Re: 6.5-06 Ackley
The 6.5-284 runs about 2.25x's the freebore with a shorter neck than the -06 case does. My straight 6.5-06 reamer has 0.080 or 0.088" of freebore as opposed to the common 0.180 or 0.188" of freebore in the 284 based round. (I know one is 0.x88 and the other 0.x80 but I can't remember from the top of my head).
The longer neck in the 6.5-06 seems to be helping with the throat life in the 6.5-06's that I've put together. They're certainly not easy on the barrel life, though after 900 rounds one is showing 0.047" of lands erosion and the other is appx. 750 rounds in and showing 0.044". The one rifle has been pounded a lot harder with hot loads, that's my suspicion as to why the lands have moved a lot more.
I wouldn't bother with an AI version unless your buddy is truly a speed demon chaser, with 28" tubes both of these rifles are running the 140 Berger at 3150-3175fps. The loads are HOT but brass life is still around 5 cycles before the pockets are too loose to use. Both rifles are being fed Winchester 270 brass that's trimmed to length and sized. No FF'ing or other fussing is needed.
They're match rifles and strings are normally in the 8-12 rounds/8 minutes range. Sometimes less, depends on the stage, but they definitely get hot quickly.