RE: 280 remington into ackley improved
 

Yall are forgetting to tell him about the excessive headspace if you just neck up .270 brass. Especially considering the .280ai shoulder is further forward than .270. What I do is neck up .270 brass to 30-06, THEN neck back down to .280ai neck. That allows for the partial length 30-06 diameter neck to headspace .280ai from.

RE: 280 remington into ackley improved
 

You're right, stalkingbear....... Guess I forgot to refer to one of my previous posts that described exactly what you say....

RE: 280 remington into ackley improved
 

"It's not that I mind atlering a cartridge but for all that you've got to go threw on this one, is the end result really worth all the trouble and expense ???? Sure the cases will last longer with the sharp shoulder, you may gain 200 or so feet per second.. seems like it's alot for a minimal gain... what will it do that the standard .280 won't, expecially in a hunting firearm.. As for brass, get some LAPUA 30/06 brass and have at it... you'll farther ahead with it than the others.. Still can't see this much for so little... "

With the minimal gain of 200fps more why would you use the 300 win mag vs the 30-06? The reason the 280AI or any AI cartridge is better than the parenet cartridge is because it can use slower burning powders to acheive higher velocity at the same or below the parent cartridge pressures. Not to mention it will allow you to use heavy for caliber bullets with better down range performance. The higher velocity translates into flater trajectory downrange. The benefits of the AI chamber are numerous.

I have a 280AI and I chose to fire form my brass using bullets vs the cream of wheat method. I did it this way so I could break in the barrel with the practice rounds and also to familiarize myself with the new rifle. I bought 100 pieces of Rem brass and loaded them up to standard 280 pressures. Then I trimmed them to length and started load development.
My rifle does well with RL-22 with the 150gr Barnes and 168gr match kings. H4831sc works well with the Nosler 120 and 140s.