Looks like you've got your Tac problem solved. That just leaves your question about speeds from a Ruger Compact. I've had 2 of these rifles. One in .243 that I sold and another in .223, which I still have and is my primary .223 rifle.
I don't recall ever testing any 50+ grain bullets for velocity, but when shooting Winchester USA 45 gr. HP's that were rated for 3,600 fps, I was getting around 3,300 or maybe a bit less. Most of my shooting has been with 40 gr. Vmaxes and 748 and AA2200C and AA2230C. Max loads have ranged from 3,275 with 748 to 3,350 with AA2200C.
To boil it down, I saw a drop of about 250-300 fps from book listed velocities. The .243 showed similar velocity loss with a load that usually clocked 3,200 from my 22" barreled rifle coming in at only 2900+ from the compact and 100 gr. Remington ammo that gave 2,900 from a 22" barrel only getting 2,600+ from the compact.
