The 204 Ruger is actually a rifle cartridge, therefore does not come with any accessories. It is primarily intended for use with Ruger's Varmint rifle.
Ruger 10 22 accessories can be bought at your gun shops, local department stores such as Walmart, Target, AAFES, and the NEX, and Ruger accessories can also be found online at secure gun dealers.
CF
The .204 Ruger is a .222 Remington Magnum casing, necked down for a projectile of 5.2mm/.204 inches. When introduced in 2004, it was the highest velocity production cartridge in existence. There are AR-15 upper receivers available for it, among other platforms.
500 USD
Data from Hornady shows MV of 3625 to 4225 fps, depending on bullet weight.
Each has areas where they'd have advantages and disadvantages versus the other.
With a 32 grain V-Max bullet, the .204 Ruger has a muzzle velocity of about 4225 feet per second. Pretty quick.
100-1000 or so depending on EXACTLY what you have, condition, accessories, etc..
Ruger has extensive sn data on their website. Value will depend on condition, box, accessories, papers, etc..
100-400 USD depending on condition, accessories, box, manual, etc..
100-300 USD depending on condition, accessories, box, papers.
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