340 WBY ,custom chamber, starting load question

[kuduman]

Would like to try two bullets,,, custom chamber so no long freebore. Bullet #1 is Barnes TTSX , 225gn. that can be loaded safely to a .090" jump (clip is limiting getting any closer).. 2nd bullet is a Swift A-Frame, 250 gn. and be safely loaded to have a .020" jump..Are the starting loads in the manuals too high for not having all that Weatherby freebore (.375") ??? Many THANKS for the time and advice

 

[MagnumManiac]

Hmmmm, I wouldn't even be shooting factory ammo in a short throated Weatherby chamber.
When I was running a 340, I had .500" freebore and was still only running 100fps faster than my 338WM in 26" barrels.
The 1MoA I was getting with the 340 just wasn't doing it for me.

I would be using the start loads as max loads if it were me.

Cheers.