I haven�t seen that much information about �bullet runout� and since buying an RCBS Case Master, was wondering just how much attention is given to this when reloading. I�ve checked some of my M-4 squirrel loads and found that most of them had 4 and 5 thous. runout. I ran some of the loaded rounds through a F L sizer and tried them at the range today. They weren�t bragin size groups but better than one ones that hadn�t been FL sized. Would like to hear others experience.

Bullet runout is huge when chasing small groups. If your canting the projectile .006 left one time and the next ones .008 the other way it might be "good enough", but you won't get "BugHoles!"
.002 is usually considered max for extremely accurate varmint rounds, a bench rester would laugh at .002. It's all in how far you want to take it, and how good is good enough on a personal level.
When seeking that magic .000 runout ammo a lot figures into it, some of it's brass some of it's dies and some of it's brass and die set up.
Further a factory off the shelf rifle might well not even be able to "Shoot the difference" in .0005 and .003, so it might well be a waste of time to take it to the limit in seeking reloading perfection depending on the weapon.
A number of my most accurate rifles have tight necks and custom chambers. After culling 50 out of 500 pieces of brass and spending a lot of time on prep, turning necks etc, using in line dies and such my select lots of the best brass will run .000 to possibly .00025. These rifles will agg 5 shot groups in the .1's and .2's if the shooter does his part.
That's my personal take on runout, in a nutshell it all depends on what the rifles capable of and how far you want to go to provide it.

Archer,

Most will tell you that 0.003" is considered adiquate for varmint hunting, I would go a bit farther and say that .003" is tha max I would recommend for use out of a factory rifle.

There are several factor to look at when trying to figure out what limit you want to put on your ammo as far as bullet run outs go.

1. At what range will the loads be used for.

2. What is the accuracy level needed for the hunting this ammo will be used for.

If your shooting a 221 FB at gophers and p.dogs at less then 200 yards, anything under 0.005" bullet run out will more then likely be enough to score a hit.

If your shooting chucks at 1000 yards, you better have your bullet run outs held in the 0.001" to 0.0015" at the most.

To the same degree, if your hunting gophers at 400 yards, you will need very tight grouping ammo, Again, sub 0.002" is a must.

If your hunting coyotes out to 300 yards, a run out again of anything under 0.005" will probably do for this type of hunting.

One thing to remember though about bullet run-out, it is a function of case neck run-out and the stability of your seating die system.

If your using a conventional seater such as those from RCBS, even if your case neck run outs are perfect, you will still have a high percentage of bullet run outs over 0.005" with finished ammo.

One can tweak and tune full length sizing dies to get very good neck run-outs, usually in the 0.001" or less range. Still this does not matter if half your ammo has +0.005" bullet run out from a standard seater die.

The cure, an in-line bullet seater such as those from Redding or Forster. Generally these will limit bullet run out to roughly that of the case neck run out. There can still be some odd bullet run outs with these dies, but they are reduced to an extremely low percentage of the total lot of ammo.

From doing alot of extreme range shooting with several rounds up to and including the 50 BMG, neck and bullet run out are of highest importance to long range accuracy.

Not only does teh rifle have to be built perfectly and the shooter have to have extreme marksman skills but the ammo also has to be of equal standard in quality.

A custom BR quality rifle will shoot poor run-out ammo better then a factory rifle simply because of its tight chamber specs, but both rifles will shoot dramatically better with ammo that has the lowest possible run-outs.

Good Shooting!!!

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