Rechambering a .308 Win barrel to .300 Win Mag.

[5pins]

Anyone cut a .300 Win Mag chamber into an existing .308 Win chamber? I have a new Shilen short chambered barrel, but I need a .300 Win Mag barrel. I don’t see any reason it can’t be done, but I have never done it before.

 

[FisherT&C]

yes you can do it. I've converted some old 1903's to 300 Win Mag. A 308 should be no problem.

 

[5pins]

yes you can do it. I've converted some old 1903's to 300 Win Mag. A 308 should be no problem.

Perfect, thanks.

 

[RTH1800]

Going to need to verify contour is safe.

 

[Terry Cross]

Make sure your 308 barrel has a twist rate you can live with when throwing heavy/long bullets.

./

 

[5pins]

Make sure your 308 barrel has a twist rate you can live with when throwing heavy/long bullets.

./

It's a 1 in 10. Right now I'm using a 1 in 9, and it shoots the 220gr Sierra MK very well, but I can go lighter if need be.

Going to need to verify contour is safe.

I think it's the standard varmint, so it should be fine.

I also have a used, about 20 round, Shilen chambered in .308 Win with a 1 in 8 twist, but it's a straight contour.

 

[MJC]

I also have a used, about 20 round, Shilen chambered in .308 Win with a 1 in 8 twist, but it's a straight contour.

According to Sierra, the 1:8 twist is right for their 230's.