10agw +10agw=7agw? need some big Banana's

I agree Doug - a psychological barrier for sure but that is why even at times when I have really, really, wanted to trim a few, I always retwisted and reinserted the wire bundle just to get those last one or two uncooperative strands in with the rest of the team. 
There should be no reason for the OP to trim at all as the connectors in the links I provided are mostly huge.  I do not know about the Furutech bananas the OP ended up with but the Furez connectors are solid copper and have very large openings.  The bananas on the ebay link I posted look exactly like those I have previously purchased from Furez and if you go to the ebay store you will also find a silver plated version.   The Furez bananas had a small red or black foam insert inside of the connector barrel to resist deformation and help maintain a tight connection.
I make power cords using six, 10 awg, vintage Western Electric wires (2 wires each to pos, neg, and ground) into a Furutech plug/iec - without cutting the wires.  That can be tedious, but on big amps the result is very nice....sort of like turbocharging the amplifier yet maintaining a nice tone.

mitch, I didn't even bother to look at the connectors; just having fun. :) 

quick follow up......things did NOT turn out well. got my Furutech banana terminal and tried to have them installed. no go. the wires did fit into the connector (barely) but would not allow for the screws to set far enough in for the sleeve to slide down/over. really bummed!!
my local shop ended up getting/installing some more AQ banana's that did fit/work (again, barely). so i now have new AQ 500 series plugs all around. 

ordered the Furutech's above based on the 5mm spec they advertised. according to my math, that shoulda worked. it didn't. with the various types/shapes of wires AZ use's in the Santori shotguns, it was impossible to get them bundled up tight enough to allow the screw to set properly.  spent almost $500 in total to replace all the terminals/12 total, including professional install..... on 10 year old cables,??!.   don't even know for sure i'm gonna like them with the new setup?.

starting off by comparing them to some new, comparatively simple pure copper bi-wire cables from Schmitt (10 agw). will move on from there depending on what i hear.

no one told me there would math involved when i got into this hobby!! =)

That is too bad.  The Douglas folks are pretty good so maybe ask if you can return the Furutech connectors.  The 5mm ID specification clearly should have worked with your 7 awg wire, which would have a diameter of only about 3.7mm based on an awg chart.  The maximum specified diameter should have allowed for the set screws to be inserted far enough for the barrel to slide over the assembly.  I have personally used the copper Furez connectors I recommended (same as on the ebay link) with two runs of Western Electric NOS 10 awg wires, also a total of 7 awg, but they do not have an outer barrel so the covering is just heat shrink.