Savage99
04-16-2015, 09:55 AM
I made 308's from 30-06 and liked it. I found a bunch of military brass in the reload room and decided to try this, now I want to make other cartridge brass from the military stuff (so I don't have different ID's on the head stamp).
Anyway, here is my question; What should the neck wall thickness be? I have not seen a source for this measurement. I am going to be purchasing a Lyman outside neck trimmer shortly and the book "Cartridge Conversions.....".
Here is what I have done so far:
Cartridges of the World, 11th edition, chapter 20 (Cartridge ID by Measurements), the number under "rim thickness" didn't make sense so I took bullet diameter and subtracted this from "rim diameter" and divided by 2 and came up with a number that made sense.
SAAMI diagrams-did the same math and came up with different numbers from Cartridges....(didn't make a table, just random notes)
This table is from the SAAMI diagrams
308 .3435-.3090=.0345/2=.01725 parent (mil)
30-06 .3397-.3090=.0307/2=.01535 parent (mil)
25-06 .2900-.2575=.0326/2=.0163 parent (mil)
22-250 .2540-.2245=.0295/2=.0147 to be made
243 .2760-.2430=.0330/2=.0165 to be made
250Sav .2856-.2580=.0276/2=.0138 to be made
300Sav .3390-.3090=.0300/2=.0150 to be made
I am using a case gauge and calipers (the very tip)
So what should the neck wall thickness be? I want to be as accurate as possible and I know I can only go out 3 decimal points.
I am an Engineering Technician and question things when the numbers don't match up.
Anyway, here is my question; What should the neck wall thickness be? I have not seen a source for this measurement. I am going to be purchasing a Lyman outside neck trimmer shortly and the book "Cartridge Conversions.....".
Here is what I have done so far:
Cartridges of the World, 11th edition, chapter 20 (Cartridge ID by Measurements), the number under "rim thickness" didn't make sense so I took bullet diameter and subtracted this from "rim diameter" and divided by 2 and came up with a number that made sense.
SAAMI diagrams-did the same math and came up with different numbers from Cartridges....(didn't make a table, just random notes)
This table is from the SAAMI diagrams
308 .3435-.3090=.0345/2=.01725 parent (mil)
30-06 .3397-.3090=.0307/2=.01535 parent (mil)
25-06 .2900-.2575=.0326/2=.0163 parent (mil)
22-250 .2540-.2245=.0295/2=.0147 to be made
243 .2760-.2430=.0330/2=.0165 to be made
250Sav .2856-.2580=.0276/2=.0138 to be made
300Sav .3390-.3090=.0300/2=.0150 to be made
I am using a case gauge and calipers (the very tip)
So what should the neck wall thickness be? I want to be as accurate as possible and I know I can only go out 3 decimal points.
I am an Engineering Technician and question things when the numbers don't match up.