Neck Turning Related Question?

[jrob300]

I've been reloading for over 30 years. Not a noob.

My question concerns an issue I've run into reloading for my 300WM. I have a LR load that works very well. It performs seamlessly between Nosler and Federal brass. Recently I bought quite a bit of Winchester brass, as it was all I could get and my other brass is getting really tired.

I did all the usual brass prep and sorting I normally do. The one exception was that the case necks were very inconsistent. So I turned them *close* to full exposure on some of the worst. They varied from .0115 to .0170" I turned them to .0125" The Nosler/Federal are fairly consistent from .0135-.0140".

I OCW tested and found that the Win. brass shot smallest at almost exactly the same velocity as the Nosler/Federal using 1 more gr. of powder (they weigh less and have more H2O capacity).

BUT... they will not group the same. They're shooting 1 1/2 to 2x size groups.

I mention neck sizing as it's the only variable that stands out to me...

Any thought's from you reloading mavens?

John

 

[sinister]

Re: Neck Turning Related Question?

Were your groups from first fire forming? They may settle down after first sizing.

 

[308sako]

Re: Neck Turning Related Question?

deleted in protest

 

[jrob300]

Re: Neck Turning Related Question?

Yeah,

I though the same thing, but I'm on my second firing and they're not tightening up like I'd expect. There's something different about the way they're behaving.

I neck size using the Lee collet die and I get almost zero runout w/ about .002" tension.

I shouldn't have to anneal after a neck turn, should I? They do seem to seat a *little* harder than my annealed brass.

John

 

[wnroscoe]

Re: Neck Turning Related Question?

Skip necksizing and bump the shoulders .001" to .0015" and tune your load at 300 yards. We used to sort WW & Rem brass by weight after turning the necks and I felt it made a difference. Debur the flash hole and uniform the primer pockets as well.

My 6BR and 6 Dasher will put 10 shots completely in a dime sized group at 330 yards but, if I move the bullet into the lands as little as .005", the groups open to .75moa. I say this because I've yet to see a rifle that didn’t tighten up when seating depth was tuned at distance once the load was determined.

Granted, Secant Ogive vs Tangent Ogive bullets will react differently but, adjusting the seating depth will make a difference.

 

[jrob300]

Re: Neck Turning Related Question?

William,

I fully prep the brass as you mentioned with the exception of pocket uniforming. I noticed that the primers are *really* hard to press in. Enough to make we wince... So there's one thing.

I had not thought about seating depth. My 200 SMK load just does not care. The 208 Amax's really wanted to be close to the lands and will not group at mag. length. .005 and .010" off have both delivered tight groups.

So the Winchester brass might prefer a different loading depth? So you tune load with OCW and then vary depth?

thanks for the advice,

John

 

[wnroscoe]

Re: Neck Turning Related Question?

With VLD's, I've always adjusted the seating depth as the last step. With SMK's, Scenars, Berger LTB's etc. I've just loaded to mag length and ran them.

The Amax will be best tuned by seating depth as a last step.