My Outdoor faucet still leaking after repair - Mansfield 500

[NHTerrys]

I had leaky outdoor spigot - removed stem and matched exactly to same style Mansfield 500 and got new rebuild kit as well. This is older style with right hand thread. Changed stem out and put on new washer and graphite packing sized for this - smaller size graphite piece on this older style - new packing nut as well. New faucet handle and screw was put on. I turn it on and runs fine no leaked when I hooked up garden hose it spews water out the end - ?