Expect maybe 4,100 fps and crappy accuracy.

The 17 Remington case is pretty much a 223 necked down.

Now shoot a 17 sabot in a 220 swft or 6-284 and you might break 5,000 fps. But accuracy will still suck.

I have shot 15 and 17 gn bullets in my 17 Mach IV (221 Fireball necked down to 17) and broke 4,000 fps and managed to explode prarie dogs out to 250 or so.