accuracy and bullet run-out

5 thou runout is considered to be good factory ammo IMO. This much runout will cause issue 300m or further if you are shooting at a MOA target or smaller.
2 thou runout is maximum for Long range competition. Anything over is used as sighters for me.
0-1 is achievable through sound handloading practice with good dies and experience.

So in short, yes. Runout causes issue with a point of impact. Really all this depends on the intended target and delivery ability.
 
Spin them and mark the hi point.

Shoot several groups with the mark at 12 o'clock.

Shoot some groups with half the shots at 12 and the other half at 6.

If the latter is bigger - that is the effect of the run out.

Shooting all rounds at 12 will minimize the effect.
 
Been squaring up my dies off of a dime ,, placed onto of the shell holder.. before I tighten the seating nut... better engagement into the lands and groves, that inturn ..
tread the dies and press together. .. matching the upward stroke your press to face of your dies ,,,, which should be square... SHOULD.
square and plumb is a good place to start.
I WILL admit.. I've thrown dies in the pond..

Good luck follow the thousandth if you like benchrest..
I Doooooo..
If not good way to check your hunting ammo..
Did you really miss?
 
Mystic Precision said:
Depends on the bullet, chamber, throat, and potential accuracy of the whole system.

It is not an absolute cause of good or bad... more info.

Jerry
Click to expand...

This, rifles with tight chambers that are reamed true to the axis of the bores are usually acceptably accurate. Sloppy chambers equal wide groupings. Sometimes this can be alleviated by neck sizing only and seating the bullets up against the leade.
 
Ganderite said:
Spin them and mark the hi point.

Shoot several groups with the mark at 12 o'clock.

Shoot some groups with half the shots at 12 and the other half at 6.

If the latter is bigger - that is the effect of the run out.

Shooting all rounds at 12 will minimize the effect.
Click to expand...


Yup, that will work to a point but what a pain in the but. I've got a Martini single shot in 303 British, which has an OVAL, rather than round chamber. It shoots neck sized only ammo really well as long as the small notch filed into the rim is at 12 o'clock.
 
As a matter of coincidence I was going through some of my ammo.

Rem Brass vs Nosler.

Rem factory brass had .0035-.004 runout on case neck before loading and same runout on bullet.

The Nosler brass had .001 before and after loading.
 
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