Summary.
To use a stock Nova as an example (not 18.5"), if it holds 3 shells in the fixed factory tube, and a +4 Nordic tube is installed, you will have a 8 shell capacity, 7 in the tube and 1 in the chamber.
Overall length of the tube extensions( including the nut):
+2 - 5 3/4 inches
+3 - 8 3/8 inches
+4 - 10 1/8 inches
by the way 79.99 and could possibly need a clamp not sure, but would look good with flashlight surefire out of the question(looks like wally world).
I found a place called briley.com that would add chokes to smooth TS Nova. But not going to gain anything that I can see.
Why would I or anyone need a heat shield ????
So now it's down to` the best HD cartridge, I know essay could be written on this. I still can't find any numbers comparing 2 3/4, 3 & 3 1/2 for velocity,force and drop off at 30 yards.
I think steel shot would have more penetration over traditional shot. Has anyone used the FS steel shot it sounds good?
So far I think 3 1/2 of number 2 steel shot will be the way I go. I did see some kind of dart projectiles you can buy but are probably illegal.
If I put on a pistol grip no butt stock is it still legal or do I need a folding?