Ok folks, I recently posted a thread that ended up with a dozen pages on the difference between the saami spec and Akley 40 degree specs of the 280 AI. Heres the new issue I am having. I bought a brand new Dakota 97 Hunter in 280 AI. Fireformed some casings. After full length resizing they will hardly go back into the chamber. During close inspection it is obvious to the naked eye that there is a difference in the fire case shoulder and the resized case. From my previous post I made it known that I confirmed with Dakota that my gun is a 40 degree pre sammi chamber. My dies are over 10 years old confirming from Redding info that they are the orginal spec 40 degree. I have emailed Dakota but its a holiday weekend. So, what is the issue. Why is the fire formed case not "fireformed"!? Is there a headspace issue? Should I buy a neck sizer die? Is the chamber not cut complete? Not sure it will show up in the pics but the case on the right is the fireformed vs the left being full length resized. You may be able to see that the fire formed is "rounded" and the resized has a sharp shoulder. Been reloading for over 10 years. I had a factory REm 700 280 rechambered to ackley with NO issues. The Dakota was VERY expensive and to have ANY issue is less then acceptable! Thanks in advance for your thoughts.
I would say try a neck sizer die. I have two sets of dies for my 280AI. A set of Lee full length dies and a Redding comp seater and neck sizer die. A neck sizer die is not expensive. Its worth a shot. But I have heard once you neck size a case from a certain gun that you can only use the case in that gun again unless you full length resize it. But have never tried it myself. Keep us posted
Neck sizing only will get you past your problem and the Dakota should shoot fine but the rounded weatherby looking shoulder is odd. I have heard there are several different 40º Ackley dimensions out there and some may have a rounded shoulder. A full charge fire form casing should be fully formed so I think there is something wrong with the chamber or it's different 280 AI variation.
I was thinking about this and it occurred to me that Dakota is part of Freedom Group. Thats the same people who have destroyed Remington and Marlin. My guess is you have a defective chamber. Hopefully since you paid so much for it they will take care of it but it's Freedom Group so they may declare it within specifications and stick you with it.
Dakota confirmed that the chamber is the 40 degree Ackley not the Nosler SAMMI spec.
280 Rem ammo slides in smooth and bolt closes very easy. The fire formed pre resized cases work like butter in and out of the chamber.
Resized case causes the bolt to open/close very stiff.
One of the members said it best "looks like a Weatherby rounded shoulder".
I think Dakota needs to recut the chamber.
So much for being able to "share" ammo with my kids Red Hawk Rifle 280 AI that is currently being built.
And I am just gonna put this out there, the gun was sticker priced at 4495. The dealer was doing a 20% sale so I bought it for 3600. This gun should load, fire and clean itself! And I am selling three of my other guns to pay off the CC bill.....just my luck...