DOES ANYONE KNOW STUFF ABOUT GUNS (OR BASEBALL BATS)?

As far as baseball bats are concerned, there are typically two varieties: Wooden and Metal.

Wooden bats are actually somewhat uncommon in league games (at least from my past experience of playing little league baseball in my youth) because they break easily, but I think they are lighter compared to their more standard counterpart: metal bats.

That's an idea you can work into your game. Assuming if you want equipment to break, you can have a wooden bat weapon that hits faster (maybe by increasing or not changing the AGI values of your characters), but has a relatively short lifespan, versus metal bats which would hit harder and last longer, but have a negative cost in attack speed.

As for your gun questions, you'd definitely have to ask someone else, but with what little I do know about them...

1) In the real world, yes there are guns that are far better than others. Keep in mind, however, that some of the tropes with video game guns exist for a reason. A shotgun in real life, for instance, is incredibly overpowered compared to other handguns, because the the whole "more damage the closer you are to a target" thing is actually a huge myth, and as long as you get hit (which these guns are designed to cover wide areas) you are still going to suffer serious injuries.

2) I'm not entirely sure on this, but I think there are some bullet types that are incompatible with some guns, while other bullet types are compatible with a broad range of guns. That's something you 'ought to research.

Maybe instead of getting new guns, you buy/find new "parts" for it to make it have stronger stopping power, or better aim (meaning you hit the intended body part you're aiming at, therefore doing more damage).

So you could have "weapons" simply be stuff like "Hollow grip (makes pistol lighter and easier to aim)", "Caliber converter (bigger bullets?)" and "Laser Sight (more aim, and thus more damage).

I did that for one of my games, where the gun user had the same gun the whole game, but you found "gearboxes" that acted as the "swappable" weapon that would alter the firepower of the gun.

As for the ammo types, there's enough suspension of disbelief going on already that it doesn't matter that guns take different caliber bullets. It just overcomplicates things.

As for the bat, More balance, sturdier materials and stuff like wrapping barbed wire around the business end are all valid ways to make a bat do more damage.

hockey sticks have a greater range than baseball bats

bahleted

You can probably do a combination of real guns and bats with your own made up guns and bats.

I remember hearing one of my students talking in great detail about guns (which weirded me out). I asked him where he learned all of that and he said from Call of Duty. So maybe playing a Call of Duty game would help your research... (Oh damn, did I really just recommend a Call of Duty game‽ Welp guess I gotta tear up my gamer card lol)
For the record I have only play CoD once at a friends house it was okay.

probably because they are FPS games.

Max McGee is giving you good information so I'm just going to add to what he's saying rather than telling you something different.

I personally prefer revolvers because they don't jam and are much easier to maintain. Others will prefer automatics for reasons such as quick reload time and quick firing times (which both of these can apply to a revolver if you have any skill with one.). Starting with revolvers: depending on brand, the cylinder may have as low a capacity as four shots or as high as seven shots, with the most common cylinders being 5 and six shots. Different caliber revolvers not only have different size barrels but different size cylinders (this is important for speed loading). Just like automatics need different size magazines, revolvers need different size loaders. Speed loaders are simple plastic rings that hold bullets. To use them, simply insert the bullets down into the cylinder and twist the metal knob on the back of the speed loader. Speed loaders are actually represented in the original Resident Evil for the 45 magnum (there's no such bullet, by the way. 45 is either ACP or LC.).

