I only a single 15 pack and these are 300 grain. One thing that I will say is that the 300gr version is a longer bullet and has more bearing surface, which alone makes it load snugger than a 250gr Thor of the same size. One concern, will we lose some FPS due to the design? Taking a closer look at the bullet on the Right, this is the all new One size fits all Thor. How do they do that? This bullet is .503" diameter, but have 4 cuts, very thin, that run almost to the base of the bullet. The purpose is to allow the concave base of the bullet, to slightly crush inward as you push the bullet down the bore. We are basically sizing the Thor to OUR bore size, as we load! Bullet on the left is a standard Thor. With a standard 300gr Thor and 100gr Blackhorn209, I've clocked these bullets at 1,826 FPS. Will the New one size fits all Thor do the same, or will we lose some Velocity? I personally do not think we'll lose much at all, if any FPS due to the fact that the base that flares up the most upon ignition, is still whole, and will fatten up and seat the bore. We will take a look-see however! I did check a couple of my Traditions Sidelocks and believe it or not, I was able to start the bullet by hand before pulling it out as I do not intend to shoot them out of those rifles just yet. No word on when they will be 100% available or if they will offer them in the 250 grain version, but at least we have something to look forward to and simplify sizing them from now on.