Can't see from the photo, do you have gussets on the brackets underneath?
Every time I look at it, the barrel gets bigger and the band gets smaller.
I have been thinking about the "gusset" idea.
I don't see why they are needed.
Look at these pictures. Here is some more info on them.
The material of the collar is 3/8" X 7" wide.
The gap between the flange plates welded to the underneath side is 1".
The gap allows me a little wiggle room for lateral movement when fitting the collar.
The flange plates are 7" wide and will accept three 5/8" splice bolts.
I have an assortment of 3/8" and 1/4" spacers with the same three holes in them to put in between the flange plates as needed so I can tighten the 5/8" bolts really tight.
The flange plates can't bend in because of the spacers.
They can't bend out because three 5/8" bolts across 7" just won't allow it.
That's my reasoning anyway.
I believe the majority of the weight of the 2240 lb. barrel will be sitting on the leveling screw platform.
The collar has an open top.
The top horizontal line of the trunnions is equal to the height of the center line of the bore.
This is how below center trunnion guns were engineered.
Some of the collar extends above the center line of the bore. This actually captures the barrel preventing it from "jumping" out of the collar.
The spread of the top of the collar is less than the spread of the barrel at the center line of the bore.
Anyone see any holes in this?