Hello All,

Today if fired twenty rounds at 100 yards, from a rest, through my Encore, .30-30, muzzletamed, 12" barrel pistol. I hope I gave all the deatils, I've been known not to.

The first 10 cases were full length, then neck sized and did not group at all well. Pattern is a much better description.

The second 10 were neck sized only. The first three from this group were in a group measuring 1.5", high left. I adjusted the scope and fired three more shots, two in one ragged hole (such a nice term)and one to the left of the bull, measuring 1.375". To use a techincal term, WTF!!

I guess I'll neck size till length is a problem, but has anyone had any similar occurances?

I really like the group, just don't understand the process.

Let the comments begin, and happy holidays,

Lee

The difference could be in the dies. I have better groups with FL sizing and longer brass life with neck sizing. The next guy may be just the opposite. One difference could be the amount of the neck that you are sizing. If you don't have the neck sizer set to go all the way down the neck then you have different tension on the seated bullets compared to the FL.
Good Luck with the puzzle.

Hey Lee

What were the headspace measurements on the once fired brass?

How far back did you push the shoulder when you Full Length Sized?

Dwight, the neck size die is set to go all the way down the neck.

Woods, headspace on my frame is .0015". I set the die for .001". There is no noticeable (<.0005") difference between resized and once fired brass. This brass has been reloaded two times, and I expect a change in the headspace soon. I just hate driving that damn pin out to remove the extractor, OTT uses a set screw, a much better idea.

Thank you both, and Happy Holidays,

Lee

Oh yeah, nice Pronghorn.

Normally there is no difference in accuracy between neck sizing and full length. One thing that will ruin accuracy is a die that sizes the neck too much and the expander is hard to pull out. This almost always causes bad neck and bullet runout.
Take some of each and compare bullet runout to see if there is a difference. You should try for .002" or less.
A little extra headspace doesn't matter much, it just shortens case life. The 30-30 is supposed to headspace on the rim but it helps if the shoulder is used also, it should just kiss the chamber.
I used to send all of my size dies in and have them lapped out for minimum sizing but they now charge to do it. The very worst cases to size too hard are the Weatherby calibers, guaranteed bent shoulders.

Hey Lee, Somewhere many years ago I read where it is best to Resize Cases for the Contenders so the action must be Snapped Shut on a Case, as opposed to being able to close it gently. That would cause the Case to be held under a bit of Compressive Tension along the CenterLine of the Chamber, not laying on the bottom of the Chamber. At that time I was already P-FLRing Cases, so it made good sense to me to do it that way.

When I got my Contender, I ended up with two cartridges that didn['t work that way. One was a 44Mag barrel which of course headspaces off the rim, so there was no "Shoulder".

The other barrel was for a 22Hornet which Case is so weak that you can't tell if you are P-FLRing it. So I just set the FL-Die to Resize about 1/3rd of the Neck and it always closed easy.
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Neither of those barrels were very accurate, which was partially due to Chamber Dimensions which seemed to be on the High Side of the Spec. The Contenders can be aggravating to deal with, but the 30-30 should work real well in it by P-FLRing the Cases.

The only way to know if the Neck Sizing works as well is to try it and see how it does.

Best of luck to you.