Bought myself two new Spikes Tactical Punisher lowers the other day. Christmas present to me! So now I gotta figure out what to do with them. I currently have an 18" SPR (my version), 16" Tactical and a 16" Lightweight. All 5.56mm. Been looking at the Sharps 25-45 cartridge, using a 20" Black Hole Weaponry barrel for one. Then just totally blinging out the other and sticking with 5.56mm (no real reason for the bling other then, it can be done). What has attracted me to the 25-45, very little case prep, to accommodate the larger 87gr bullets. Anyone have any experience with the cartridge? I'm also open to suggestions that anyone might have?