In the early 1990s I got a great Bore-Store bag for large/med size 4-6" barrel handguns. It has a treated fabric that protects the firearm & it's easy to use(note; it is NOT secured) so it's not ideal for regular storage around kids or untrained adults.
See;
www.thesportsmansguide.com www.midwayusa.com www.brownells.com .
CF