Sort of to compare figure 260 Rem with a 142 ABLR. versus a 270 win with a 150 ABLR. 24" barrels. I have both 260 Remington 26" and a 270 win with a 26" barrel. The 270 win is a 1-8 twist and not even going to compare because the 270 win with the 170 Bergers smokes it. so I have some data for that. I can get 75 fps +/- more with 260 Rem vs 6.5 Creed. I'll give the Creed the nod and give it 260 Rem velocity.
6.5 Creed with 142 gr ABLR Muzzel velocity approximately 2,868 fps and 2,590 ft lbs. Sea level 200 yd zero 10 mph cross wind at 1,000 yds 1,611.5 fps 819 ft lbs energy. Drift 1.59 mils, drop 7.2 mills.
So of to the 24" 270 win 1-10 twist 150 gr ABLR. 3,048 fps velocity, 3,095 for lbs energy at the muzzle. At 1000 yds 1.65 mills drift, 6.6 mills drop. Velocity 1,638 fps 894 ft lbs.
Based on the above the only area the Creedmoor wins is drift by .06 mills at 1,000 yds. The 270 win has 75 more ft lbs energy, 28 fps higher velocity. and a drop of .06 mills less drop. What does this really mean. The 270 win with a 1-10 twist beats a 260 Rem 1-8 twist to 1,000 yds. Yes inside 300 yds though the 270 win sleighs the 260 Rem. 270 win 1550 gr velocity 2,575 fps 2,208 energy MPBR 316 yds. 260 Rem 2,445 fps 1,885 ft lbs energy MPBR 300 yds.
So the 270 win is superior inside 1,000 yds They both go transonic at 1,350 yds. The 260 Rem does have an advantage thought in felt recoil. If we assume Both as 10 lbs rifles, the felt recoil for the 260 Rem loaded as above is 12.5 ft lbs recoil energy. The 270 win loaded as above 18.9 ft lbs.
If we go with a 1-8 twist 270 win with a 170 Berger we can get approximately 2,870 fps from a 24" barrel. While it is 7.0 Mills drop and 1.46 Mills drift kicks ***, and the muzzle energy is 3,100 ft lbs, the felt recoils for a 10 lbs rifle is 19.5 ft lbs. So for repetitive shooting, say a PRS Match the softer shooter is more desirable. In then end the 260 Rem is a much more efficient energy with a relatively low recoil. For hunting 270 win all day unless you are recoil sensitive.
I went with a 270 win 1-8 twist 26" barrel in my barrel change McGowen Precision 700 Remage. Al little heavy 12.4 lbs but at 2,930 fps with the 170 Berger she is a crazy performing 270 . This round generates a 16.4 lbs calculated felt recoil so with my brake I am guessing 8.2 ft lbs felt recoil. So this comparison should help someone understand the dynamics of different cartridges. inside 300 yds any of these rifles will kill if shot placement is accurate, then we can get into the 308 win and 7 -08s and alike. Accuracy kills, you can't miss fast enough.