I've been reloading both these calibers for quite sometime, and today I found quite to my amazement that my win 94 .307 perfectly cycles .308 brass. Knowing that the dimensions of these two cartridges are identical - except for the rim, and that they are both loaded to the same 52,000 cup pressure limits, why not use .308 brass with flat nose bullets? Any thoughts?

Never fired or had a .307, but doesn't it
headspace on the rim? (isn't that why it's
there???) If it headspaces on the shoulder,
like the .308. I don't see any big problem
with it. But again, I don't really know, so
don't take my word for it...

reloader-1

Reloader-1, your right, the .307 does headspace on the rim, but since the dimensions are exactly the same as the .308, why can't it headspace on the shoulder? People have been doing this with magnum cartridges for years - sizing so that it headspaces not on the belt, but on the shoulder.

I agree, it should work, but, you don't likely have the same grip on the case for extraction, so you may get into trouble there. Also, the case will not be suported as well in the head area, there will be a big gap where the rimmed case used to go, I suggest starting well below max. Maybe well below starting loads might be better!

[ 01-09-2003, 16:41: Message edited by: John Y Cannuck ]

I don't have the SAAMI specs in front of me, but as I recall, the .307 is limited to lower pressures than the .308. The action of the gun for which it is chambered is certainly not as strong as actions for .308's.

Otherwise, yes, a .308 may be fired in a .307 chamber (provided it is loaded within pressure limits permissable in the particular gun). It will simply headspace on the shoulder. Be cautious, however, since the .307 chamber was cut with the idea that it would headspace on the rim, you may find the base-to-shoulder dimension of your .307 chamber on the long side.

The problem is that you will have to extract the fired case with a cleaning rod. Why are we having this discussion, anyway?