Neck Sizing Issues

[Dean]

I'm having an issue with my neck sizing.

I have been loading for a little over a year and I just started loading for my first 6BR. I started by turning the necks of the new Lapau brass just to cleam them up, then I seated five bullets into empty unprimed cases and measured the outside of the necks and came out with .269 .According to the Sinclair catalog for Wilson bushings you subtract 2-3 thou. for your bushing size, so I bought a .266 and a .267 and I started with the .267 .The virgin brass sized and seated ok.After fireing I prepped the brass as normal,clean,deprime,size) I then charged all of the cases,50)to continue load development and started the seating process.

This is when the trouble starts,I seated the first one with a Wilson hand die,,the neck die is also a Wilson) and a K+M arbor press.I measure it with a Stoney Point tool and as I'm putting pressure on the calipers the round starts to get shorter...obviously the neck is to loose so I change to the smaller bushing and although it is tighter, if I chamber a round that is seated to be jammed .010" it will push the bullet in about .004".

The bullets seated easier this time compared to when they were virgin but I was told that this is common.This is my first time using an arbor press and hand dies so I didn't know what to expect as far as pressure I would need for the seating process.

I have already ordered a .265" bushing and hope this will do the trick.Is it normal to have this much variation from virgin to fired cases in the neck.

Hang on guys I'm almost done.

I measured the ID of the bushings and they both run .002" smaller than what is stamped on them. Is this the way they all are?

Sorry for the long rant,

Dean

 

[BoydAllen]

What kind of tool are you using to measure your neck diameter? If you are using a dial caliper, it may have accuracy issues. A good 1" mic. that measures to ten thousandths should be in your reloading kit. The other problem may be that the neck of your chamber may be large enough that the fired brass is quite a bit larger than it would be in a tight neck chamber, and when sizing down from this diamater, there may be more spring back. In any case, a tighter bushing should fix you up.

 

[Dean]

Thanks Boyd,

I use a digital caliper,but a quality mic is on my wish list.

As far as the size of the neck in the chamber goes,it's a Pac-Nor barrel and all though I didn't order a tight neck I did have to turn the neck on the Stone-Point modified case.It was .272 but was to big to fit in the neck of the chamber so I turned it to match the rest of my cases at.269 .

Is the outside diameter of a no-turn loaded round actually .272?

Thanks,
Dean

 

[BoydAllen]

Seat a bullet in an unturned case and measure the OD of the neck over the base of the bullet,if it is a hand made match bullet, or anywhere over the shank of a factory bullet, and you will have your answer. I have seen some inexpensive Chinese made micrometers that seemed to be OK. Also, you might check out Ebay.