Bullet Run-out
- Thread starter jfarrell
- Start date
Bullets with more run-out than I'm willing to accept get put in a "practice loads" pile. Then I should them and often find they're only a hair less accurate than my zero-run-out loads. Don't ask me why my '30-06 sporter can stay inside 4" at 300 meters when shooting ammo with 7 thousandths of run-out. The day that happened, I just shook my head and carried on.
The best solution is to avoid run-out in the first place. While everyone has their own approach to this, I have to say that my decision to switch out all my conventional seating dies for Forster Benchress Ultra Seaters (collet seating dies that are essentially the same thing as the Reddings) was money well spent, as they produce considerably less run-out.
The ammunition i have been loading seems to average around .003"
Or less runout. This ammo Is Used for longrange work (500-1000+ yards). With no ill effect.
Much more than that, say .005-.007"+, and you will start to See "patterns", Rather than groups.
With that being said, at most hunting distances (300 or less) there will be minimal dispersion. If you are a precision minded shooter, thats still too much.
Less is better in this particular instance.
Or less runout. This ammo Is Used for longrange work (500-1000+ yards). With no ill effect.
Much more than that, say .005-.007"+, and you will start to See "patterns", Rather than groups.
With that being said, at most hunting distances (300 or less) there will be minimal dispersion. If you are a precision minded shooter, thats still too much.
Less is better in this particular instance.
One method that works, if your dies aren't crooked to the shell head holder, is to turn the loaded cartridge 1/4 turn in the shell head holder and run it into the seating die again.
I have found more than one set of crooked dies. I have also found a couple of different types of presses that have been threaded on a very slight angle or slightly off centre.
In the case of the RCBS Rock Chucker, RCBS replace it without question, even verified it should never have been on the market. They paid for shipping both ways and even threw in a set of 7x57 dies they used to check the replacement press. This was 20 years ago but I don't think they've change much with their customer relations.
If you have a set of dies or a press giving you concentricity issues, get in touch with the maker and it is more than likely they will replace it.
Equipment bearing their name, that doesn't do what's advertised, is bad for business.
Johnn Peterson
CGN Ultra frequent flyer
- Location
- Chemainus B.C.
I find if I don't happen to get the correct seater plug to match up with the bullet I happen to be using, I sometimes do get a varying amount of run-out. This something I've started playing with as part of my reloading, striving for a 'touch' better accuracy by eliminating another of the little inconsistencies we run into. The unit pictured below is what I decided on to use, a Lock-N-Load Concentricity Tool by Hornady.
It works well.
I've never really noticed much if any difference on paper with some of the 0.003" - 0.005" odd bit of run-out but especially for paper punching, I've started straightening. That's changed as being retired, I have the time so I now check & straighten, if required, virtually all my bottle necked rifle reloads.One less 'excuse' I have to blame on the odd flyer. Actually, with the appropriate or closest matching seater plug fot the bullet used, very rarely is the run-out more than 0.001" or 0.002"
In an effort to 'justify' this additional step and to try and determine how much difference it really made, I purposefully off the concentricity by 0.010" and on the brass, marked which direction the offset was. When I loaded the rounds in the chamber, I placed the next offset off at 90 degrees to the previous. I shot four shots at each target and shot two targets with those offset loads. Then, shot two more targets, four shots at each with straight rounds. There was a noticeable difference in group size between the two different ammo batches. I'll have to do it again. I was going to post the results but
da**ed if I know where those targets are.
It works well.
I've never really noticed much if any difference on paper with some of the 0.003" - 0.005" odd bit of run-out but especially for paper punching, I've started straightening. That's changed as being retired, I have the time so I now check & straighten, if required, virtually all my bottle necked rifle reloads.
One less 'excuse' I have to blame on the odd flyer. Actually, with the appropriate or closest matching seater plug fot the bullet used, very rarely is the run-out more than 0.001" or 0.002" In an effort to 'justify' this additional step and to try and determine how much difference it really made, I purposefully off the concentricity by 0.010" and on the brass, marked which direction the offset was. When I loaded the rounds in the chamber, I placed the next offset off at 90 degrees to the previous. I shot four shots at each target and shot two targets with those offset loads. Then, shot two more targets, four shots at each with straight rounds. There was a noticeable difference in group size between the two different ammo batches. I'll have to do it again. I was going to post the results but
da**ed if I know where those targets are.
More ammunition is reloaded with excess run out for one very simple reason, the decaping pin/expander button is locked down off center in the die. There are two ways to center the decapping rod for less run out.
1. Loosen the lock nut on the decapping rod, and with a case in the shell holder lower the ram until the expander button just enters the neck of the case and then tighten the lock nut on the decapping rod. This will center the rod and decrease bullet runout.
2. Place a small o-ring under the decapping rod lock nut, and tighten the nut lightly by hand. This will let the decapping rod "float" and be self centering.
NOTE: If you have any dents, dings, or imperfections in the extractor groove of the cartridge case, the shell holder might hold the case crooked and off center on the down stroke and pull the neck off center. Also if you are neck sizing only the Lee collet die can hold your case necks to under .001 runout and this is cheap accuracy.
New Brass Preparation
by Germán A. Salazar
http://riflemansjournal.########.com/2010/12/basics-new-brass-preparation.html
Indexing Cases
by Germán A. Salazar
http://riflemansjournal.########.com/2010/11/reloading-indexing-cases.html
O-Rings on Dies May Reduce Run-Out
http://www.accurateshooter.com/technical-articles/reloading/o-rings-on-dies-may-reduce-run-out/
How to Load More Concentric Ammo
http://www.accurateshooter.com/technical-articles/reloading/how-to-load-more-concentric-ammo/
1. Loosen the lock nut on the decapping rod, and with a case in the shell holder lower the ram until the expander button just enters the neck of the case and then tighten the lock nut on the decapping rod. This will center the rod and decrease bullet runout.
2. Place a small o-ring under the decapping rod lock nut, and tighten the nut lightly by hand. This will let the decapping rod "float" and be self centering.
NOTE: If you have any dents, dings, or imperfections in the extractor groove of the cartridge case, the shell holder might hold the case crooked and off center on the down stroke and pull the neck off center. Also if you are neck sizing only the Lee collet die can hold your case necks to under .001 runout and this is cheap accuracy.
New Brass Preparation
by Germán A. Salazar
http://riflemansjournal.########.com/2010/12/basics-new-brass-preparation.html
Indexing Cases
by Germán A. Salazar
http://riflemansjournal.########.com/2010/11/reloading-indexing-cases.html
O-Rings on Dies May Reduce Run-Out
http://www.accurateshooter.com/technical-articles/reloading/o-rings-on-dies-may-reduce-run-out/
How to Load More Concentric Ammo
http://www.accurateshooter.com/technical-articles/reloading/how-to-load-more-concentric-ammo/
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