Express Gun Oil by Parker Hale - it has been around for ages, just like me which is probably why I still use the stuff.
They say: A light mineral oil for moving parts of guns, rifles or pistols. Contains a special rust inhibitor.
There is not a lot more to say really, use it for cleaning your rifle or shotgun. Also ideal for use it for a wipe over and rust prevention. Add it to your order for a cleaning rod guide and you can include it in the postage charge.
It comes in a proper tin can with a proper spout and should last you for ages. 4.4fl oz/125ml