Causes of runout

[Dean]

What do you think is the SINGLE biggest contibuter to runout.

a)Dies
b)Press
c)Human error

Thanks,
Dean

 

[tightneck]

I'd say dies as well and the sizing die in particular most of the time.

 

[amamnn]

I used to be optomistic about my fellow man and blame the dies. I've since learned better--human error.

 

[Clarence]

I'll throw in the amount of neck tension will cause bad TIR too much and ya get it, no such thing as too little IMHO.
Also one needs to turn or rotate the round when seating.
Could be cases especially with the cheep stuff, BUT if one sizes the cheep stuff to only allow the bullet to touch the leade and the case head to touch the bolt then whom cares about the rest of the case.

Clarence

 

[JERRYHM]

Causes of runout
1. use of an expander ball
2. sizing die
3. seating die

Does anyone have a test method that proves runout is important?

 

[aJR]

Jerry,I have proven if only to me that at 3 thou of bullet runout at the point where i check each round that the one with the runout will leave the group "everytime"..I straighten each round just before each group,even on the barrel foulers..I use a tolerance of less than 1 thou on the record rounds evn though i have not been able to prove it is worth the extra effort..Pic of the tool i made to check they are in line..JR..Jeff Rogers

 

[Dean]

Thanks for the input.

I don't have a gauge to check my runout,yet)but when I roll the loaded round on a sheet of glass I can see some wobble.The reason I asked is because it doesn't happen on all of them...in fact only about 10% of my rounds have this problem.

Since I do everything the same every time I scratch my head and wonder where the runout is coming from.

I'm in the process of putting together some equipment to start loading for a 6br and I didn't know if I should go with Redding screw in dies or go with an arbor press and Wilson stainless hand dies.,Any advice in this matter would be helpfull).This won't be for competition so I don't see the need for custom dies.

Anyway,thanks again
Dean

 

[chino1969]

I've used both threaded and Wilson hand seating dies and the Wilson will consistently seat a straighter bullet. Some people claim to get .001 or less with a threaded competition seater but I'm not one of them and I have three made by different manufacturers. I
Chino69

 

[mysticplayer]

I have been testing my ammo at every stage since getting my Sinclair runout guage a year ago.

I have found that the sizing die is the number one place for creation of run out,assuming the case is true coming out of the chamber). Almost always, it was a sizing dies with a decapping rod.

Now was it during the sizing or expansion that the runout was created? That I have not tested but by playing with the expander rod to 'straighten' it, seems to reduce the problem.

Best I can set up these dies is 1 thou neck runout,turned necks) with the occasional 2 thou. Sometimes it is alot worse.

The best die I use is the Lee collet neck die. I have now covered the entire spectrum of cals with this die in a wide variety of cartridges. This die DOES NOT CREATE RUNOUT IF USED PROPERLY - at least none that I can measure.

All sizing done in a Lee Challenger press by the way so you know where my thoughts are about presses.

For seating, I have used Forster BR seaters, and reg seaters offered by Hornady, RCBS and Lee. Really don't see much runout created in this step, even when loading long VLD bullets so I don't bother getting fancy seating dies.

When I first got the runout guage, I found one of my more accurate shooting rifles had ammo with alot of runout,avg. 5 thou). Ironically, the best group it has ever shot at 200yds was with reject ammo that had runout from 5 thou to 8 thou,bad day at the loading bench). Go figure.

Does runout matter? I figure reducing or eliminating it can't hurt.

Jerry

 

[Allene]

Jeff Rogers
I like the looks of your run-out gage and am impressed in what appears to be the quality of it. I currently have about four different make run-out gages as I use them when I teach a class but that is almost the only time I use them once I have settled on equipment. What I would be interested in hearing about or learning your methods of straightening loaded ammo. I currently have one Bersin and one H&H. I do not change the set-up on the H&H and the Bersin has only to move the dial indicator in or out. I have seen Bruno's but did not buy one of his. I have not seen any other brands and am more curious than anything else.
Thanks in advance,
Allen Elliott

 

[aJR]

Allen,I am a long way from the hub of Long Range competition shooting,i live near the top of Australia and have had to come up with my own solutions for the most part ...I have been straighting the loaded round since 1997 because i have been unable to load "ALL" of the cartridges straight weither i use with 7/8x14 dies or the arbor style, no matter what i tried..U will notice i said "ALL", i find a bunch of guys saying that they checked the 1st 10 rounds, all within tolerance so they didn't bother with the rest.In my case the more i check the more i find with runout...A lot easier with a PPC case than a 300ACK,i might add...I tend to shoot the longer cartridges, my present set up will load 100 cartridges within about 2.8 thou,on average about 75 of those will be at .0012..I straighten "ALL" to less that 1 thou... To straighten the loaded cartridge without distroting the case and rendering the neck tension inconsistent it is necessary to run light neck tension .. I run a the minimum tension required to keep the bullet in place in the neck depending on the seating location..It just a simple matter of tapping on the shoulder in my guage to align the projectile...I shoot the record rounds to a less than 1 thou tolerance at every point on the loaded round that you might like to measure,i think it is the fine details that win matchs...JR..Jeff Rogers..Pic of my latest ConC guage that does the 3 checks all in one..

 

[Allene]

Jeff
Thank you and I concur with much of what you do and say. Again I am impressed with the quality of your equipment and methodology.
Allen Elliott