I have a new author site that I want to make available from a domain that I had previously used Apache rewriting to bounce traffic to my Amazon site, [R=301,L], which I want
I resolved this by opening dev tools (F12), click "Network", then click the "Preserve log" checkbox, and make the request that results in the cached 301. Right-click the request that results in the 301 and click "clear browser cache". Try again and then 301 should no-longer be cached.
In either Chrome or Firefox, you can refresh the redirect by typing "view-source:redirect.yoursite.com" and hitting enter. Then, refresh that page. Now, that should force Chrome or Firefox to refresh the redirect.
The simplest solution to this is to open up F12 dev tools, check disable cache and then visit the place generating the 301 redirect. This should update to the newer version.
Go to chrome://net-internals and at the far right open the drop-down and choose "Clear Cache". As of version 48, this was the only thing that worked for me to clear a cached 301.
Update: Unfortunately, as of version 71 (Dec 2018) Google has removed the net-internals feature.
For example we have cached redirect from http://example.com to https://example.com
screenshot
The "view-source:"-solution does not work for me in Google Chrome; but using the developer tools and setting "disable cache" to true/checked in the Network-tab forces a re-evaluation. BTW: temporary circumvention can be achieved in an anonymous-session (Ctrl+Shift+N) or by adding some fake query-argument, like "?foo=bar", to the URL.