Where benchrest guys measure bullet runout?

[DngBat7]

Just picked up a 21 century concentricity gauge tool. But I don’t actually know where to place the pointer on the bullet. Near the top, ogive, or where it enters the neck case?? What do the benchresters do?? Where do you guys place the pointer of the gauge?

 

[LA50SHOOTER]

Just picked up a 21 century concentricity gauge tool. But I don’t actually know where to place the pointer on the bullet. Near the top, ogive, or where it enters the neck case?? What do the benchresters do?? Where do you guys place the pointer of the gauge?

I measure on both the ogive and on the untampered bearing surface about midway between where the ogive starts and the case mouth. - Another thing that I do is check some fired cases that are wiped clean (not tumbled) to see that my chamber(s) are straight, I check in several places - its one of the first things I do after a day at the range with a new barrel. - once you know you're working with straight brass then you can use this as a method to check your dies & the reloading process.

 

[Dusty Stevens]

check in every spot.

 

[Chuckhunter]

I have always measured mine just ahead of where the ogive starts to bend away from the bearing area. I always check my cases after they have been turned, fireformed a couple of times and then cleaned to make sure I'm working with straight cases to begin with.

 

[DngBat7]

check in every spot.

The problem I’m having is what is 2/1000 by the neck is 7/1000 at the top. So when guys on the forum say “I get 1-2000th runout” at what point are they talking?

 

[DngBat7]

I have always measured mine just ahead of where the ogive starts to bend away from the bearing area. I always check my cases after they have been turned, fireformed a couple of times and then cleaned to make sure I'm working with straight cases to begin with.

I will try that

 

[DngBat7]

Actually now that I am running my hand loads on the 21 century, I can physically see the tip of the bullet wobbleing up and down as I spin it. I think I want to puke . Just opened a can of worms. So now what? I am using Forster ultra millimeter seating die with shoulder neck bump gauge? How do I get ride of some of the runout? It’s HORRIBLE!

 

[Uncle Ed]

What make and type sizing die are you using, full length, neck size, bushing, no bushing?

 

[Dusty Stevens]

How did they look on target? Welcome to the world of custom dies, future owner

 

[Falfan2017]

Is this brass you've already fired at least a couple times? Have you measured the concentricity of the neck of the brass before and after sizing? Are you using an expander ball on your sizing die?

 

[DngBat7]

What make and type sizing die are you using, full length, neck size, bushing, no bushing?

Forster shoulder bushing bump die, and Forster seater

 

[DngBat7]

Is this brass you've already fired at least a couple times? Have you measured the concentricity of the neck of the brass before and after sizing? Are you using an expander ball on your sizing die?

Fired once. Did not measure before. Just got the gauge and am using for the first time. So I’m a virgin concentricityist

 

[DngBat7]

How did they look on target? Welcome to the world of custom dies, future owner

Here goes more money...... crap

 

[#40Fan]

If you have some unloaded rounds, try seating a bullet half way, spin the case and seat the rest of the way.

Also, make sure the tip of the bullet isn't bottoming out in the seating stem.

 

[Chuckhunter]

Dan there are several things that can cause runout. From uneven Nk wall thickness to the expander ball (if you're using one) dragging through your case neck as it is backed out of the die pulling the case out of line. Let us know your procedure and perhaps we can help. In a hunting round I don't worry about .003 or less and for my 1000yd, match ammo My criteria is much tighter @ .0005 or less. Do you nk turn your brass & do you use an expander ball in your sizing die?

 

[DngBat7]

Dan there are several things that can cause runout. From uneven Nk wall thickness to the expander ball (if you're using one) dragging through your case neck as it is backed out of the die pulling the case out of line. Let us know your procedure and perhaps we can help. In a hunting round I don't worry about .003 or less and for my 1000yd, match ammo My criteria is much tighter @ .0005 or less. Do you nk turn your brass & do you use an expander ball in your sizing die?

Dan there are several things that can cause runout. From uneven Nk wall thickness to the expander ball (if you're using one) dragging through your case neck as it is backed out of the die pulling the case out of line. Let us know your procedure and perhaps we can help. In a hunting round I don't worry about .003 or less and for my 1000yd, match ammo My criteria is much tighter @ .0005 or less. Do you nk turn your brass & do you use an expander ball in your sizing die?

I included a pic. I am using this as purchased. I am sure I will have to buy something, so just lay it on me

 

[Uncle Ed]

Forster shoulder bushing bump die, and Forster seater

Neck sizing bushing dies will produce more runout than a non-bushing full length die.
1. A neck sizing die does not support the case body and hold it in alignment with the neck.
2. If reducing the neck diameter .004 or more a bushing die can induce neck runout.
3. Bushing dies work best with neck turned brass in custom tight neck chambers. Meaning the more you have to reduce the neck diameter during sizing the more neck runout you can have.

Bottom line I have many .223 dies and the Forster bushing bump die had more runout than any other die. That being said the standard Forster full length sizing die produced the least amount of neck runout. And there was no improvement with removing the expander and then using a expander die.

 

[DngBat7]

Are they’re any good reloading videos maybe on you tube for reloading for benchrest start to finish? If not that makes a good title for one of you to produce one.

 

[Uncle Ed]

I included a pic. I am using this as purchased. I am sure I will have to buy something, so just lay it on me

If your rifle has a standard off the shelf factory SAAMI chamber you are reducing the neck diameter more than .004.

The bushing floats and can move from side to side and even tilt when sizing the neck.

Redding states in their bushing FAQ if you do not turn your necks and have more than .002 neck thickness variation to use their expander. The FAQ also states if reducing the neck diameter .004 or more to reduce the neck in two separate steps.

And again I get the least case neck runout during sizing with the Forster full length benchrest die using their high mounted floating expander. And if the necks are turned to just remove the high spots with less than 50% of the neck turned I can get .001 neck runout.

 

[Murray Brook]

Dan depending on how little run-out you want ,I find, the cheapest way to greatly reduce run-out in a saami chamber is to use a Redding body die to size the case and bump your shoulder and a Lee collet die to size the neck. Works great for me. Low cost as well.