Automatics: these have their own benefits. No matter how fast a revolver man is with a speed loader (we can reload pretty fast: 16 seconds last timing), he isn't going to be at the same speed as simply dropping the old magazine and popping the new one in. Problem is, automatics have a jam rate. This doesn't mean, "the gun will occasionally fail to discharge." This means, "We at the manufacturer expect this gun to fail once per so many rounds fired." To be clear, this is not a flaw in the design of the gun; it is an inconsistency in the manufacture of the ammunition. Yeah, there's at least one bad bullet per batch of ammo that the manufacture predicts will find its way into your gun (this doesn't happen with revolvers. Even the bad bullets shoot.). When they jam, the gun will not work until the chamber is cleared. Sometimes, you can just hit the chamber and the jammed round will fly out. Other times, it means sitting down at a table and taking the gun apart. Obviously, this is a terrible thing to happen in a firefight. Now, the auto can also shoot faster than a revolver, but the amount is negligible. 2.5 seconds to dump a six round mag versus 3 seconds to dump a revolver is not a significant difference. Autos can use any size magazine they want. There's no issue with using a mag that's longer than the grip, as long as it locks into place.

Onto ammunition.

As McGee said, certain rounds for certain guns. There are exceptions, though. For example, a 357 revolver will also chamber a 38 special (Note a 38 special won't chamber a 357). This is because the 357 was developed as a high pressure loading of the 38 special, so a 357 revolver will operate just fine with the smaller round. Another example is that the .223 will fire from a 5.56, though it doesn't work very well because they operate at different pressures (again, there are exceptions, such as the Saiga 5.56 which will fire a .223 with no problems). Most 45ACPs will also fire 45LC and 44mag. Generally speaking though, no, in a realistic situation, you're not going to be able to switch up bullets with any old gun.

Also, bullet shape is going to lend heavily to it's stopping power. It's the age old debate: which is better, penetration or stopping power? Most people prefer stopping power, because in many cases when adrenaline is high, your assailant isn't even going to feel the bullet if it has low stopping power (this is the real problem with 22 rounds, which have no stopping power at all), which means, he isn't going to stop until blood loss makes him stop. 22s are not man stoppers. The only reason gangbangers carry them is because they're cheap. These are designed for hunting small game. They have little real use in a handgun. For comparison, bb and pellet guns fire .177 rounds, just slightly smaller than a 22.

So, obviously, this illustrates that going bang and making bad guy stop is not as straight-forward as it seems. Even large calibers with high penetration have the same problem. So your gun enthusiast is going to prefer hollow points, most likely. These are a bullet that has been drilled out at the point, as the name implies. The edges are pointed so they have medium penetration, but because the middle is recessed, they mushroom on impact and fracture within the body. They virtually explode, and they leave a hole much larger than the bullet itself. Some hollow points are teflon filled for added viciousness. They're all brass jacketed so they all hit really hard. Some varieties are serrated...yeah, as if these bullets weren't nasty enough. Hollow points are nasty, vicious things, but for small calibers in a defense situation, they're necessary. Your enthusiast will definitely prefer them in .38 special, which has notoriously low penetration to begin with, and that's even if he chooses to use a 38 (hence the fact that someone thought it was necessary to rework the round into the 357. Fun fact: we were running a pawn shop at the turn of the century when a next door neighbor was robbed at gun point and my dad was caught in the crossfire and a 38 literally bounced off his shoulder. Seriously. He kept the bullet. He had a huge bruise going all over his shoulder where it hit. We thought it might have broken his shoulder, but it was working fine the next day.).

Accuracy: LighteningLord has seriously oversimplified accuracy. She's right about the shotgun accuracy, but that is for the smallest sizes. A 500 foot accuracy is a 9 round. She's literally talking about birdshot. Shotgun buckshot is 0 or larger. So anything 1 through 9 is birdshot, which 9 has an accuracy of 500 feet, and the largest 1 has an accuracy of 1000 feet, buckshot 0 and 00 have an accuracy of about 1900, and 1 0z. slugs will go 3700 feet while 410s will fire at 2800.

Accuracy in handguns is a bit different. Because of the type of round used, there's a number of factors that come into play. Whenever you see LC, that stands for Long Colt (there's actually no such thing as the "long Colt". All Colts are long. The term actually comes from other brands with different size barrels comparing their long barrels to the Colt). Length of barrel is a major contributing factor. The longer your barrel, the more accurate your shot is at long distance. Snub nose, or short barrels are only for use in close range as they have poor accuracy. Also, the rotation of the bullet is a factor. Gun barrels are cut into spiral grooves. These grooves cause the bullet to spin, allowing it to maintain its trajectory gyroscopically.

