My [Tombfinger] I use ingame to clap all available content. It absolutely wrecks, enemies see fireworks I see red crits.
You need to have Sentinel with the vigilante mods on it's weapon to get the Red Crits with this Build altho that should be common knowledge by now.

Also for some reason this website doesn't calculate my stats properly, because ingame i see different (better) stats. Look at the screenshots below.

If you have any questions about the weapon or the build feel free to contact me either ingame - Iwaylo (that's iwaylo not Lwaylo), or leave a message here.