Anti-tank rifles were very quickly made mostly irrelevent as tank armor increased in thickness. Projectile based anti-tank rifles struggled to penetrate the thicker armor, so anti-tank measures switched over to explosive based, such as rocket launchers, or vehicle based, such as large anti-tank cannons that must be moved around by vehicles or livestock.

The age of the hand held anti-tank gun was very short, but we get some awesome footage from it.

20mm Anti-Tank Gun vs Steel Plates in Ultra Slow Motion

The source part of that image can be found at about 4 min 15 seconds in the following video.

FullMag is an excellent YouTube channel with some amazing slow motion footage. The FullMag popular videos are fun ones to binge watch if you have some time to kill.