reloading. neck sizing only. affect on groups?

[vujade]

From what I'm reading, neck sizing fire formed cases should increase accuracy.

Are there any instances when it would not?

Or, all things the same (powder, primer, bullet, etc.) why would groups get larger (odd flyers) when you neck size?

On some heavier loads - (once that didn't show any high pressure signs before) (and WAY below printed maximums), the bolt is a little sticky when pulling up to extract the bolt.

I'll also note that this particular rifle seems to have a VERY tight chamber. (It loads factory rounds ok but what i thought was full size resized and worked for another rifle wouldn't fit this rifle).

thanks!

[Dolomite_supafly]

Neck sizing only should not have any affect on accuracy. If anything it might increase it by reducing variables.

Now if you were FL sizing before and went to neck sizing you are going to have to work loads up again to tweak the loads.

Hard extraction and a sticky bolt are normal for neck sized guns after a few firings when neck sizing only. I would say ever 4-5 loadings you need to use a body die to bump things back into shape.

A lot of factory ammo is smaller than SAAMI spec. That is so they WILL work in any gun. And when you resize them down to what is SAAMI spec they can seem a bit tight.

Dolomite

[Ray Z]

+1 For what Dolomite said. If you're shooting off the bench it works. If you're shooting in the field or autoloading out of a magazine you are asking for trouble.