OP wrote:

Now, how many connections (wire nuts) can you put in a standard 4x4
box? I'm sure it is less than what I would need to get six outlets and
a feed line connected together.

GIYF:
http://www.hubbellcatalog.com/raco/R...?FAM=RacoBoxes

Summary for metal boxes:

A 2 1/8" deep 4" square can take 13 '12 AWG' or 15 '14 AWG'.
A 1 1/2" deep 4" square can take 9 '12 AWG' or 10 '14 AWG'.

A 2 1/8" deep 4 11/16" square can take 18 '12 AWG' or 21 '14 AWG'.

Those who prefer plastic can refer to the molded numbers on the box
and divide by 2.25 for 12 AWG or 2.00 for 14 AWG. You heathens.

I put the wire sizes in single quotes because of the following:

You must allow 1 'conductor' for all grounds together, and 2
'conductors'
for each yoked device (duplex outlet, light switch, double light switch
on one yoke,
Despard device )

To join 7 runs of 12-2 cable:

14 allowances - 7 x 2 conductors
1 allowance - all grounds together
No devices (junction box)

Total of 15 allowances. You will need a 4 11/16" square box, 2 1/8"
deep.

4 11/16" square boxes are man's best friend (but so are ceiling pans in
other
circumstances. :-) )

I'd actually prefer not to join so many wires in one box, and usually
try to have
4 or 5 cables at most.

Cordially yours:
A. P. M. F.