It's all in the caliber and fps.
The 620 is a 4.5mm or .177 caliber pellet rifle and is rated around 450 FPS.
The Chinese B-3 is rated at 450 FPS by the Manufacture. This is considered to be slow in the world of .22 caliber air rifles. As an example the Hatsan model 95 fires a .22 caliber pellet at 800 FPS and a Crosman Nitro Venom fires a .22 cal pellet at 950 FPS.
The Crosman 1322 fires a .22 caliber pellet. It is rated at 460 Feet Per Second (FPS).The Crosman 1322 fires a .22 caliber pellet. It is rated at 460 Feet Per Second (FPS).
The muzzle energy from a .45 caliber round can vary between 350 to a little over 500 ft-lbs, with velocites from about 850 feet per second to over 1000 FPS. The .40 caliber round can range from about 480 to about 570 ft-lbs of energy with velocities ranging from about 1000 FPS to about 1400 FPS. So, in short, it depends on the specifications of the particular cartridges you are comparing.
Impossible to answer without knowing the weight of the pellet and caliber.
You do mean pellet rifle, not pellet gun. The Phantom is a rifle. First of all not all Wallmarts carry the same air rifles in every store let alone every state. But I can help you with this information. The Phantom is a .177 caliber rifle that is rated at 1000 Feet Per Second (FPS) I suggest looking for a rifle that has a higher FPS ie: 1200 FPS or a .22 caliber rifle that shoots close to 1000 FPS. A .22 at 800 FPS will be a bit slower but it is a bigger pellet and will have more knock-down power than a .177 pellet at 1000 FPS. Don't confuse Speed with Power. Think of it this way. If I shot a 1/4 piece of plywood with a .177 pellet, I would make a very nice dent in it. If I shot the same piece of wood with a .22 caliber Pellet at 900 fps I would most likely make a hole most of the way through it. Why Because the .22 is a much heaver pellet.
no, a 45 caliber is way more powerful than a 40 caliber Actually, it depends. The following is copied from another answer of mine: The muzzle energy from a .45 caliber round can vary between 350 to a little over 500 ft-lbs, with velocites from about 850 feet per second to over 1000 FPS. The .40 caliber round can range from about 480 to about 570 ft-lbs of energy with velocities ranging from about 1000 FPS to about 1400 FPS. So, in short, it depends on the specifications of the particular cartridges you are comparing.
It could do it, although it wouldn't be the most "graceful" means of accomplishing it.
If you are talking about a .177 caliber pellet. Most likely the answer is NO. But if you are talking about a 45 caliber or 50 caliber pellet then the answer is Yes. Pellet guns come in .177, .20, .22, .25, 9MM, 45 cal and 50 Caliber. The last 3 sizes are fired by PCP air rifles (Recharged pneumatic ) that require a scuba tank to charge them to 3000 PSI. They are still pellet rifles just the BIG BOY of pellet rifles.
It's not so much the FPS, anything above 500 FPS is fine, it's the size of the pellet and knockdown power that you are looking for. Pellets come in different shapes. I would use a hollow point pellet. It's a cross between a flat and BB pellet. They are made by Gamo, I believe. Or I would not use 177 pellets for hunting but 20 or 22 caliber pellets. They are a bit slower in FPS than 177 but have greater knock down power and a cleaner kill. Remember the gun must be made for 20 or 22 caliber if this is what you want. I have shot rabbits with a 177 pointed pellet at 1000 FPS and it went right through him. He hopped away and died. The pellet didn't hit anything it just went through him.
600 FPS - Pellet 625 FPS - BB