Then you probably will have to make the choice between destructive and trajectory.
Meaning . . . you can slow it down . . but then you would loose the excellent trajectory that this chambering has,at 300yds. You can turn it into a 270Win or even a 6.8SPC with velocity.
You possibly could be less destructive using one of the solid copper offerings. Barnes offers from 85gr ( I use these in my 6.8) on up.
Do not use the Hornady 120gr SST. They shed their jacket even at the 6.8 vels. The Hornady GMX line might be another option. They are a guilding material and a little harder than the solid copper bullets.
The .277" bullets are designed for use in the 270Win. Anything much slower (my 6.8SPC) or anything faster (270WSM) will need some expiermentation.
For your usage possibly a solid copper bullet of between 120 and 140grs. Remembering . . . these are much longer.
Let us know what you find out. I have a friend that has been trying to sell me a heavy bbl Browning chambered in 270WSM. I would like to turn it into my longer range coyote gun using a lightweight bullet at high velocity. --- SAWMAN