p no way to tell caliber from just the sn.
Impossible to answer.
10-150 usd
Condition is more important than serial number. That being said the earlier and better condition will be worth more.
Need to know caliber, condition, and what markings are on the top of the barrel rib. sales@countrygunsmith.net
Take it to a gunsmith.
only valuable if within a certain serial # range. Mine is a 5 digit number and worth less than $100
100 or so
Made by many different makers over the past 100 years
Online! Search Iver Johnson information; There are forums that have experts or links to answer any question you have. I have yet to find a single source for everything Iver Johnson...
The Benjamin 250 is one of three pistols that make up the 250 line of air guns. Here is how they break down: 250 is a .175 BB pistol 252 is a .22 caliber pellet pistol 257 is a .177 caliber pistol. The problem is finding .175 BB's today most all BB are .177 caliber. I've heard that BB are still .175 only the caliber of the barrel has moved up to .177 to accommodate pellets. I suggest you just try one.
NO.
what is the model???? does the cylinder swing out or does unit break open ????