It's a magazine tube under the barrel, turn the serrated near the muzzle until the opening shows and feed ammunition face forward. It's a bit scary that your asking this you might want to visit a gun shop to have them show you and ask about some basic firearms safety.
remington 740 fieldmaster . 30-06 caliber rifle
The RemingtonModel 121 fieldmaster was introduce in 1936 and discontinued in 1954
Request an owner's manual from Remington on their web site, it's free.
50-150 usd
You can request an owner's manual for free at Remington's web site. 10
it is below the feildmaster logo
All Remingtons made from 1921 have a date code stamped on the barrel. The details and table can be found on the Remington Society of America, Manufactures Link.
go to Remington web site they can help you as they did with my 870 wingmaster
The Remington Model 572 Fieldmaster slide action .22 caliber rifle was made from 1955 until 1988. The receiver on your rifle was made in 1980 but may not have been assembled into a rifle until 1981 or 82.
Check date code, see related links
Check the barrel codes on the Remington Society of America. http://remingtonsociety.com/rsa/questions/barrelcodes
It's date code stamped on the barrel, see related links for information on the Remington Society of America.