I personally have had great success over all with Sierra bullets. But I hand load so I can adjust powder amt seating depth etc to get accuracy in various rifles. As for performance on game they worked with authority when I put the bullet in boiler room. They are not bonded, partitioned or have fancy shaped internal jacket thickness to retain max weight retention. So, they may come apart if you push hard or are shot at close range in the 270.
I've taken many mule deer and tons of yotes with them over the years.
My loads were stiff doses of IMR 4350 and Norma 205. I went for velocity and settled for 0.75 MOA average group size over a lot of years. I stopped stuffing powder in when she hit 3190 FPS out of the 24" Douglas barrel.
It took nearly 30 years to shoot out the barrel.
I downed a young bull moose with 2 shots at around 60 yards. Amazingly both shots exited with vigor. The second shot went through both shoulder blades near the shoulder joint. I was amazed to get complete penetration.
The down side of them was if I hit a dear in the boiler room it ruined the entrance side whole front quarter, rib cage and shoulder. i learned to shoot no closer then 250 yards. At that distance and much further she performed perfectly.
Just tho't I'd chime in......