How much Runout is acceptable ?

[short range]

Hi Lhsmith, you are right about the .330 neck instead of bore, sometimes I use the wrong terms. Al did let me know that he turned the necks to exactly .001" The scope is a Leupold 36x Br, I'm using 34.4 gr of H4198, 10x 120 gr HPFT bullets on a .925 jacket, Lapua brass, O.A.L. 2.272", all of these components are what Al was using. I don't know what "jam or jump" mean.
camac did a good job of discribing my situation. Al gave me a lot of info about the rifle and shooting form, I'm sure that I forgot a lot of the info that he gave me that day, it was info over load at that point, but I'm glad he gave me all that help.
After much debate on this forum, several people suggested that I buy the Sinclair Concentricity Gauge. You are probably correct about the Harrells Die and the Wilson seating die. We just learn as we go.

 

[short range]

I will download the "windchart", The Sinclair gauge that I bought was $99.95, not $14, but it is what it is. I have made probably 10 or so trips to the range with my 30BR, first shooting the 72 loaded rounds that Al loaded, and several times with my reloads. I have only been shooting two rounds to dirty the barrel,and four- three shot groups each time that I go. I bought my front and rear rest used from a friend, I have a Caldwell front rest (I think it's The Rock BR), with Caldwell 3" front bag. and I'm not sure what rear bag that I have, but it looks like the " Poter Tor Model "with the bunny ears on page 67 of the Midway USA master catalog #33. If my test won't be accurate before I learn how to read flags, maybe I should wait and not not finish my test.

 

[alf]

Steve,

At this point, don't change a thing with your reloading process. I think you're focusing a little too hard on this runout thing, when in reality, your under .002. A little puff of wind negates a whole lot of perfection if you can't read it. You're shooting good enough groups to start working on your bench manners and flag reading skills. The biggest improvements will come from that now. Don't start chasing groups with equipment.

 

[necchi]

Don't start chasing groups with equipment.

Good words.
This is a great thread with lot's of good info, but the bottom line is most guns shoot better than most people.
Lot's of range time pays off,, alot. ;D

 

[short range]

Thanks alf, I did learn a lot with this thread, and for the most part, I got to cut my bullet runout in half. I will start focusing on the wind and bench shooting manners, although I have been concentrating on bench manners from the start. You gave me great info on that the day that I bought the rifle. I think shooting manners can effect group size as much or more that wind at short yardage. I will have to read up on judging wind with the flags, and download the chart. We have 5 to 15 mph west winds today, so I'll go to the range for a while today, and use the flags and see what happens. I didn't really think about it much, but when I shoot, I do wait to shoot in between gusts of wind, I guess that's just second nature to my now, but I don't normaly shoot rifles that I shoot for tight groups on real windy days. If it's real windy, I take my AR if I shoot, it has an EOTECH sight, I don't shoot very tight groups with that anyway.

 

[short range]

I did a search for "windchart" on this forum, but didn't find it. Where can I download it from ?

 

[short range]

I did go to the range today,sunny, 61 degress, 5 to 20 mph swirling winds at the range. the dominating wind was from right to left. I used the flags for the first time. I found them distracting, I guess it's like anything new, I'll get used to them. I shot four-five shot groups. The wind did open my groups up some. Here is my group sizes:

group #1 .258"
group #2 .250"
group #3 .435"
group #4 .232"

Group #3 I shot one round in a strong right to left wind to see haow it would effect the point of impact, it move the point of impact almost 1/4" to left of the other four rounds. I use the 1" orange stick on targets with the 1/2" ring and center dot on poster board (or poster paper) because that is what I have used for the last two years, It's just one thing that I wanted to keep as a constant facter with all the other changes.

 

[camac]

Excellent shooting for swirling winds from 5- 20 knots. Good work. Don't worry about the flier we all have them and can't read wind every time (I have a great deal of trouble with it). Have you run your projectile and velocity through a ballistics program to see how much wind effect you are getting from the wind? If you do, I think you will be even more please with your result.
Roughly speaking (without knowing your bullet , velocity, BC etc) you could expect the 30BR to move over 2 inches in 20 mph wind. or 0.1 inches for every mph. For those groups above in variable wind conditions you are reading the wind extremely well. Good stuff.

 

[whiskey08]

Im wondering why my redding seating die is putting .003 of runout on my rounds. The runout is almost exact from round to round so I dont think its differences in neck thickness. Now Im going to have to try a wilson seating die.

I tested my loads the other day, 4 shot groups (.308win off of a bipod) are around .32" to .35". They're bigger than id like but im banging 6inch and 9inch steel plates out to 750yds so Im thinking the runout isnt affecting it too much.

Overall i think im gonna be more concerned with why my die is causing runout than how much the runout is affecting accuracy.

 

[camac]

Whiskey, every factory die I have owned or seen didn't match the chamber. I end up "accurising" them to suit the chamber or align better. Some of the redding dies are a very simple process. Before spending money (proabably unnecessarily) on the Wilson which may not necessarily fix your runout -which seating die are you using? and also is your neck showing any runout before seating but after sizing?

