If the runner is running in a circular track then yes when something or someone is moving in a circular motion at a constant speed they are indeed accelerating. They’re accelerating because the direction of the velocity vector is changing
When firing straight up: v^2 = u^2 - 2gh, where v = final velocity = 0, u = initial velocity, g = gravitational acceleration, h = maximum height attained.
Then, 0 = u^2 - 2gh u = Sqrt (2gh) ---- (1)
When firing at 45°, Initial velocity, U = u Sin 45 = Sqrt (2gh)·Sin 45
Maximum height, H = U^2*(Sin Ф)^2/2g
substituting; H = [Sqrt (2gh)·Sin 45]^2*(Sin 45)^2]/2g H = [2gh*(Sin 45)^2*(Sin 45)^2]/2g H = [h*(Sin 45)^4] = h/4
Therefore, maximum height when the gun fires at 45° is a quarter of maximum height when the gun fires vertically up.
