I built myself one over 3 years ago, I can say I fell in love with this gun/cartrige. I have an 8 twist 3 groove 26" long # 7 taper. I shoot the 140 grain a-max at 2920fps with H4831sc. At 600 yards when I do my part it's a 1/2 MOA rifle. I have used it to kill 10 deer and lopes the last 3 years. Ranges from 75 to 609 yards. I only had one Bullet "failure" but that animal expiered after a 30 yard dash. I think it along with the 6.5x55 and standard 260 rem are the perfect class of cartriges for deer sized animals. No feeding issues with my gun.
If you do a search you'll find alot of info here on the .260 AI mostly positive can't speak for the feeding as mine is a single shot but for me this is the best cartridge for varmints, deer, and long range prairie dogs...i'll always own a 260 AI.
Wouldn't the case capacity of a 6.5x55 and a .260 AI be about the same? I want to go to a 6.5 for my deer rifle. I love my 30-06, but It has more power than needed, and less range.
I have a .260 imp built on a Savage action and have never had a feeding issue. It started life as a 600 yard gun but now in a different stock it gets used for silhouette and hunting. It has done very well at all the tasks mentioned.