Most guns have no problem penetrating steel, it’s really just the problem of penetrating thick steel walls. And in order for guns to have more penetration to pierce through thicker and stronger walls, the points have to be sharp, but also have a larger caliber. If your gun is stupidity large, then it either has to have and advantage of caliber size, capacity, recoil control or fire rate. In your case it is caliber size. With a stupidly large gun, you will stuggle to aim it and carry, let alone control the recoil. For example. The 50 caliber round can penetrate concrete walls, steel beams and entire vehicles. With that, 50 caliber rounds have the disadvantage of powerful recoil. The recoil of the M107 50 caliber sniper rifle can dislocate your shoulder. But it has one hell of a devastating shot that will blow limbs off with ease.

Doesn’t matter. The strongest of people will always struggle to control the recoil of the M4A1 despite how small the round is. Guns without recoil depends completly on how the are built and how good the user is at controlling recoil. People one hand guns all the time. I’ve seen people one hand the M60 light machine gun. Only drawback is how hard it is to aim.

No matter where you shoot. You will recieve recoil from the forces created withing the gun.

Yeah. Every weapon that exist has recoil. Some just have alot less than others. But the bigger the round, the more recoil you will recieve.

Upon impact with something hard they might. Guns lift up when being shot due to the explosion within the casing that propels the bullet. That small explosion is responsible for the muzzle flash and the lift in the gun when being shot (recoil)