Expanding dies???

[FamilyMan]

So I have searched this and have found some really good info and I am going to get one to start using. However in my searching I have come up with a few questions I juke t find the answers to
1. Is using an expander die in conjunction with a FL bushing die an more ideal/better way to go for more uniform necks and less run out?
2. If I go that route am I suppose to use a different size bushing than just the typical .001-.003 smaller than loaded?
3. Would using this method take the place of 2 step sizing with bushing dies referred to by German Salazar? Or would it be used in conjunction with it?
4. Would there be any additional need to turn necks for this?

All this is going to be for a 6.5 Creedmoor 1:8 twist Bartlein barrel that is being chambered and fitted by Chad @ Long Rifles Inc.
Thanks for your help
Brett

 

[9H_Cracka]

Re: Expanding dies???

German (a friend of mine) uses the two step method with approaching or exceeding .006" neck OD change from fired to sized before bullet insertion. If you are managing your neck change to .005" or less, then no "need" per his research for the two steps.

Most any factory chamber would require the two step method per his research, and a lot of "field" rifle match chambers, but some flat range chambers could be done in one step.

Separate from this is the whole OD vs ID as the last thing touched before bullet seating. There are some that believe ID is the "best" place to touch last as the end diameter is less effected by neck wall variance when touching the ID last. Springback differences when touching the ID are the variable, versus when touching the OD last (bushing die) the ID will vary directly based on the neck wall thickness/uniformity AND springback differences....

There is a reason ID mandrels exist from the BR world.

Net/net, you (or at least I am) are trying to balance 3 things here - one, your time sitting at the reloading bench, two, bullet tension consistency which has a great deal of impact on your velocity ES, and three, concentricity. I rate item one and two most important, with concentricity being a distant third, for I have never been able to document a concentricity problem that affected the shooting I do.

If you do get hung up on concentricity, I would suggest you make your loading techniques overall driven to provide low extreme spread, THEN add a concentricity checker/corrector to the mix as your last step. That way you can correct it, rather than just sort/reject the ammo.

 

[Deadshot2]

Re: Expanding dies???

I do all expanding on my .308 win with a mandrel die with initial sizing done with either a Forster F/L Benchrest die which I've removed the expander ball from or a Forster Neck Size/Shoulder Bump Bushing die which doesn't have an expander ball to begin with.

End result for me has been far lower ES, SD, and MAD values with correspondingly smaller groups at all ranges.

I check concentricity but am being more inclined to believe it's not as important as uniform neck tension. Another benefit of using a mandrel expander is that any doughnut that's been forming is no longer on the inside of the case, but outside.

 

[FamilyMan]

Re: Expanding dies???

Deadshot2 do you use a different size bushing than normal or just the standard measurement?