Mossberg 500 ATP action bars UK

[sco77w]

Hi,
I've recently bought the above mentioned shotgun but I can't remove the action bars. In videos I've seen they just slide out as the last step of field stripping, mine don't.
Is it something I'm doing wrong or are they made captive as part of the 2+1 conversion to comply with UK section 2 capacity restrictions?
TIA

 

[old mossy]

Sounds like you might have an older 500 with the old style mag tube.
If so you need to remove the mag tube first. The action slide comes off the rear of the tube.
Keep us posted.