The Howa is a good enough rifle. The 6.5 Creedmoor is a 2000 yard cartridge with 25% less recoil than 308, 75% less than 300 WM and is more accurate than either. Cost of factory match ammo is about the same as 308 and about 1/2 the price of 300 WM match loads. And accurate match loads are just as readily available. You can buy cheap plinking ammo in 308 for less and find it easier.
The 260 was the inspiration for the 6.5 CM. While they are very similar, the 6.5 CM corrects design flaws that the 260 has. The 260 was designed as a deer cartridge shooting 120 gr bullets. A 260 holds slightly more powder and in theory should be faster, and with 120 gr or lighter bullets is. When loaded with 140-147 gr match bullets that you need for long range work they have to be seated deep in the case in order to fit in the magazine and chamber. That limits powder capacity and reduces velocity. Also, all 260 barrels are twisted for the lighter bullets and don't shoot the heavier bullets accurately.
The long range target shooters discovered that if they re-barreled their 260 rifles with barrels twisted to shoot heavy bullets, with longer chambers designed to shoot the longer bullets, if they modified the magazines to hold the longer bullets, and finally if they loaded the 260 ammo to a longer OAL and used off the charts loads they could get much better performance. If you want to buy a 260 and do all of those modifications and hand load special ammo you can match 6.5 CM performance. Or you could just buy a 6.5 CM rifle and off the shelf ammo and do the same thing.
The 6.5 does everything a 308 does, and does it better. The best thing you can say about 308 is that it is close enough to 6.5 CM out to about 400 yards that most people wouldn't notice. Other than the 25% reduction in recoil. Beyond 400 yards the 6.5 CM starts pulling away. Even the best 308 loads become unstable at 1300ish yards, the 6.5 will remain stable to around 2000 yards. A 300 WM is only good for another 200-300 yards.
And while Howa is good, I'd save up a bit and buy this. About $900 in blue. The 20" barrel will get you well past 1000 yards. If you want to push it to 2000 get the 24" barrel.
http://www.tikka.fi/en-us/rifles/tikka-t3x/t3x-compact-tactical-rifle