The Firing Line Forums - View Single Post - Making 7-08 from 308 brass

M16 · October 18, 1999, 09:51 PM

Steve, what could be happening is when you neck down the .308 this causes they neck to thicken. What you will need to do is ream the necks. RCBS makes an attachment for their case trimmer that reams the inside of the necks while also turning down the outside of the neck. Whenever you neck down brass the neck thickens. When you chamber this round the fit is so tight that there is not enough room for the brass to expand to release the bullet. When this happens pressures skyrocket. This is especially true when you try to neck down military brass as it is thicker than commercial brass.

October 18, 1999, 09:51 PM	#5
M16 Senior Member Join Date: September 16, 1999 Posts: 490	Steve, what could be happening is when you neck down the .308 this causes they neck to thicken. What you will need to do is ream the necks. RCBS makes an attachment for their case trimmer that reams the inside of the necks while also turning down the outside of the neck. Whenever you neck down brass the neck thickens. When you chamber this round the fit is so tight that there is not enough room for the brass to expand to release the bullet. When this happens pressures skyrocket. This is especially true when you try to neck down military brass as it is thicker than commercial brass.