Whice is the better pellet for a high power airgun (1000 fps+) ?
I have both, and the difference is not worth mentioning under perfect conditions, until you start to think about the "theoretical"differences between them.
H & N Barra's are longer have a traditional diabolo waist, and have a slightly more pointed tip. This presents a slightly larger surface area to push through the air. Being longer they are subject to greater wind pressure, dynamic instability in flight, and require higher twist rate to stabilise, so good for high FPS rifles. BC in 0.024
JSB Heavy, is shorter, has no Diabolo waist, has a true domed head therefore aeordynamically more efficient. BC 0.029..........can be used well in lower FPS rifles, if you can trust your trajectory settings and allow for the extra drop.
At longer ranges or at lower FPS, the JSB Heavy will fly higher (less clicks) be less affected by cross wind (less kentucky windage), It's more bullet shaped body with flat sides creates less turbulence in flight. (Turbulence around the pellet will increase the effect wind has on it at range)
Both Pellets are extremely well made, high quality lead, and worth using to try out in your given Barrel. The differences are theoretical,......until such time as you test them and find which you like the characteristics of best. They do shoot differently.
IMHO MY pick: JSB Heavy. (Although I still have 4 tins to work through of Barra Match ...lol)