This is a .303 British round:
It's 150 grains in weight, and comes out of the muzzle at 2,770 feet per second, or roughly Mach 2.4. Originally introduced in the black powder era, it still sees civilian and some military use to this day.
From the other side of history's fence is this round:
It's the 8x57mm Mauser. It sends a 181 grain bullet out the muzzle at 2,700 feet per second. It too it still sees civilian and some military use to this day.
Both these cartridges are suitable for most big game hunting in the United States. Rifles are comparatively inexpensive, and their commercial ammunition was among the last to dry up during recent panics as the individuals most susceptible to said manipulations generally concentrate on 5.56 and 7.62mm NATO rounds. Ammunition prices are what you'd expect for a ".30 caliber" centerfire cartridge, but can be found on the lower side if one looks around.
An acquaintance of the author recently found a gently used Lee Enfield No.4 MkI rifle that had been lightly sporterized for the grand sum of $150, private sale. He reported that boxer-primed reloadable 180 grain softpoint ammo can be found at $18 for a box of 20. For just under $300 he now has a good .30 caliber rifle and 160 rounds of ammo.
What did that get him? A start. He now can hunt and defend himself.
He later came across this piece, also via private sale, for a similar price.
It's just an old police issue .38 Special Smith and Wesson Model 10. I'm certain thousands of these are sitting in gun store safes collecting dust. No one wants them, unless the person is a S&W collector. And even then, these revolvers are nothing special from a collector's standpoint, unless there is something distinguishing one from a stock model. Now he has something he can carry on his person for protection.
There is nothing special about these two firearms, yet they are still important tools for their owner because they serve the functions of food procurement and self-defense.
If you're not into collecting guns, and are looking for a working tool, don't get hung up on getting this or that specific thing. Figure out what you need to do, see what's available at a price you can afford, and get it provided it's in good working condition and it's something you can work with.