Regarding barrel length for the .223, I think you will find that a lot of extra barrel length in the .223 is not worth the weight, except in very limited applications where you won't be packing your gun alot. Generally, between 20" and 24, or 26" of barrel length in .223, you will get about 30 fps velocity increse per inch. The difference is more significant below 20" and less significant above 26". However, as has been mentioned, there are other variables. AS an example, over the years I owned three different Ruger rifles in .223. Two had 22" barrels and one had a 26" barrel. I discovered they had very long throats, and those long throats really killed the velocity (about 300fps), unless I really cranked up the powder. Now, I shoot a Remington Model 7 with a 20" barrel, and with recommended loads, get better velocities from it than I did from any of the Rugers. I have used barrels as long as 26" but like the light weight of the the M-7 so well that I don't think I will ever go to anything over 22". I think if you are looking for blazing speeds, you will be happier with a .220 Swift or maybe a .22-250. Just keep in mind that .223 barrels last a lot longer than the hotter .22s and they use less powder. Therefore, I would suggest you will find yourself happier in the long run with something around 22". It will be easy to carry.....and don't worry too much about velocity. There are dozens of good bullets out there that will enable the .223 to do about anything you would ask of a .22. One possible exception to my recommendation, and especially for this forum, is that a 24",26", or longer barrel is better for heavier bullets and longer ranges. For those better long range bullets, also remember that you need something in the 7" to 8" twist rate for longer bullets though. If you go with a factory barrel it will have a 12" or 14" twist and will not stabilize long boattail bullets, although they usually will stabilize the 70 gr. Speer, which is a semi-spitzer. Although the Speer is great for larger critters, its semi-spitzer, non-boattail configuration makes it less practical beyond 300 yards. Bottom line- I love the .223 and after about a bizillion rounds have settled on a 20" barrel. I think a 22" is a great compromise. Go with 24, 26, or longer if you really want to squeeze out the velocity and don't mind a varmint weight rifle. I tried them all and ended with 20. If I ever rebarrel I will go with 22" fluted, and keep it light. I believe that, and long barrel life is the delight of the .223. Greg.