Got a 300 win mag with dbm, did I error?

http://i951.photobucket.com/albums/a...B02C25371B.jpg
Using Sinclair hex nut 3.84 to lands and 3.64 is all I can get in mag. The only other bullet I have on hand is 178 amax and those will have to be jumped 80.
I have the predator hunter in 243 and the LRP in 260 and didn't run into this problem. I know its shares 308 mag. I didn't know long action mag would be this short.
This is a non catalog long range hunter and I know I could single load but it makes no sense to me. It's my first long action bolt and got it to round out my 30 caliber lineup.
Does anyone have any luck jumping this far? I know I'll be limited on my powder charge..if I had known this I would have gone with the hinged floor plate I detest! I haven't lost hope yet.

Hinged floorplate and DBM still share the same box. Load it up to mag length and shoot it, you may be surprised.

Thanks for the reply. I didn't know that about them being the same.
I'm waiting on bullets to become available to load but picked up the cheapest rounds i could find, a box of managed recoil 150 grain Remington. I figured I'd use them for break in and have brass at the same time...it doesn't like them!! It shot better with brake closed. 2 1/2 inches vs. 3. However, I'm not drawing a conclusion on the guns accuracy with a magnum round that is 200fps slower than their 308 load.

I have to shoot mine single shot.
Tooooo far out to go in clip.



PSE EVO 60 Lbs.
Blacked out

I guess I have to work up two loads. One for shoulder pounding on the bench and one for hunting.