Slight run out seen by naked eye. A problem??

[chaz]

Hi folks, I'm in the process of making up an accurate load for my 6.5CM using Sierra 130 TMK's and Lapua brass.

After making 40 or so, i did some random concentricity checks (only by naked eye on a flat surface), and they were showing slight run-out. I don't have a concentricity gauge, so it's down to a gentle role on a flat surface, and always has been, with no previous problems ever! I'm puzzled by this, as i rarely get any visible run-out. Would this give me inconsistency in my test loads to the point of rendering them pointless?  As a rule i generally always seat the bullets to at least the width of the caliber. I haven't done this in all rounds i've made, but most. And never had any issues that i can recall. Being an ELD type bullet, i also used an ELD seating stem. And sitting the bullet in the stem it seams to fit well. I could seat them around 3mm (give or take) deeper into the case neck. Firstly is this alone likely to help? Or would i be better off using my inertia hammer to bring the bullets out as far as i dare without the bullet coming out of the case, then in affect re-seat them? I usually partly seat bullets then turn them 180 degrees and seat the rest of the way. Although i can't recall if i did this when making up this batch.

Some CONSTRUCTIVE comments would be much appreciated. Apologies for the capitals in this sentence, but I have had a few childish comments the last time i asked for help.

Cheers.

Chaz.

[Andrew]

I doubt it will cause much grief. I had a set of 9.3x57 dies that would pull the necks off center on the expander stroke. I shot beautiful one-hole groups despite the bullets being so canted that some of them wouldn't chamber.

If you can do something to rectify the situation, do it, but an accurate load will still be accurate with minor run out. There is of course, just one way to tell....~Andrew

[gbal]

 As Andrew says- shoot a decent sample and see-you might load some with the 180 turn and  try them. Maybe inertia pull,turn  180 and reseat-but neck tension might be varied-you have no real control-I"d not do this if they shoot accceptably as above.

gbal

 

[chaz]

Cheers folks. A day at the range to try them out it will be then.

Chaz

[gbal]

Chaz, that's the spirit-or 'proof of the pudding',anyhow. 

Far more enjoyable than a visit to SPECSAVERS....    :-).    

Sorry,blame oscar wilde,who could resist everything except temptation(especially on a quiet Sunday)!

g

[VarmLR]

I had the same issues until I bought a VLD seating head for my redding die from Spud.  That improved run-out to very acceptable levels.  Prior to that having tried the Lee seater, the 140 SSTs loaded wouldn't even chamber!  Took me a while to work out what was going on but the VLD seater did the trick.

[onehole]

If your brass is not quite concentric or suspect{Lapua can be way out!!] and your seating tools are also not quite the best fit etc,,,ensure you do not have too much neck tension and rather than just do two seating passes revolve case a few times gradually seating home rather than just the two pass 180.

The human eye can detect very small runout if observed on a perfectly flat surface and if its only small then for most purposes that's good enough,,,,,,,,,if you want a couple of tenths then that's a whole heap of work and everything else to consider alongside!! I wouldn,t be partially knocking out a bullet and trying to refit,,,this will upset neck tension I reckon and making a bad situation worse.....Try the multiple revolving seating for starters,,,,,it does help,,,,,,,O

[Big Al]

Have you tried chambering a round then removing it and comparing the runout again?

[chaz]

5 hours ago, Big Al said:

Have you tried chambering a round then removing it and comparing the runout again?

I've not tried that Al, i'll give it a go. 

Cheers

Chaz