Badger Ordnance makes them for the Rem 700.
From their website:
Badger Ordnance | Premium Firearms Accessories
M16 Style Extractor
This simple but effective design works just like the extractor in an M16 rifle. Will not pull out like other extractors if a sticky cartridge is encountered. Used by the Naval Surface Warfare Center in Mk 13 sniper rifles. Made from Pre-hardened 4142 steel. Gunsmith installation required.
P/N 306-91 Magnum calibers
P/N 306-92 Lapua/Rigby based calibers
Wayne aka WAMBO