So far the biggest I've shot is the .460. I don't count the .50 BMG since it's tamed down.

Then athe old guy sits down, fires, reloads, and is ready again

Freedoms lost are seldom restored.

"A government big enough to give you everything you want, is big enough to take away everything you have" Thomas Jefferson

"Laws that forbid the carrying of arms . . . disarm only those who are neither inclined nor determined to commit crimes . . . Such laws make things worse for the assaulted and better for the assailants; they serve rather to encourage than to prevent homicides, for an unarmed man may be attacked with greater confidence than an armed man." Cesare Beccaria, 1767 (Later quoted by Thomas Jefferson)

I'd imagine that's more like firing a subgun where in you need to lean into it

You lean into it, putting most of your weight on the front, and you grip the hell out of the rifle, especially on the fore-end. Most of those people obviously have never been taught to shoot any rifle, much less a .577 T-Rex; that's why it goes flying out of their hands.

Sub-guns and small caliber rifles are best shot from a chest plant and compact stance. You don't need to put your weight into them, just hold on and give the gun a solid platform (use your upper body weight to your advantage).

all I've got to shoot is a few MP5's

largest caliber rifle I've gotten my hands on was...I might have shot a 7mm Mag at one point...next up would be a .30-06

The MP5 is still my favorite. I've shot a Reisling, UMP45, Thompson, Super V, P90, MAC 11 in 9mm, MP5, and the MP5K-PDW. Of all of them, the P90 and MP5 are the most controllable. The MP5K-PDW is less controllable due to the lowered weight and increased firing rate, it's kinda a buzz-saw like the MAC. The .45 cal. sub-guns are just bleh, too much movement, and generally punishing to shoot.

I wanna get my hands on a 10mm MP5 and see how that goes...

how was the Thompson?