neck thicknesses

[ARlife4me]

is there a "best" or "better" thickness for necks in regards to longevity, spring back and/or tension? forget about accuracy and pressure for the time. is there a good comparable average that's acceptable? spring back might not be limited to hardness if necks are to thick? if the chamber is reamed to accept the brass of thicker necks, would it still be workable? cartridge and caliber might not have anything to do is this, but if neck tension is well enough to hold the bullet would it still make any difference?

just wondering as for designing a cartridge is question reasons.

 

[MagnumManiac]

One thing I will tell you about necks, there is no magic thickness, only clearance in your chambers, this NEEDS to be .003" MINIMUM. If your neck does not allow this because it is too thick, then it needs turning down.
Personally, I like neck thickness to be uniform at .0135"-.014" and no thinner. Several brands of quality brass fall into this and that's what you base your chamber on, not the other way around.

Cheers.

 

[ARlife4me]

One thing I will tell you about necks, there is no magic thickness, only clearance in your chambers, this NEEDS to be .003" MINIMUM. If your neck does not allow this because it is too thick, then it needs turning down.
Personally, I like neck thickness to be uniform at .0135"-.014" and no thinner. Several brands of quality brass fall into this and that's what you base your chamber on, not the other way around.

Cheers.

at the thickness you prefer it at is more of a preference than what wouldn't work? clearance is understandable for proper chambering and extracting and would do a chamber to match brass numbers. say if i went with .020" on a 30cal (.308") then chamber neck needs to be .351 or .354 to be clear?

 

[MagnumManiac]

The thickness I prefer is based on numbers taken from the brass I chose, which just so happens to be accommodated by several brands, then I cut the chambers to suit. To make the brass fit, it needs turning to be .014" at the upper end or .0135" at the lower end.

What you're quoting, being .351"-.354" is probably close, but I would have a solid finished neck number FIRST to work off, no point cutting your chamber then discover it's too big or small. What brass has .020" thick necks?
The clearance is necessary only so the neck expands, if it doesn't and pinches the bullet, it will give you very high pressures.
When designing a chamber for custom applications, you need all dimensions first. SAAMI is very bad at making chambers too large, it's unavoidable because ALL brass has to fit it, but YOU can control this with a custom reamer.
Even a 'Match' chambers can be too large.

Cheers.

 

[ARlife4me]

The thickness I prefer is based on numbers taken from the brass I chose, which just so happens to be accommodated by several brands, then I cut the chambers to suit. To make the brass fit, it needs turning to be .014" at the upper end or .0135" at the lower end.

What you're quoting, being .351"-.354" is probably close, but I would have a solid finished neck number FIRST to work off, no point cutting your chamber then discover it's too big or small. What brass has .020" thick necks?
The clearance is necessary only so the neck expands, if it doesn't and pinches the bullet, it will give you very high pressures.
When designing a chamber for custom applications, you need all dimensions first. SAAMI is very bad at making chambers too large, it's unavoidable because ALL brass has to fit it, but YOU can control this with a custom reamer.
Even a 'Match' chambers can be too large.

Cheers.

i was adding up from post #2 for chamber neck id. a 308 bullet w/+ .003" (not sure if it's half the amount or total clearance) + .020" neck on brass.