It looks like the buffer is protruding out too far, which could result in interfering with the firing pin being hit with enough force to make the firing pin go forward and strike the primer.

If you push on the back of the firing pin so it goes flush with the back of the buffer or bolt, you will notice that it doesn't protrude out the front.  The 1100/11-87 firing pin design is what Remington has referred to an inertia firing pin.  What this means is the firing has to be hit with enough force from the hammer striking it, that the firing pin goes past flush on the back of the bolt body, and continues forward enough to strike and ignite the primer.

So if the buffer is protruding too far out the rear, it could hinder the firing pin from going forward with enough force to get reliable ignition on the ammunition.  

Here is a pic of what it should look like.


Maybe try removing the buffer, flipping it around and see if it goes flush, as it does have a beveled edge on one end and flat square edge on the end.




CY6
Greg Sullivan "Sully"
SLR15 Rifles
DefensiveEdge.com
(763) 712-0123