No published sn data. You will have to call the factory.
$200-$250, depending on condition.
The one issue with 5.56 in a handi rifle is the harder primers. You will almost absolutely have to install a heavier hammer spring. I have some Malaysian 5.56 and it often won't fire in the handi. I have heard the same about the Rossi single shots. As far as your concerns about pressures, the Handi handles all sorts of calibers on the same frame and barrel blank. Many of those push 65k or so. I don't worry about any difference in 223/556.
Well- sort of. Single shot top break rifles, such as the H&R Handi Rifle or the Thompson Center can change barrels, and can shoot several different cartridges- but not from one barrel.
A rifle with a 5.56x45 chamber can utilise .223 Remington cartridges. A rifle with a dedicated .223 Remington chamber cannot accommodate 5.56x45 cartridges. A rifle with a .223 Wylde chamber can accommodate .223 Wylde, .223 Remington, and 5.56x45, but neither a rifle with a 5.56x45 or a .223 Remington chamber can accommodate the .223 Wylde cartridge.
it is a one in 12" rate of twist good for up to 55 gr. bullets may stabalize some 60 gr but heavier bullets may suffer in accuracy..... Turns out that ALL H&R/NEF .223 barrels made will be 1-9 twist starting in 2006. This is great news to those of us who want an inexpencive .223 rifle that can shoot heavy bullets.
.223 Remington can be cycled in a 5.56x45 rifle; 5.56x45 should not be cycled in a .223 Remington firearm.
no
Depends on how old it is. If its an older one its 1:12 and the newer ones are 1:9 or 1:12. All the Marlin made barrels are 1:9 Best bet is to check it yourself. If you do not know how, drop me a message on my message board here at Answers.com
NO the .223 is a totaly diffrent round than the .223 WSSM
The 223 is considered a Short Action rifle.
50-250 uSD
you can fire both 5.56 and .223 ammo in a rifle chambered in 5.56...but not the other way around! In a rifle marked .223, you should fire .223 ammo only