 

[whiskey08]

at the very most, a few cases will have less than .001 of runout after neck sizing. During seating with a redding competition seater is where the runout appears. Id appreciate any tips on tuning my dies.

 

[BoydAllen]

Use a VLD chamfer and shove the end of the neck into a wad of 0000 and give it a couple of turns to further smooth things. Some time ago there was an article in Precision Shooting that reported an improvement in runout with the longer chamfer. Also, you will get more consistent seating depth if the die body just kisses the shell holder. It was previously mentioned that seating the bullet half way and then turning the round 180 degrees and finishing cut his runout in half.

 

[camac]

As Boyd said plus:
The redding cometition seater has fantastic tolerances in the bullet holding bore but the issue comes in that the shell holding collet is cut to accomodate the largest of possible chambers within saami specs (they have no choice so is no fault of redding). What you find is a 2-4 thou clearance on most chamber sizes and can be more.
Although the bullet is held well, the top of the shell and neck can be out of alignment as it has more play. What you need to accomplish is have the neck centralised in the collet.
Fix # 1: One easy solution is to grind the collett back at base of shell so shell holder doesn't push collett up but rather cone of shoulder of shell does . This helps the cone centralise neck in the body. A simple fix that can help a lot. This is not a critical dimension so can be done in drill or lathe. It is normally close so might only have to take a little off. Then just concentrate on base of shell being exactly the same iin holder as well. Maybe the 180 double seat might help...
Fix# 2: A little more fiddly but can do an even better job of aligning than step one above. Go to auto spares shop and buy some shim material (comes in packs with several thicknesses and very cheap) and cut a thin band of shim to place all the way around in collet (collar of shim material). You will need one at base and one near shoulder. Try 2 or 3 thou material. The shim can move so keep an eye on it. If you do a few shells like this and find dramatic improvement you may want to explore # 3 below. Just watch for shim material moving up into neck and shoulder as can cause longer seating.
Fix # 3: This is the best. If you still have reamer for your rifle or know the gunsmith that did it for you - contact redding and get a collett blank. You can then send it off to smith to cut your exact chamber into die. I actually made one from scratch using my chamber reamer and barrel stub and 6mm reamer for bullet bore. Contrary to common opinion you don't need an undersize reamer to do the seating dies - only the FL sizing ones. This approach along with a custom FL die can give almost perfect results all the time.
Cam

ps 1 thou neck runout can easily cause 3 thou at ogive so look at that too.

 

[whiskey08]

great thread, and great info, Ill try these ideas and report back. Ill also see about a blank die from redding and have my gunsmith ream it. thanks for the help.

 

[short range]

Thanks cam, I have not run my projectile and velocity threw a ballistics program, I don't know what the velocity is, I think Al said it was something like 2,950 feet per second, I'll have to check with him. I don't have a cronograph. That's good to know about the aprox. .01 inches per mph, I assume that's at 100 yards.

 

[short range]

Hi whiskey08, As Boyd and cam mentioned, the first thing I would try to fix your seating die runout is to mark your brass with a sharpie, and seat the bullet 1/2 way, then turn the brass 180 degrees and seat the bullet the rest of the way, then check your runout. It cut the runout in my rounds in 1/2. If that works for you, that seems to be the easiest fix. If it doesn't help, then try the other methods.

 

[camac]

Yes at 100 yards 0.1 inches per 1mph (roughly). AS per everyones comments that runout becomes a little insignificant if you can't read flags or shoot in the "same wind".
It sounds more daunting than it actually is though. Read a couple of the articles on reading the wind. Before starting your groups you should fire a few sighters in the different wind conditions just to get a feel for how far it will move it at your range. Sometimes the wind is 15-20 knots but only having a few knot effect on your bullet (due to orientation, trees, groundcover etc). It is worth concentrating on shooting in the "same wind" not necessarily a zero wind.

For some idea Here is a 30BR table for 115gr Bergers doing 2950 fps (from JBM ballisics) and a 10 mph wind (wind effect is linear so can divide by 10 for every 1 mph)

Calculated Table
Range Drop Drop Windage Windage Velocity
(yd) (in) (MOA) (in) (MOA) (ft/s)
0 -1.5 *** 0 *** 2961
50 -0.2 -0.4 0.3 0.5 2798.5
100 0 0 1 1 2641.9
200 -3.5 -1.7 4.4 2.1 2344.3
300 -13.4 -4.3 10.6 3.4 2066.4

 

[camac]

Another one to watch for on the bags is cant of rifle. A couple of degree cant will move you about 0.1 inches as well.

 

[whiskey08]

Short Range,

Ive tried rotating case 1/2 turns, 1/4 turns and the runout is still .003 almost exact on every case. so that leads me to believe its not loose componets, but something is off that much in my seating die??? there's some great posts for great ideas im gonna try also. thks

 

[camac]

Thinking about it - the 180 twist won't work so well in redding comp seating dies. If the bullet is 3 thou runout to one side but you have "play" of 6 thou in the chamber (3 on each side - very common), rotating will still have the play on the other side so will not contact and bring back in line.