223 barrel length needed to achieve max velocity

[WaterRat]

Hi
Been thinking about getting a new carbine looks like it will be the model 10 Precision carbine in 223 with 20" barrel if I do.
Was wondering if the 20" barrel is long enough to burn up all of the powder and archive max velocity shooting hand loads using 55-70 grain bullets?

OR Would I be better off with a different rifle and longer barrel?
Either way I want to stick with 223 since I already load for it.
This would be used for informal bench shooting.
I don't really need another rifle but have just about run out of guns to work up loads for

I have a model 10 24" heavy barrel in 223 and a Lone Eagle pistol in 223 so I figure I need something in between right?

[tiny68]

You need to match your powder to the barrel length for optimum burn. Maximum velocity will always be with the longer barrels up to about 32-34" from have I reminder. Gains of 5-25 fps per inch have been reported but reports vary greatly. In my quest for speed I have learned that speed and accuracy don't always go hand and hand. Don't worry if your not at max velocity with a high BC bullet because they commonly don't shot the best at the highest speeds. You can choose a slightly faster burning powder for shorter barrels and slower powders for longer barrels to get the best speeds from each barrel. Luck, Tim

[gotcha]

Personally I'd opt for a 24" to 26" bbl. just because I'd rather have more than I need than less. I've got 2, 26" .223's with 12 & 9 twists & .223AI with 8 twist. This way I can maximize performance for the wide range of bullets now available for .223 Rem. as well as, extend accuracy range with my .223AI and heavies. 600 yd PD hits are not uncommon with the AI. Just another angle to consider. Good luck with your buy :)

[Rustydust]

Personally I'd opt for a 24" to 26" bbl. just because I'd rather have more than I need than less. I've got 2, 26" .223's with 12 & 9 twists & .223AI with 8 twist. This way I can maximize performance for the wide range of bullets now available for .223 Rem. as well as, extend accuracy range with my .223AI and heavies. 600 yd PD hits are not uncommon with the AI. Just another angle to consider. Good luck with your buy :)

+1

My longest prairie dog kill ever was a smidge over 700 yards with my .223 AI. It has a 26" barrel. I guess that I could have made the shot just as easily (bit of luck there you know) with a 24" barrel or even a 22" barrel but the longer tube gives a bit more speed and gets the blast a little further from your face. Not a bad thing when hunting colony varmints.