Velocity loss in 18" barrel .243?

[didactic]

I just bought a Ruger American Compact .243 for my daughter-in-law, who is sleight of build and short of stature. It has an 18" barrel with a 1:9 twist.
Does anybody have an idea of how much velocity she'll be giving away? My own guesstimate is 250-300 fps, but until we can get it on a chronograph, is there anything better?

 

[rickiesrevenge]

You're in the right ballpark. Thats normally what I loose in my xp-100's compared to rifles.

Aaron

 

[bsekf]

I am shooting a 18 inch 6x47L and use Varget because it is a little faster. Theory is that the powder all burns in the barrel. Getting great accuracy and I am only shooting 500 yards, so don't worry about the speed.

Bill

 

[goneshootinginAZ]

Here is a reference that may help. The writer below lost 226 fps going from 24" to 18" using factory 80 and 100 grain factory ammunition. You might do better if you handload and can use a faster powder as suggested above.

http://rifleshooter.com/2016/04/243-winchester-effect-of-barrel-length-on-velocity/

 

[Chief 101]

I have a Rem 600 in 243, and it only gives up maybe 100fps...for me its only numbers, no lack of real world performance...