I do not speak from reading articles but from actually chronographing some of these loads and seeing them used in rifles at our local range.These were 270,308 and 30-06 loads in a variety of rifles from A-bolt to remington 721 to remington pump to browning lever.The 30-06 loading in an a-bolt came closest to meeting the advertised velocity and the 721 also in 30-06 was about 50 fps slower. The blr in 308 was nearly 200fps short.A remington pump in 270 was about 100fps short of published velocity but still showed pressure signs.In all cases these loads did produce more velocity than other loads in these rifles but none met published velocities.Only the a-bolt grouped as well as other loads with the light magnums and the blr shot groups twice as large as it' s favorite load with the other two guns in between.What it really comes down to is that if they shoot well in your rifle they will provide additional velocity although not as much as promised.