The model 303 came in .177 & .22 Cal production started in 1969 and discontinued in 1993. Unfortunately you did not state the condition of the rifle so no estimate of value can be given. Is it Excellent, Very Good, Good, Fair or Poor?
In good condition it is worth between $45-$85. More if it is in excellent condition.
600-700 USD
Depending on condition, barrel, and sights- $100-200.
Different values for steel frame vs aluminum, and adjustable sights vs fixed sights. ABOUT $200-$325, depending as always on exact model and condition.
Being that these are/were military rifles, any example in perfect condition would probably bring in 2K range.
$200-$400, depending on condition, finish, type of sights, etc.
What model number? What barrel length, What finish? What type of sights? What condition is it in?
Anywhere from $100-275, depending on condition, barrel, sights.
Fixed sights, adjustable sights, target sight, night sights, 3 dot sights, telescopic sights, red dot sighs, lasers, etc.
$100-$200, if you have an excellent condition rifle, complete with all sights.
Roughly $150-$300, depending on exact model and condition. There are different barrels, sights, etc.
$100-375, depending on model, barel, sights, condition, etc.