Cartridge ID

[JimmyHoffa]

Looking for ideas from the HuntWA smart guy experts as to what this cartridge is.

Top is 30-06 full length resized
Bottom is .300 RUM full length resized

Middle is in a 30-06 parent case.  The bullet is .308 diameter.  Front of shoulder is 2.220 inches, rear of shoulder is 2.150 inches, diameter at rear of shoulder is .454 inches.  Shoulder angle looks to be 40 degrees.

My best guess is that this is 30-06 Ackley Improved that has been fireformed and neck resized. (It's about .15 inches longer to the shoulder than I have listed for AI by Nosler.)  Any other guesses?  Is there an extended Ackley or something?

[MountainWalk]

Yeah Jimmy, I'm interested to see what responses show up. So the bullet turned out to be .308?

[JimmyHoffa]

Yes, .308 for all three pictured.  The bullet in the 06 on top is 180 grain Hornady Interlock and the mystery round looks to have the same bullet.

[MountainWalk]

Yes, it does.

[Curly]

30-06 Obermeyer 
Link

[MountainWalk]

Somebody must know.....

[Curly]

Maybe a 30 Gibbs

http://30gibbs.net/index.htm

http://ammoguide.com/?catid=444

[MountainWalk]

Looks awfully close, Curly.  I bought a drawer of junk and four or five of these where in the box.

[AWS]

There are any number of 30 cal wildcats on the 30-06 case.  I could be that someone just ran a AI reamer in a little deeper to get more case capacity, it would be just a 30-06 Improved.  A little harder to form brass but more speed than an AI version, and still enough neck to support the bullet and uses standard brass. A true AI shoulder is actually a little shorter than factory 30-06 as it requires crush fit for fireforming.  Custom reamers are easy to get and you could use an AI die for loading or custom dies can also be made fairly reasonably.  I shoot a 22-204, 6mm-204 and 25-204 and have had custom reamers and die sets made, someone picking up a piece of my brass would be stumped as they have no name.

A 30 gibbs might be it.  Link to Gibbs dimentions.

http://www.google.com/imgres?imgurl=http://www.huntingnet.com/forum/upfiles/14154/AD29E8A85D49431AAF2173DF59041D68.jpg&imgrefurl=http://www.huntingnet.com/forum/reloading/227291-30-gibbs-30-06-improv.html&h=295&w=872&sz=38&tbnid=uHPuZEmTcQ9viM:&tbnh=37&tbnw=110&prev=/search%3Fq%3D30%2Bgibbs%26tbm%3Disch%26tbo%3Du&zoom=1&q=30+gibbs&usg=__eQWfT93HD7KlPVEn01xnNWiz7rs=&docid=qSop1wOcynpIGM&hl=en&sa=X&ei=pd_LUK7VKYfpigK64IBQ&sqi=2&ved=0CDkQ9QEwAg&dur=89