.243 improved .270 neck?

[2009scoutsout]

Working brass to fireform for a new rifle a 243 imp with a .270 neck chamber wanted to pick others brains before I turn necks and fireform , with my math .011-.0115 for a turned neck thickness to allow .002 for brass expansion does this compute?
Thank you !

 

[SeabeeKen]

.022+.243=0.265.265 .005 clearance

.024+.243=0.267. .003 clearance

 

[6MMsteve]

I would go for more clearance .005 at least that's me ...I don't want any issues I use no turn got away from neck turning worked more on trigger control and my tendencies of concentration. but that's me it has improved my shooting a bunch... more clearance less worry but I'm not a great shooter

 

[gunsandgunsmithing]

I would go for more clearance .005 at least that's me ...I don't want any issues I use no turn got away from neck turning worked more on trigger control and my tendencies of concentration. but that's me it has improved my shooting a bunch... more clearance less worry but I'm not a great shooter

.005 is more than I like but I agree that more is better than too tight. And with new brass, it seems the thickness is not consistent from lot to lot, which makes me lean more toward more clearance on no turn stuff. Yes, I think your time is better spent shooting than it is turning necks, too.

The more I shoot no turn stuff, the more I like it and the less I think it matters..fwiw

 

[Will Henry]

I would likely aim for .0115". With a .270 neck, you will have to turn. WH

 

[gunsandgunsmithing]

I would likely aim for .0115". With a .270 neck, you will have to turn. WH

 

[gunsandgunsmithing]

He'd still have .004ish. I'd call that plenty.
On smaller cases like a ppc or br, I like no more than .003 and no less than .002, but that's total difference, loaded round to chamber. At least I don't think I'm missing anything there. Nominal bullet diameter of .243+.0115+.0115=.266 loaded round in a .270 chamber, should be .004 clearance, right?

 

[AlNyhus]

I'd forget the math. Seat a bullet and measure the neck O.D. over the heel.of the bullet. Then turn one and seat a bullet to verify the O.D. Turn again, as needed.

Good shootin' -Al

 

[gunsandgunsmithing]

I'd forget the math. Seat a bullet and measure the neck O.D. over the heel.of the bullet. Then turn one and seat a bullet to verify the O.D. Turn again, as needed.

Good shootin' -Al

Exactly right. Measuring neck thickness can work but even at best, it's the least accurate way to measure and it stacks tolerances. The loaded round dimension is what matters and it's what enters the chamber.