Posted by EPARMORY on 3/27/2026 to
The Kriss Vector Mongoose FRT
1st things 1st, Thank you for ordering from E P Armory. We appreciate your going with us for your FRT needs.
The
Kriss vector to start off is an awesome weapon but a finicky one for
sure. They do have a break in period (350+ rounds) and can have issues
before even modifying the platform at all. You will need to do some work
on your weapon before even moving onto the installation of the MONGOOSE. We
are not trash talking just a FYI so those with the KRISS Vector
understand that the new weapon they bought are needing a break in like a
1911 your grandpappy had in NAM.
- Polishing the bolt lugs (ears) to a nice shiny finish
- Polishing Mongoose after fitting
- Polishing the action rail guides
- Thoroughly clean the weapon to ensure smooth action of the weapon with no hang up in charging the weapon. Kriss Vector from factory can be catchy to rack a round in. If you feel drag when charging your Vector you need to polish all the key contact parts.
After working the first set of polishing and cleaning you will be ready to move on to the next part of installing the MONGOOSE.
- Remove the lower half from the upper half of the Vector
- Remove any optics or iron sights
- Remove the top rail of the Kriss Vector by removing the front roll pin and allen screw (gen 1)
- Remove the top rail by sliding it off of the guide sliding it from stock to muzzle
- Remove the allen screws from fire control and remove the fire control group from the upper half
- Remove the trigger from the fire control group and remove the disconnect
- Install the mongoose and test fit for initial check
- Function check the new Mongoose with simple function check before reinstalling by hand (look for hangup)
- Remove the Mongoose and polish the parts making hangup if any. (hangups are normal)
- Polish the mongoose after fitting if it was needed. ( A polished mongoose is a happy mongoose)
- Reinstall the Mongoose and function check by hand again. If no hangups it is ready for install.
- Actuate the hammer and trigger to check function by pulling trigger and manually resetting the hammer.
- If all looks good move on, if not disassemble and more polishing. ( Kriss has small inconsistent areas the can cause hangups)
- Reassemble weapon and apply lubrication. ( We suggest high temp grease or transmission fluid ATF4)
Assemble the weapon and check the action by manually pulling the trigger and actuating the charging handle to feel for trigger reset pressure. If you feel reset and the action is good move onto the next part. If you feel tension still you may need to go back to the polishing part and restart.
Test Fire!!
- Start with one round in the magazine and test fire to check locking back of the bolt. If it does not you have a drag issue still and go back to polish.
- 2nd test fire- 2 round in the magazine and see if she runs for you. If not go back to polishing and start over.
- 3rd test fire- 3 rounds in the magazine and see if she runs for you. If not go back to polish, check your lubrication and retest.
- 4th test fire- Load the magazine and crush all those watching the Kriss Vector run like it should for all Americans.
ENJOY YOUR MONGOOSE AND LET US KNOW HOW ELSE WE CAN HELP OR WHATEVER ELSE YOU WANT TO GO FAST.
(If you are having problems with your MONGOOSE call customer service before making the below processes)
:Below
photo shows the areas that can hangup but fitment needs to be confirmed before polishing. Polishing can be done by hand, tooling, tumbling in a case tumbler.
