Runout

[bsekf]

This my first attempt at precisian reloading.
After resizing my cases have .001 to .0015 runout but after seating a bullet the runout is about .005. I am using a regular Redding seating die, is that the best I can expect? I am shooting a 6 X 222mag AI so I would have to have a custom seater made or can you interchange some with Forster Benchrest seaters like you can with Lee collet dies using washers and etc? For the Forster to work do you need a perfect chamber fit or is just the length and neck critical? I was thinking 6PPC or 6BR and a pile of washers.

Thanks,

Bill

 

[284driver]

Very low runout is typical after fireforming. the case takes the shape of the chamber for the most part. IMO,unless you turn the necks to clean up the inconsistancies in neck thickness, you will have some bullet runout. the thicker side of the neck tends to cock the bullet a hair. that's probably what you are seeing.

 

[fdshuster]

bsekf: You did not mention what bullets you are using. If they are the V-Max type with the sharp point,check your seating stem to be sure it is not touching the tip of the bullet. Some seating stems will "bottom out" with the sharp nose profile bullets. Bullet runnout can drive you crazy. I've checked factory rounds w/ both the Sinclair & RCBS gages, and found some to have as much as .015" of bullet runout. So much for the theory of "precision factory" ammo! Runouts of .003" and less do not seem to effect my group sizes, but more than that, the bullet tip & case head is marked,black magic marker), and if the problem continues, that case will be kept for max. 100 yd, first round fouling, etc. I have had some success in seating in 2 or 3 passes: seat approx. 1/3, rotate case 1/3, seat 1/3, rotate then final seat. As skyav8r said, neck wall thickness is another factor: measure your neck walls with a tubing mic. I've found some of the lower quality brass to vary by as much as .004".