I am not kidding. I could guess but that is what it would be, just a guess. If I was on Millionare, I would have to "phone a friend".

Basically it's the amount of wobble a cartridge that is out of line has. This can be from an off center case or an off center bullet. It can also refer to just a case or just a bullet that is not straight, i.e. the point is not the center, but usually means how much off center the bullet is sitting in the case. This can be caused by a bullet being crooked in the case or the case mouth tipped out of alingment with the case.

Well that seems clear as mud. Some of the other guys may be able to help you better.

Run Out is what you do when the wife finds out you bought another gun, cause boy is she mad! Bob explained it well. Also check out gunnersden.com and click on run out for some good pics. and tips to prevent run out.

Near perfect would be "a straight line of sight from center of flashhole to center of muzzle". There are a few things in between those two points. Chamber,case, bullet, and barrel. Goal is to make that bullet start straight and leave straight. Once past the muzzle "the bullet" is on it's own.

"Runout", as you asked about it as a handloader could be viewed as a spinning cartridge looked at it from front and rear. Any "wobble" that you would see is "runout".

Cheezywan


"Roll" one of your cartridges on a mirror to observe "runout".

I am not kidding. I could guess but that is what it would be, just a guess. If I was on Millionare, I would have to "phone a friend".

Do you shoot pool Chief? A stick that wobbles when you roll it on the table has lots of runout. A stick that rolls even (hard to the find in the bars I go to) has less runout.

So, that's where all the lumber from the Oklahoma National Forests went to! :D

So, that's where all the lumber from the Oklahoma National Forests went to! :D

Can't decide if we need to keep some for fire wood or turn it all into poll cues. Was 78 degrees here Monday and snowed yesterday. Love the weather here....you miss it don't you:D

"Run out" is the measurement of something round on it's "axis"(center line), "axial" run out is measured along the length, on a radius (usually the out side edge):confused:
Then there's "perpendicular" run out and "parallel" run out too!:confused::confused:

Yea, what Bob said!:rolleyes:

Thanks guys. If I would have guessed I would have been wrong. I call that straightness. Who knew?

Chief,

Runout is just the degree of eccentricity of a circular path about some point on any axis you choose. The term literally comes from the idea that when the part runs (spins) it does so out of line, the line being the running axis. It doesn't matter whether that error is cause by a bend or by the ends of a straight rod being held off center. I could, for example, chuck a perfectly straight rod in the independent four-jaw chuck on my lathe, lean a dial indicator up against it, and if the jaws didn't happen to hold the rod exactly on the lathe spindle axis, when I turned the chuck, the dial indicator would move, showing the eccentricity with respect to the lathe axis. The piece is then said to have runout in the lathe.

Incidentally, if the rod is perfectly circular in cross section, the dial indicator tip will be moved away from the axis by some maximum amount when the chuck turns the highest point in the eccentric rotation against it, then move toward the axis by the same amount when you turn the chuck 180 degrees. Thus, the total amount of movement shown on the dial will be twice the amount by which the axis of the rod is off the lathe center. In other words, it indicates twice the displacement needed to move the rod axis in line with the lathe spindle axis. For this reason, and to distinguish the indicator reading from the needed correction, you will see the term TIR often employed. This stands for Total Indicated Runout.

Runout is not limited to being with respect to a third item, like the lathe spindle. As was mentioned before, it can be due to a bend, in which case it is with respect to whatever axis you spin the rod on to see the eccentricity. Typically, to use TIR to find the runout of a bent item, you support the ends of that item between two centers or two aligned V blocks, put the indicator on the middle and rotate the item to look for movement of the indicator, as shown here (http://www.tec-ease.com/tips/november-99.htm). This is what is usually done with cartridges. The tip and base are supported and the dial indicator is placed against the bullet right where it emerges from the case mouth. The idea is to get the indicator to show you how badly the bullet is tipped off the case axis. Even after the bullet enters the rifling, a small portion of that tipping can remain. This causes the bullet to wobble in flight and can typically be responsible for up to one M.O.A. or so of group size on a target.

Down here we call it WOBBLE.

Actually, wobble is a different phenomenon. It is when the axis of rotation itself is moving around angularly. As a spinning top runs down you see it start to wobble until the wobble gets so big it falls over. Runout is only with respect to a fixed rotation axis.

The Wikipedia has a description of the earth's wobbles here (http://en.wikipedia.org/wiki/Chandler_wobble).

Yall are getting to deep for me. I think I will just "run out" to the "Wobble House" and get me some breakfast.

Try thinking of run out as cross-eyed cartridges in which the case looks one way and the bullet another.

Wobble results from run out because the bullet starts out of line with the bore.

I just think of it as axial misalignment where the axes of interest are the bullet and the barrel. If the bullet is out of alignment you will get wabble and that will have negative affects on accuracy. The pool cue analogy is great.

Actually, the pool cue has runout (middle not running true when it is spun with the ends on axis and vice-versa) and the cartridge has runout, but one of the results of using a cartridge with more runout than another is added bullet wobble in the form of nutation.