1100 Tactical reliability: 18" vs. 22"?

Both. As far as I can tell, barrel length makes no difference in reliability. More important is a properly sized gas port, quality action springs, and regular replacement of the O-ring.

- Chris

+1 to what Chris said. A gas-operated shotgun will work with any length barrel, as long as the gas ports are kept clean and the shooter knows enough not to fire from the hip.

Stick to 20"

FWIW: When I went to have a barrel for my 1100 shortened for HD use my gunsmith recommended not going shorter than 20". He acknowledged that 18'' might work, and if not the gas port could be sized to get the proper pressure balance.

For me, neither of the two possibilities sounded great:

My trial and error reliability testing-and having to repeatedly return the
1100 to the 'smith until the adjustment was right.

OR paying the 'smith for testing trials until he found what worked.

I opted to go with the failsafe 20" length and it's been working perfectly at this length for over a year.