I have a CZ 550 tactical in .308. I am planning on rebarreling it in a .260. I have heard that with the .308 and the .260 barrel length (from 20'' to 26'') doesn't make a difference because all the powder is burned before it reaches 20'' mark. My question is, Is this true? If I can get away with a 20'' barrel and save the weight from a 26'' I would love it, but I don't know if this would hold up. There are a lot of 20'' .308s out there, but do they lose velocity. I am more interested in what a .260 would do. If anyone has experience with this please let me know. Thanks.