Quote Yes but most .270 barrels are 22" long standard. (There are some companies now making them 24"). The ballistic data is from testing in 24" barrels. So a "normal" length 22" barrel will lose about 50 fps from the published data of 3060 fps with a 130 gr bullet. Of course there's the Hornady "superperformance" ammo. End Quote
The two .270 rifles I have are 22" and both get 3100 fps or slightly over with 130 gr bullets.
Yes, different rifles vary. Let each do as he will, but my minimum barrel length on a hunting rifle for long ranges is 22".
Jack O'Connor claimed 3200 fps from his 22" barrel .270 with 130 grain bullets, but 3150 has been my top vel with reasonable pressures.
Regards,
Jerry