I have been using the search function to learn a lot of information, but I have not been able to learn the following

1. What is the differnece between a Collet Die and a Bushing Die and what are each of them used for?

2. What does the term "Run Out" mean?

3. Lastly I have read much on the importance of seating a bullet straight. Will a Dillon 550 Progresive reloader load a round as straight as a single stage "C" or "D" cast type press. I have learned that Forster and Wilson type presses seat very straight, but I think that may be more then I need. I just wanted to load my speicalty Dies (Lyman "M" Die, Lee Universal Decapper and a Lee Factory Crimp Die, etc.) into another Dillon Tool head and keep them set that way. Thanks in advance.

1. A collet die has a collet which first slips over the neck of the case, and then the case/collet assembly pass through a reduced diameter orifice that causes the collet to squeeze the neck, thereby reducing it's diameter.

A bushing die has a bushing that is smaller in diameter than the neck. The neck is pushed through the bushing, causing the neck to compress and reduce its diameter.

A bushing die is more versatile because you can change out one bushing for another that is smaller or larger based on how much neck tension you want.

2. Rubout is the dregree to which the bullet nose points away from the bore centerline. Some people think that runout is not relevant because the throat will realign the bullet as it enters the bore. Others disagree stating that a bullet that enters crooked, will be deformed by the bore, thereby reducing its accuracy.

The goal is to load the most concentric azmmo possible. If you're anal, then .001" is the goal. If you're happy with 3" groups at 100 yards, then any commercial die will do the job.

3. If you use Forster or Redding competition dies, you will be able to load concentric ammo with your 550 just as you can with a Wilson hand die.

One thing you should take into account is that the CASE causes runout more than the die you use to load it. You can take a crfappy case and load it with a Wilson die and still have .010" runout. Case prep is very important.

Ralph-

I think you paint a pretty grim picture of anything that is not benchrest quality.

I think the difference of using a $30 die set versus something more expensive like a $100 benchrest set is useful for benchrest shooters.

If I bought a regular Group A RCBS Die Set, I would most likely get ammo that shoot well under 3", more likely 1" or less depending on the load.

I load a 7X57 with an old set of cheap Lyman Dies and I get groups that measure as good as .75"

-Spencer

Adding to what Ralph said:

The main difference between a collet die and any other kind is that it does not have an expander. This is important in that the expander does not have to be pulled back thru the neck which can pull the neck off line. The collet die has a long rod which the neck in compressed onto rather than the expander ball type which sizes the neck smaller and then the expander ball is pulled through and expands the neck back to specs. This pulling action is what you avoid by collett dies.

Run out is measurable with a concentricity gauge like the RCBS case master. This thing will drive you crazy chasing concentricity, but it may be preferable than being oblivious to what is going on. You lay the case down and roll it and it has a point which bears on the case neck, seated bullet, or anything else you want to measure and the dial will measure to .001". It allows you to get more involved like indexing rounds so you load them with the largest runout always on the same side, neck reaming to uniform neck wall thickness, etc.

You may not have to buy benchrest dies. I wish I had bought a Redding Body Die and a Lee Collet Die in each caliber. Works better for me and I can neck size or full length size without lubing inside the neck and useing expander ball type dies. Cheaper too.

Spencer,

One needs the best possible dies (chamber type)to load adequate ammo if the press is not well aligned, as in the case of a progressive like the 550.

Ralph

Forgot to mention

Bought a Redding Bushing Type Die and the appropriate bushing and it yielded the largest runout ever. After posting here, I found out other people were having the same problem. It uses an expander ball to size the neck like the regular dies. Didn't work for me.

Reloading has come a long ways from thirty years ago.....there's far far more useless tools than ever.
95% of reloading accuracy is from
1...picking the right bullet 75%
2...picking the right powder 20%
7000 other things including runout ...5%

Vapodog, not to hijack this thread, but what would be some specifics you would lend into 'picking the right bullet'.
I usually pick a bullet based on the characteristics I like in the bullet as opposed to thnking about which bullet would work in a particular rifle or cartridge.
Regards--D.

Ralph and Woods, thanks for taking the time to answer, your posts were very helpful. This reloading started as a way to shoot more while spending less. I can see it is going to be a hobby in and of itself.