good.

 

[buckbrush]

I'll likely get crucified for this, but I used to spend hours trying to correct run out in multiple rifles until I verified on paper and at distance if there was any difference in performance. If there was a difference, it was negligible with all of the rifles I verified. This was with up to 0.012" of runout on my gauge, which was as bad as I measured.

My advice: put the gauge away and spend your extra time reading wind.

 

[katakenm]

Ok. I'll be the dummy here who has to ask: what exactly is "runout"?

Ok... "runout", in my opinion, is when you shoot a perfect group, your last shot you get a flyer, and hence the term "run out", you have to "run out and hurry and change your target so nobody sees that flyer!

All joking aside, the guys explained exactly and I just had to add a little humor!

Shoot straight brothers!

 

[Boatmanxxx]

Separate the rounds that are outa the norm on run out. go to the range and shoot the rounds that are in "spec" and the ones that are not. See what the difference is and report back.

 

[TheLongRanger83702]

Using a Hornady single stage or a Dillon 550 progressive, with a Forster micrometer seating die. Making me crazy. I'll get most loaded rounds at .003 or less runout, but will get occasional at double that or more. What gives? Pretty deliberate about my loading process and careful, so don't understand what, if anything, I'm doing wrong. Any insight appreciated.

You're using crappy brass. @ 7 years ago I reloaded 1700 - .308Win rounds for my Wilson Combat Super Sniper AR-10. NONE of the Nosler brass reloaded rounds went over .0005" for @ .25" MOA. @ 100 yds. I think they manufacture incredible brass.

 

[Jeffrey Van Zandt]

Using a Hornady single stage or a Dillon 550 progressive, with a Forster micrometer seating die. Making me crazy. I'll get most loaded rounds at .003 or less runout, but will get occasional at double that or more. What gives? Pretty deliberate about my loading process and careful, so don't understand what, if anything, I'm doing wrong. Any insight appreciated.

are you match prepping your brass, doing all necks the same say 12 tho. weighing and then sorting them, same type of brass and annealing the necks each time. any brass over 1 tho out I plink with most shot well but for game I want one nothing over 1 tho.

 

[Gater]

I use an RCBS summit press with a Forster micro seating die either Norma or Lapua brass they come out within .01-.02. I used to seat the bullet about half way turn the case and finish seating doing this I could never get a consistent CBTO I stopped the turn stayed with a smooth full stroke now my CBTO are within.01 and very very little runout.

 

[RidgeTop]

My guess is each case is not completely up against the shell holder - may have backed out a little. Rotating 180deg is a sure way to reduce possibility of runout and good practice.

 

[lancetkenyon]

What bullet? That can make a HUGE difference.

 

[pdog shooter]

I finally am able to load all my 6.5 creedmoor with <oo1 runout. Take your pick but I feel it was a combination. Replaced press with forster a frame, stopped using bushing dies, anneal after each use, neck turning to uniform thick, mandrel expand, clean inside of neck to like new, rotate brass on resize and mandrel and setting. Not in that order and I'm sure I forgot something but everything seemed to help. 30-06 still has plenty of runout but I'm not trying to hit targets 1000 yards away.

Oh yea, lapua brass helped also

 

[emp1953]

Using a Hornady single stage or a Dillon 550 progressive, with a Forster micrometer seating die. Making me crazy. I'll get most loaded rounds at .003 or less runout, but will get occasional at double that or more. What gives? Pretty deliberate about my loading process and careful, so don't understand what, if anything, I'm doing wrong. Any insight appreciated.

I suffered through a smilar problem using a RCBS rock chucker single stage press. After much hair pulling I found that my .243's had no runout problem but my .270win did. I was changing out the shell holder everytime I changed die caliber. I used the shell holder a #3 for the .243 with the .270win dies and lost my runout problems. The #3 that I had been using for the .270's was ancient, used since 1969. Had worn some and it would suffer from a grain or two of powder getting on the case head bearing surface. The newer #3 would not let the shell into the shell holder. The older one would allow it, thus causing a "cant" in the case and giving me a rounout problem. Sometimes it's just the little things.

 

[VenatusDominus]

If you are using a bushing type die, switching to the SAC neck bushings will all but eliminate runout.

 

[nwmnbowhunter]

If your cbto is also varying then your forster micrometer bullet seating stem is messed up.

Forster stems are extremely fragile.

Get rid of that die and get a redding micrometer seater if that's the case.