Fixing bullet runout?

drewman

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I've been reading alot about bullet runout and the gauges to measure it. But, what other ways beside turning the case next are there to fix it? And how much does the type of resizing you use help? /ubbthreads/images/graemlins/confused.gif
 
Runout is the amount the bullet is off axis in a case.I dont use the high quality brass (yet) so the only time I measure it is with a resized case thats been fired once.Once you have fired a case in your gun its as straight for that chamber as its ever going to be.Usually the procedure to size the case is the biggest cause of runout.I can only tell you whats worked for me,there are other ways with different dies.Ive given up on conventional dies with expanders and use the redding comp neck die set.Im not saying this is the route you should go,but it works for me.All I can say is a repeat from above.Your fired case is as straight as its ever going to be,so if you have runout issues,more than likely it has to do with your sizing procedure.
 
This is a simple question lots of possible answers and several little gremlins to chase down in the handloading process. Read Glen Zediker's, Handloading for Competition.
 
737,

I used to have runout issues with my loads, but with the help of Kirby (Fiftydriver) I have pretty much eliminated it.

First, you need to get a concentricity guage. Mine is from Sinclair, about $100. There are others out there some are less some are more.

Use the guage to measure your case necks and the bullets on loaded rounds. .001 or less is great, .002 is OK, .003 is very marginal and anything above that is not good.

A few months ago when started measuring runout I found that most of my loads had .005 to .007 which is terrible.

In order to cure the problem I took several steps. Remove the expander ball from your resizing die. The expander will stretch the case as it pulls through and will almost always cause runout.

Make sure you lube your cases well. I use imperial sizing die wax.

When resizing cases I use about 20 strokes of the press. I lower the handle until I start to feel pressure on the case then raise it back up and rotate the case about a 1/4 turn. I repeat this step until I am making a full stroke, usually about 10 to 12 strokes. Then I finish with 10 or so full strokes continuing to rotate the case each stroke.

I repeat the same process when seating bullets. Take care when you are starting to seat the bullet, just bump it and rotate the case 1/4 turn. Do this for several strokes untill the bullet is well into the neck then go ahead seat it, then do several more strokes, rotates.

There may be some who will say this is over kill or does not work that well, but I have proven it to myself over and over again. Using this technique I seldom see runout over .001 and most of my loads don't even make the needle move on my guage enough to see it wiggle. If I skip this and just size and seat in one stroke like I used to it is right back to .005 or more. If I try to shortcut the process with less care or fewer strokes, rotates then runout goes up to .002 or .003. Bottom line.......this works for me and if you do it carefully it will work for you.

Once you get the hang of it, it really does not take that much time either.

A set of competition dies will also help and with those you should be able to get runout down to well under .001.
 
[ QUOTE ]
In order to cure the problem I took several steps. Remove the expander ball from your resizing die. The expander will stretch the case as it pulls through and will almost always cause runout.

Make sure you lube your cases well. I use imperial sizing die wax.


[/ QUOTE ]

That is by far some of the best advice in this post.

My technique involves using a tight neck chamber. I dont get any neck expansion. All I do is run my cases through a body die and then neck size them. The less brass you compress, the less runout you will have. Scince I only neck size .002" of brass, I dont get any runout. With the tight neck chamber, if you have any run out, you will feel the neck hitting the chamber. Obviously, I dont use an expander ball. The deal here is very complicated, but for me, thats what works.

In part, the same can work for your. Neck size only what you have to after running your cases through a body die without the use of an expanderball.
 
Wow Good Stuff

Thanks for the great ideas. I have been using just a neck sizer after fire forming my brass. I know I need to invest in a gauge. But I do have some questions?

Are you taking the expander ball out of a regular fl sizer/decapper or are you taking it out of a comp die. I was thinking of getting into the reddington S-type but not sure if I need to at this point. IF you are just taking out the expander ball on the reg. die than I can go that way till I save up a little more cash.

The next question if you take the expander ball out do you have to get a decapper die to take out the primer. I might be missing something thats why I ask.


Drew /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif
 
You can take the expander/decapper out of a regular FL die. In order to decap, you can get a decapper die or use the expander/decapper from a smaller caliber die.

You will just have to experiment and try this. You may have trouble because of too much neck tension since you are not expanding the neck back out to the size of the expander ball. Make sure you chamfer the inside of the case mouth real well and use boattail bullets. If there is too much neck tension you will feel with your press and that can cause runout as well.

If the necks are too tight you can turn the necks to thin them down, or get a comp type die with neck sizing collets.

I have used both types of dies with the process I described previously. The standard FL die works fine for me, but I am loading for a rifle with a tight neck and I turn the necks on my brass.

A little experimentation on your part is in order, but hey, thats the fun part /ubbthreads/images/graemlins/smile.gif
 
Drew, most bushing style neck dies and comp dies (that I know of anyway) dont use an expander.The amount of resizing or bullet tension is set with different size bushings.Conventional dies use an expander because the neck is sized down much farther than it has to be.
 
Just some aditions to the good advice alreay given

While you wait for the bushing style dies and if neck tension is too high if you do not use the expander, deprime in a depriming die and loosen the expander nut a bit so that when you pull the case down the expander can adjust a little to the case axis.

You can also put an o ring in the base of the die and try with slight turns until you get the lowest run out.
 
There is one tool called the Bersin tool which "fixes" bullet runout with loaded ammo.
I have one and have used with success to date.
At the same time realize there is no such thing as a free lunch. When fixing the runout you will change the neck tension somewhat. I can use any 308 class case on one side and then the 284 Win family on the other.
It both measures and corrects runout.
It is expensive but, I like it.
Best way to stay ahead of the punch is to follow good loading protocol as has been mentioned above and in other posts.
Even then you will still have runout, then you seperate the bad ones for fouling/sighters and rock shooting.
I like the Bersin, but I'm not sure if many use it.
 
[ QUOTE ]
XP,
I do believe that the Bersin Tool fixes bullet "cant" not run out.
Run out can only be fixed by ensuring that the bore of neck and the case body diameter are on the same axis.

Ian.

[/ QUOTE ]

I disagree to some extent. Run out can be brought on by other means even if your brass is "perfect". Loading techniques, seating dies, etc. can all contribute to excessive run-out.

Also, I've never heard anyone refer to a misaligned bullet as being canted but, not having run-out. Run-out simply means the central axis of the bullet is misaligned w/ the central axis of the case and creating a loaded round that is not concentric.

These off centered rounds can be straightened by means other than a Bersin tool if you don't desire to go that route. A simple hole of the proper size drilled into a hardwood block works fine. A slight amount of pressure on the case while the bullet is inserted into this hole can straighten the round to an acceptable level. Notice I said slight pressure, if you are too rough w/ them you can effect neck tension greatly.

Good Luck

Reloader
 
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