Neck Tension Problems--The Cause?...

[BCB]

I have been reloading some 6.8mm SPC the past month…

It was new Remington brass and I finally got it all fire formed to the chamber of my Contender…

I am now up to 4 or 5 times reloading these cases. I had good neck tension in the beginning as the expander plug indicated a nice tight fit as it was removed from the case during the sizing process…

The last time I was sizing some of them, the expander plug didn’t even appear to touch the inside of the neck—no resistance or sound as the case was withdrawn from the sizing die…

The cases have been trimmed one time and then only a small amount of stretch was noted…

This rifle was shooting amazing for only having tried a couple of bullets and a couple of powders. Now, I am getting an occasional flyer and I suspect it is a neck tension thing…

I wonder what might have caused the necks to become thinner and the inside is not sized down as much as it was when the cases were new?...

Thanks...BCB

[Calamity Jake]

The brass is getting hard from shooting/sizing therefore your getting more spring back, you need to anneal
the neck shoulder area, this will soften the brass in that area reducing springback.

[Mk42gunner]

Yeah, it sounds to me like that particular lot of brass is a "load three times then anneal" lot.

Robert

[leftiye]

The fireforming and etc. has also hardened the necks. Also sounds like the sizing/neck thickness/expander ball are close to minimum at acting upon the brass. Brass can wear enough to not size in benchrest neck dies with neck turned brass. May be like that.

[BCB]

Well, I annealed a couple and that did not solve the problem...

I even heated one until it was red colored. It was soft enough to crunch the neck just with finger pressure. Sized it and the expander did not touch it...

One strange thing, I could get some of the necks red and others simply would not turn red...

I checked other brass--junk stuff of different calibers--and the all got red in minimal time...

I wonder why some of the Remington 6.8 brass will not heat that hot?...

Thanks...BCB

[BCB]

Went back to basics...

Sized a case in the 6.8 die and the expander plug did not touch on the way out...

So, being a .277" caliber, be darned if I don't have several RCBS 270 Winchester dies...

So, I took the sized case from the Hornady die and put it into the 270 Winchester die, just to see if the expander plug in it would touch the neck--it did...

Hornady expander plug--0.275" and the RCBS expander plug--0.276"

I wonder if this minimal amount of some cases being expanded and some not with the Hornady die would cause neck tension problems bad enough to cause an occasional flyer--and that is what they are...

I absolutely know the crosshairs are on the dot when the rifle fires...

BCB

[TXGunNut]

I think you may be onto something, won't know until you load a few and take them to the range. I used to figure I'd gotten my money's worth out of certain cartridge cases after about five firings. Nowadays some rifles/cartridges are letting me use brass much longer.