7x57 reloading problem

637e

Good afternoon All , I've prepaired my cases , i.e.sized ,chamfered the necks ,uniformed the primer pockets,etc. I then checked case neck run-out. 0 to 1 one thousandth .I then seated a bullet. Twenty thousandths under oal. Then checked run-out a just back of bullet tip .Had .012 run-out. I then tried several more . anywhere from .008 to .014 run-out. I partially seated one then indexed the case about 1/4 turn. No improvement. I then tried indexing a case several times . No improvement .I'm using a Bonanza Co-axial press and bonanza benchrest dies ,norma cases , with 140 grain serria pro-hunter bullets .This one has me stumped !!Any suggestions to get the damned things straight ?? Regards , 637e

HandgunHTR52

Try checking the runout of the bullets themselves. Your runout measurements may be due to imperfections in the bullet themselves.

I will add one more comment. Try shooting them and see how they shoot. If they shoot well, then I wouldn't worry about it. Depending on what you are shooting them in and for what reason, there shouldn't be any need to be worried about runout.

5mmgunguy

I agree, try shooting some. See how they shoot. If they shoot good don't worry about it.

mrbruce

Loosen up the nut on the stem a little and seat a bullet with it loose, then tighten the nut back down
while keeping the handle down or up depending on how yours works..
Same thing with the seater die, loosen the lock ring and put pressure up on the ram so it contacts the base of the die and them tighten the lock ring back down.
This will all help sometimes....

Mobuck

Your case necks could be thicker on one side. I've seen quite a lot of this in new cases lately. Outside neck turning is the best remedy.

JustC

find one with .001"-.002" runout. Loosen the seating stem and back it off 1/4 turn. Run the seated round with minimal runout up into the die,...the turn the seater stem back down until it makes contact. You have now squared the seater stem. Tighten the ring and try seating some more.

Runout mostly comes from the seating stage,..NOT the sizing stage. Most brass will have at least .002"+ variance in neck wall thickness (unless lapua, norma, RWS, etc). You can turn the high spots down to take up some of this,..but you'll need several hundred dollars worth of tools. A neck thickness mic (I use sinclair built with a Starret mic) and a neck turning tool with appropriate mandral and expander iron.

sandwarrior

637e,

I'm in agreement with the two major things suggested here and that is to square up the seater and neck turn.

The other thing I question is your choice of dies. Because I'm not familiar with Bonanza dies. I'm more familiar with Wilson and Forster bushing type dies(for extreme accuracy anyways). I can't say Bonanza dies aren't good. I just don't know them.