Garand is awesome... and you gotta be a real man to do battle with one, a real candidate..
AK ranks high... but too many beachaz use it... and trajectory is a little... Limp. (Heck I love them,... but not manliest, despite rugged design and build and being maintenance free, like myself =))
M16... lol, mouse gun for dorks, nerds, paid off budget committees, and ladies... only good for head shots. It takes more than capacity and $$ to be a manly firearm... (got a few, but simply not manly, and requires way too much primping and prep before a night out on the town)
BAR- pretty cool, lots of grunt.. but the best ones are hard to get, and newer ones, while awesome, are light weight compromised hunters.. a little too fragile imo..
K98. Great rifle, but too glossy and not American.. so its out on the manly factor..
1911. Big time mans gun.. battle proven.. good to go in GI/MilSpec, not in tacticool pretty range spec that will choke on grains of sand. But manliest... a long gun will beat out the pistol every time...
Python... sick dirty harry power... but he shot wadcutters and low grain to be more accurate and less powerful... not manly at all. And in battle standards, the modern pistol (glock 20 in 10mm for example) makes this thing look under-gunned every time...
870... Whoa Daddy. MY VOTE!!! I have had every semi mass produced, and most all pumps, and my 870 is my go-to for all. If i can bust 3 clays from 100+' flying away at 35mph+ at the same time... I can sure dang well hit folks while me or them are on the move... The knock down power you need, slugs to destroy at range (and kill those wearing a vest, without even penetrating the vest.. simply pushes ribs into the lungs/heart, etc)... This is the bomb diggidy platform, from simplicity, to tac'ed out brawler entry gun..