Stuntman8n,
Unfortunately with the M70, the action you have will only handle standard length rounds such as the 7mm Rem Mag.
If your only concerned with trajectory, but want less recoil, your options are a pretty short list but there are some good ones on it.
First off you could go to a 270 Wby Mag but recoil will be very similiar to your 7mm, basically identical.
Probably the best option for flat shooting and lower recoil would be the 264 Win Mag. The 264 got a real bad rap early on but it is a great long range round with proper bullets.
Another option is to leave teh rifle a 7mm Rem Mag and have a quality brake installed.
Good Shooting!!
Kirby Allen(50)