The rifle is a Kimber 84M Classic and the box will take a round 2.825" long. I am not in the camp that thinks bullets in one cartridge take up powder space and not in another cartridge! Either the bullet stays in the neck or not. Either the rifle shoots or not.

I have not looked to see if there is room for a longer magazine box and cutting the bolt stop but why not? At least a 1/10" might be gained.

The barrel is now a 260 Rem. I may pick up 100 fps by the change. It's just a idle thought. The rifle will feed 284 factory loads just fine. Magazine capacity is not a concern.

Frank, if you are going to do this on a 2.8" mag box, I think you would be better off w/ a .260AI. I had a M700 done for heavy varmint/target work. 120grs @ 3100fps is easy to get from my 27" bbl.. I would think you could push them @ 3000fps from a slim 23"bbl. I've been thinking now of getting a M700 mnt. in .260 & rechambering. The 6.5x.284 might be fine as long as you don't want to push the long 140gr target type bullets. Maybe a shorter 140gr, like the Speer GS would work out better.

I agree with fredj338, I think you would be better off with a 260 A.I. in a short action with a 2.8" magazine. You would have to seat the 140 gr. bullets so deep to work through the magazine as to reduce your powder capacity thus reducing top accutate velocity to around the 2850 to 2900 fps range. With the 6.5 X 284 ccording to the Fifth Edition Sierra reloading manual 2900 fps was only achieved with two pwoders AA4350 and RL-19. With the 120-125 gr. bullet weights 3100 fps can be achieved. Both of these velocities can be achieved accurately with no pressure issues in a 260 A.I. and still work through a 2.8" magazine with hunting bullets in those two weights. And it does it with less powder and better barrel life. But if you are not a shooter who shoots in volume, barrel life may not be an issue for you.

Don't get me wrong the 6.5 X 284 is a fine cartridge. For the last decade it has ruled 1000 yard high power competition. That says a lot for it's accuracy potential and down range performance. It makes a superb long range deer/antelope cartridge.

With my long throated 6.5 X 284 I can push a 140 gr. class bullet to a little over 3100 fps and a 123 gr. Lapua to 3360 fps. That is quite a lot difference. All because it is thorated so the 140 gr. class of bullets don't cut down on the powder capacity. The 260 A.I. is very good one. For a 6.5 X 284 to be all it can be, it needs to be chambered on a standard lenght action, not a short action.

RiverRat