Neck thickness,neck diameter question.

[Kelly Timoffee]

My question is what will different brass neck thicknesses effects be on accuracy , pressure , etc......or will it not differ between the two, only consistency within the loaded batch of brass?

.284" bullet.

First brass is RP with neck thickness on average of .0125".Loaded round neck diameter is .309"

Second brass is Lapua with neck thickness on average of .015".Loaded round neck diameter is .315"

The necks have been turned to uniform the thicknesses.All brass has been annealed.

Maximum OD of the neck as per specifications is .315"

 

[stubblejumper]

I usually find that I see higher pressures with Lapua cases. That could be due to thicker case walls resulting in less internal capacity.

 

[explorin2]

If one were to assume the body thickness was equal to the neck thickness then one could expect higher pressures.

Through use, necks can become thicker while walls (body) become thinner, so in this situation one could maybe expect a lower pressure.

Lymans 49th edition reloading manual states .320 for max neck dia., but is for winchester cases.