I have a new built 6mm/06 Ackley improved. I built it upon a montana 99 action with a 28 inch hart 1 in 12 twist barrel. I have redding reloading dies and found that a .243 die works well in forming brass. I was just wondering if anybody had good reloads for a 65 to 80 grain bullet. I was planning on utilizing 70 grain sierra matchkings and hornady v-maxes. Appreciate any info,links , or helpful advice. I thank you much.

Sorry don't have any info for you. I had my own 240PDK. Slightly bigger than the 240Gibbs. Burned out the barrel real quick, used more powder for small gains over the 6mm or 243 so rebarreled in 6mm. Data for the 240Hawk (look up zhat) will be close. Or look at 240 Wby loads your case is about 4% bigger. So in theory your max would be the 240wby TIMES 1.04.

From my experience don't get attached to your barrel.

This is published data for the 240 gibbs. It has 8% more capacity than the 240Wby and about 4% more than yours. Compare these loads to published loads for the 240Wby and you will see very little if any gain.

Have fun hog plinker. I have a 6mm-06 improved which is close to the .240 gibbs. Here are some of mine.
75 gr. MBR bullet-fireformed .270 pmc brass-CCI BR2 primers and 61.6 grs IMR 4831. The outside temp when I tested this load was 75 degrees. result was 4,067 fps @ 15 feet.

61.1 grs RL25 w/ 100 gr sierra flat base bullet and CCI BR2 primers- velocity was 3334, the same as with the 75 gr bullet test! Pressure seemed fine. I intend to refine this load for accuracy. I think it will make a nice deer/antelope load.

95 gr Nosler BT and 53 grains of RL25 went 3195 fps. Same load in fireformed went 2995 fps. Initial goup size was .705 outside spread

56gr H414 70 grain speer = 3811 fps
56gr H414 75 grain MBR = 3733

70 gr Speer/56 grs H414/CCI 250 primer/3811 fps
75 gr MBR bullet/61.6 gr IMR4831/CCI BR2 primer/ 4067 fps. (max)
75 gr MBR bullet/56 grs H414/CCI BR2 primer/3733 fps(accurate-sub .5")
90 gr Sierra/61.1 gr RL25/CCI BR2/3433 fps (nice hunting load)
100 gr Sierra fb/61.1 RL25/CCI BR2/3334 fps (nice hunting load)
100.0 gr Sierra 3572.0 fps CCI BR2 IMR4831 57.5 grs 3.175" 80 dg necked down .270 win PMC

These loads are safe in my rifle..but you should start below them and work up. I also recommend you use magnum primers with this cartridge when you use H414. IMR 4831 seems to be a good all-around powder in my cartridge.