Would someone be kind enough to explain " bullet runout" to me ...in laymans terms please..

How do I measure it???..sakofan...

Bullet round out is where your bullet is centered in your cartridge case so when you chamber your round in your rifle the bullet is in the center of your bore. If your case isn't in the true center to the chamber and your bullet is off center it can cause problems with your accuracy, the worse the round out is the less accuracy you will have. So case preparations prior to reload is very important. Good Luck

I full neck size every case, trim, deburr, what else can I do to eliminate runout???..sakofan...
Thanks!!

Sakofan, "pray"
Runout can be caused by a off center chamber or expander ball, bad sizeing die, improper bullet seating, and will show some runout unless neck turned due to uneven case wall thickness.
Your best bet is to get a runout guage and eliminate the causes one at a time as you find them. RCBS, Sinclar and I believe a few others manufacture them.
That or forget you ever heard of runout and keep your hair

Sakofan, controlling run out is very important. You won't know what you are doing unless you get a gage. RCBS and Sinclair make good ones at a reasonable price. They also come with instructions. Until then run your catridges into your sizing die several times rotating the case about a quarter turn in the shellholder each time. It helps but without the gage you can't tell how much. Even if your cases are concentric you can mess things up during bulet seating. Using match dies from Bonanza, RCBS, or Redding will help. If you are doing any long range or varmint shooting controlling run out is vital. Good luck.

How much runout is good, and how much effect will be noticed in accuracy?. I have the RCBS gauge and in the instructions it says less then .005 is ok for hunting. I tested a bunch of my loaded 6.5x55 rounds and most were around 0.005, i had a few with 0.001 and 0.002 though. Some of my old 30/06 wasn't as good though, runout on a few was 0.015, its just for plinking anyway.

Brett

Have quit using a a expander ball on the depriming and have gotten less round out. You could get a Forster case trimmer with the outside neck turner. Even with out a proper guage you could make one very light cut on the case neck and you would be able to see that the case is out of round and then after doing it to all your case make a second cut which should bring you close to where you want to be. RCBS case master is great way to check your brass for runout and a number of other things to do with your brass.

Under 5 thou runout should be fine for most purposes. 15 thou is definitely excessive, in my book. Depending on what flavor of target shooting someone dabbles in, run out as high as 2-3 thou can be acceptable. For the really nit-picky (read: anal-retentive) 0-1 is the goal.

Next question is: Do you believe that your bullet runout is limiting your accuracy? Is your gun and shooting technique 'good enough' to realize any appreciable benefit from lower run out? Some people like to fuss about it anyway, as it is a 'feel-good' thing for them to know they covered every possible aspect, and if the bullets don't go in the same hole, at least it wasn't because of *that*.

Monte

Assuming good brass, a lot of runout results from pulling the expander ball out of the case. You can reduce this by removing the expander stem, chucking it in a drill and polishing it with crocus cloth or very fine emery cloth.

Before re-installing in the sizing die, place a neoprene o-ring under the lock nut. I usually set the ball as high as I can, being sure it is below the neck sizing portion of the die. You can help assure the ball is centered within the normal play of the threads by sizing a case and extracting it until the case is barely in the neck of the die, screw expander stem up until you feel it contact inside of case bottle neck and tighten the lock nut. The o-ring will allow slight movement to seek center while locking stem.

A good dry lubricant on inside of case necks also helps concentricity.

Regards,
hm

check my thread about "necks not concentric after neck sizing"???? from this forum back on 3/10/03

Many of the members from this sight, (and several from this thread) responded with quite a few suggestions that will no doubt help you with the explanation you are looking for as well as some great explanations as to just how to get rid of it.

[ 03-20-2003, 01:21: Message edited by: JustC ]

Milanuk...you brought up a good question..am I good enough to notice the diff? I think so, but Iam brand new to reloading, and just like the "science" of reloading I guess..I dont shoot competition, but I expect ALL of my rifles to shoot a half inch or less at 100 yds...Is a RCBS Case Guage a good starting point???
.......sakofan...

Sakofan,

Die choice can also affect this. If you choose, for example, Forster benchrest dies, they are made with several features designed to minimise this problem.

Patrick

Once a case is fireformed, I only neck size and I use a Vickerman inline seating die. My runout is .001 or less. Bob Gemmell at GMW makes the dies in most cals. He's listed on the GMW page at www.castingstuff.com He has a lot of calibers now that he's up and going on them from .17 to .45. I use a couple for cast bullets which were designed for them and a couple for jacket highpower. There is nothing out there that works better.
Dozer

Sakofin the RCBS gage is a good one. Run out becomes more important as range increases. Only you can really determine the level of accuracy you need or are satisfied with. I will say that I firmly believe run out to be the single greatest factor in effecting the accuracy potential of your ammunition. Most people find run out of .005 to be acceptable for hunting ammunition. Varmint rounds need to be held tighter as well as ammunition for match or long range shooting. There are a bunch of ways to minimize run out and you have already gotten much good advice from others on this thread. Different dies respond different ways to such efforts. Get your gage and start experimenting is the best advice I can offer.

First of all, worrying about it isn't worth a thing if you have a chamber that's not perfectly in line with the bore. On a "built gun" this should be so. I was part of an interesting experiment to see if this was worth worrying about for 600 yard loads for service rifle shooting. My friend prepared a run of his standard 600yd load and then measured them with the Sinclair guage for bullet runout. They were seperated in those with runout of 0 to .001 and the culls which went as high as .006. He was shooting of a bench with a 20 power scope in early morning to get a zero wind condition. After shooting several groups and measureing he decided to shot some of the culls, and lo and behold the 2 smallest groups of the experiment. Conclusion, Use a redding or forster seating die and never worry about it again.

Thanks guys, will the Redding and Forester dies jive with my RCBS stuff??? ..sakofan..
I'll also buy the gauge...

I meant, will I have to change my RCBS press with the Redding or Forester dies???
What about the sizing die,Kevin????..sakofan..

Redding and Forster dies will fit your RCBS just fine.