Gun weight...I don't know where this came from. Yeah, if you're using a freaking 357 Desert Eagle then you might have trouble holding it. It's a fucking hand cannon. It weighs 5 pounds. It won't take long to get tired holding it. The vast majority of handguns are very lightweight with very light trigger actions. Example, the EAA Windicator 357 weighs 25 oz., which is a pound and a half. The Ruger Blackhawk 45ACP is 36 oz. which is 2.25 lbs. Two pounds is going to be about your average. As for recoil, yes, this can be a problem for some people, but seriously, it's nothing people can't deal with. Yes, big calibers have high recoil and low calibers have low recoil. A gun enthusiast is going to know how to deal with this. As for possibly breaking the wielder's arms...I kind of doubt that...although if you aren't holding the gun right when you fire, you just might break your nose.

Silencers: oft reviled, greatly vilified by Hollywood, and it's all bullshit. Silencers are very rarely used in crime, and yes, while a silencer doesn't completely quiet a gun, it reduces the report significantly, and if you use it on on a barrel with an inbuilt silencer (Ruger 10/22 for example), then yes, it can silence completely so that all you can hear is the firing pin go click. Uses for silencers include, enhanced hearing protection (yes, guns really go bang, and it really is loud enough to damage hearing), enhanced stealth (you may not like hunting, but when you're doing it to feed your family, just see how useful this is), and improved situational awareness (your gun can drown out the sounds of possible attackers or anything else sneaking up on you.).

Finally, I do want to correct one thing. Clips and magazines are two different things. Clips are exactly what they sound like, a pin that holds the bullets together. A magazine is a container with with spring that actually feeds the bullets into the chamber.

author=Sated
I don't understand why CoD gets so much hate. Although the series is fairly repetitive, they're decent FPS games.

I was just being goofy.

People can like whatever game they want. It's all good.

LockeZ
Electrobat - Bat and taser, now united in holy matrimony

Hey, I can't knock it. This one was good enough to thrash a Dalek in 1989...

To the original point: If you're worrying about being realistic, you're going about this the wrong way. No one really expects guns to be 100% realistic in games. FPSs just fall to different tropes than RPGs. A lot of the minutia discussed here is really hard to abstract into RPG stats that are meaningful in any way (after all, we can abstract weight, but a heavier gun doesn't fire more slowly, and actually tends to be more accurate if you hold it right since there is less recoil, but then you have to have recoil as an issue, which is another deal). Most of my tabletop games tend to be modern in design, and trying to go into every bit of minutia of guns in your rules just leads to an unfun game.

The basic concept is that a gun will kill someone. Stopping power, caliber, all those things are basically variations on 'making them stop trying to kill me sooner', not 'kills them or doesn't'. Pretty much any handgun will kill a person if you shoot them in the chest, factors being only time and whether they feel like killing you back in the meantime (disregarding care given to them to help them recover). There are obviously exceptions (Hey there Teddy!) but they are not the norm.

Instead, if you want to abstract for a game and give a character a meaningful progression with a handgun, a gun-nut would likely stick to a similar style of gun no matter what. Realistically for preference, a guy is not going to swap handgun styles constantly just for a bit of difference, they're going to get really good with one kind (An example in literature is Ciaphas Cain, who keeps his trusty (comparatively) 'low power' laspistol over an upgraded hellgun variant, because he knows it'll bork his aim, and being accurate is far more important than any improvement in stopping power it would give him). So a good way to do progression is both parts and ammunition, basically having the character tinker with their weapon, customizing and changing things around, but still using the same base gun. You said it was futuristic, so obviously they could change ammunition to deal with different threats, and modifications to give different stat boosts (accuracy, speed, etc). Realistically, damage shouldn't go up with different ammunition, but fuckit, SMT does it, so why not you as well?