Throating the new rifle

[muleman]

Rifle and load details:
Rem 700 action - standard magazine
280AI
Mag length - 3.60
I loaded 160gr AB and 150gr LRAB sample rounds to take measurements off of. I'll pick up some 175gr LRABs today as well. Wish I could find just a couple of the 168gr LRABs!
I seated the bullets so that the beginning of the bearing surface was at the bottom of the neck. There is quite the difference between the two. I used a Hornaday bullet comparator.
150LRAB - COAL 3.360, To Comparator 2.689 I think this would be to Lands?
160AB - COAL 3.490, To Comparator 2.907
175LRAB - Jake's Data looks pretty similar to the 160AB
The neck is really long on the 280AI and I probably could leave these longer. I have the mag length.
My question to you all is" What should I throat this barrel to?"
I've compared all the LRABs and the 160AB on a ballistics program and all the LRABs compare about the same for down range performance; they leave the 160AB in the dust.
The LRABs all have about 1700fps, 1000fpe and 23-26MOA drop at 1K.(200 yd. zero)
The 160AB is only running 1478fps, 775fpe and 27moa at that distance.
There is a huge difference between the 150LRAB and the 160AB at least in the distance to lands and I'm sure that the 168 and 175LRABs will fall in between.
Let's all hear your opinions......... You know what they say everybody has one!
Thanks for your input!
Scott

 

[IdahoCTD]

I'd be more inclined to set the throat tight (no jump) for the 160AB and 175LRAB. That would mean you'd have to seat them a little deeper for the jump they usually like. That would also allow the 150LRAB to work without pulling it out of the case a lot.

 

[SJB358]

I am with Nathan. Have it set up for the bullet you want to shoot out of it. All of them are winner's really. Even the 160 AB is a great one till you are taking it out REALLY far..