I want to have one of these built for shooting the 75 gr. bullets. I plan on doing it for the least amount of money and was planning on buying a factory 223 with the right twist and have it rechambered/bolt face changed etc. Savage seems to be the one that barrels their 223's with the 1:9, and remingtons new sps tactical has the right twist but a 20 inch barrel. I am looking for some insight on how much velocity would be lost in the 20 inch barrel v. the 26". Any info or ideas are appreciated. Thanks.