Concentricity and accuracy question

[clrems77]

Ive been told anything under .003 is considered concentric and good. Im always getting a handful of rounds that measures .003-.005 in every batch i load. Is there something I'm doing wrong to obtain these readings and how much difference am I going to see with the .005? Shooting out to 900 yards

Im loading for 300wm (Norma brass, Nosler LR bullets) and 6.5cm (Nosler brass Berger hybrid target bullets).

Thanks!

 

[memo43]

Alot of it will come from the equipment that you use as well as brass prep, as well as the quality of brass.
Measure concentricity after each step to figure out where it is being induced
I try an achive 0-3 for my bolt guns and 3-5 for gas guns.
Best way to tell what the difference will be is to shoot batches of rounds out to a know distance
I use 500 yards and shoot at paper targets (cardboard boxes with picknic plates) measure out what
each batch of rounds perform.
I have found as little as an 1/8" in group difference.
if you are shooting steal targets or paper targets then the difference will be in score.
How ever steal targets a hit is a hit if that makes sense.

 

[M14AMU]

If you are.....DO NOT 'honk' down too tightly your resize die in the press and also if not done already...put an O ring under the locking collar. If you're withdrawing the deprimer rod back through the case with a button on it....those sometimes can forcefully pull the neck outward during the extraction process. I dip the mouth of my cases in very fine graphite when resizing and the ease with which the button is withdrawn is quite obvious! Make certain you have no dirt/or a kernel of powder in the groove of your shell holder! Run a few cases through the resizer and check with your concentric gauge. If runout is acceptable at this point your next step of seating will bear further info! I have always used Wilson inline seating tools and most of the time run-out is usually no more than .0015"! Are you FL resizing or neck sizing?? Check your run-out on the straight shank/bearing surface of the bullet; not near the ogive!