20 vt barrel lenght

[20vt]

HI long time viewer first time post.I am building a switch barrel 20 vt.The rifle is a rem 700vssf .223. I have a Lilja 1-12 twist that is the same contour a the rem. varmint barrel.I would like leave the barrel as long as possible which is 27.5 inches .Which after chamber would still have 24.5 inches of rifling,my thoughs are would be esayier to reach 3800 fbs with 32 gr.bullets and not have a hot load in doing so.This rifle will be shot of a bench at paper or at PDogs,for 95% of it life thats why i don;t mind the longer barrel lenght.What do you guys think . thanks 20VT

[montdoug]

Welcome to the site, sorry it took so long for someone to respond. My .20 VarTarg has a 22 inch barrel and my working load is 3,785ish or close enough to 3,800 it makes no difference. I could possibly go faster but there's no need.
While I'm not a gun smith I can't see the .221 case needing more than a 22to max 24 inch barrel to get maximum velocity out of any round using it. At a certain point there becomes a situation of diminishing returns and it's going to go the other direction and start slowing down.
If more velocity is a big concern build a .20 Tactical or something similar. Keep us posted.

[20vt]

Thanks for that info Montdoug It would be ineresting to know what the max barrel lenght=max velosty is in the 20 vt,you mite be right in saying that 24 inches is all you need. THANKS for the reply 20VT

[Oleman]

Taking a look at the following it would be my guess that over 24" of barrel on the VT won't buy you anything.

http://www.bullberry.com/204Rugerdata.html

[montdoug]

If 23 inches is max for the .204 with it's much larger boiler room then even 23 inches is too much for the .20VT. When I built mine and considered exactly this topic I figured 22 inches would get all of the .20 VT's case capacity, if the max length in the .204 is 23 inches even my 22 incher might be a bit too long in the .20 VT. Keep in mind it isn't all about velocity, if velocity in and of itself is the main issue get a bigger case, it's easily handled.

[20vt]

thanks guys i can see now that i will go with a shorter barrel,iam thinking a 24 inch which should give me 22inches of rifling.Once again thanks 20vt

[NZVarminter]

After reading the bullberry test on barrel lenght for the 204, and Fred concluding that you only loose 50 fps going from 24 to 21". I chopped my Cooper 204 down to 21"

Sierra 39's were doing 3950-4000fps with 28.3g of H4985 Extreme (AR2206h) out of the factory 24" bbl.

Same load is now only doing 3650-3700!, so I have lost more like 200fps!@#$

Cheers

Grant