This weekend I was target practicing on some private land in North Dakota. We were shooting pop cans filled with water at various distances between 150 to 300 yards. (yes with a safe background) As expected, when the pop cans were hit they exploded into several pieces. No surprise.

What I found very interesting...was what happened when the 58 vmax hit a coffee can filled with water at 170 yards. The sides of the coffee can peeled away from about half of the bottom of the can, but there was no exit hole. I found a lot of the copper jacket (in small fragments)in the bottom of the can with a slight thumb size dent on the far side of the can.

Anyway, it just amazed me that my lowly airgun with a muzzle velocity of 880 fps can penetrate both sides of a coffee can filled with water, yet my .243 with a muzzle velocity of 3,900 fps couldn't penetrate both sides. pc

Wait until you see what it does to a squirrel or rabbit!! AWSOME

My experience with the 58 grn .243 Vmax is that it does give explosive performance on ground squirrels from 100 to about 400 yards. All the carcasses that I look at are just about blown in half and jellified (is that a word?).
That explosive energy transfer is why it doesn't exit the coffee can, while the pellet doesn't expand or transfer much energy to the target, merely passing through it.

120 grain Sierra's out of my 7 mag will not penetrate the back side of a gallon milk jug at 100 yards. The whole jacket will be laying right where the jug was and when you put the jug back together rarely will it have a mark in the back side.

High velocity varmint bullets are designed to explode on impact at all practical hunting ranges. The copper jacket is a specific thickness with interior lines scribed in the copper jacket nose to open violently on impact and a special lead core compound used. The old cartridges like the 45-70 used to harvest Bison firing solid hard lead bullets weighing 465 grains at slow velocity. The key to their power was there shape and retained energy they maintained at extreme ranges. They lost forward momentum much slower due to their weight and shape. Much like the 220, 240, 260 long sleek .308 diameter bullets now used in those long range target rifles used today. It is called Sectional Density+Balistic co-efficient that determines how well a bullet will fly through the air and loose it's velocity much slower than a short fat light weight bullet.
Your slow moving hard lead pellet with it's special shape design has the ability to completely penetrate the filled coffe can due to its shape and denseity. Low velocity and the lead mix used to make the pellet involved even though it is only traveling at 880 fps. Being much closer to the target also has a bearing on the effect when the pellet stikes the target. How any projectile is contructed and tested for effect during firing will determine how it performs on any given target. Some Government ordenance pieces have the ability to penetrate over 30 feet through re-enforced concrete before it detonates.
Much like a bow shooting an arrow at 280 fps will pass completely through a deer and stick in the ground. It also would probably pass completely through the water filled coffee can at 40 yards and stick in the ground.
The laws of physics are the primary factors involved in any and all those statements made in my post.

High vel and light bullet constrution have always cause rapid expension. I very hard slower bullet well travel a long ways through stuff. But heres one for you a 60gr gold dot speer shot out of a 308 win. at 2600 fps well not make to through a water filled pop can. A close range rabbit out of the garden load that just mists them.