newman84 said:
Only difference is that on dad's inside the frame it does not have mod. 10-5 like yours does it just has the numbers I listed above.
S&W did not use model numbers for Hand Ejector (i.e. swing-out cylinder) revolvers until 1957. Before model numbering started, these revolvers were categorized by name. These names tend to stump folks unfamiliar with old S&W's because only two models- the .38 Regulation Police and the .357 Highway Patrolman- normally had the actual name inscribed anywhere on the gun. For other models, the name is usually determined by examining the gun's chambering combined with its other features; the name was printed on the box and owner's manual, but these items are typically long lost.
Despite the names, it's fairly common practice for S&W enthusiasts to refer to guns made after WWII but before 1957 as "pre-Models", e.g. pre-Model 10.
newman84 said:
I called Smith and Wesson today and gave them the serial number and the man told me it is a 1955-1956 probably 56 he said n frame model 20.
This gun is a
.38/44 Heavy Duty aka pre-Model 20.
These guns were originally designed to fire a special high-powered version of the .38 Special round marketed variably as the .38/44 (hence the name) or the .38 Special Hi-Speed. This ammo was largely withdrawn from the market after WWII, partially due to safety concerns given its tendency to blow apart older .38 Special revolvers, and partially for marketing reasons- S&W had discovered that buyers would happily pay a lot more for .357 Magnum revolvers that had the same basic capabilities and cost around the same amount to manufacture.
AFAIK the prewar .38/44 actually remains the all-time top-selling N frame model due to its adoption by several law enforcement agencies, but after WWII, its sales dropped off steeply due to declining availability of the special ammunition and increasing availability of less expensive and lighter .357 Magnum revolvers that were perceived as being superior. The postwar pre-Model 20 is quite a rare gun, and model-numbered examples are rarer still.
newman84 said:
...if that is the correct age, could it have come factory with nickel plating?
Yes, this was an option, and was reportedly popular with lawmen in hot and humid (read: rust-inducing) Southern climates.
newman84 said:
Would they have plated the trigger and hammer, as they are plated as well?
NO. On a factory nickel Smith, the hammer and trigger have color case finish, the ejector star and ejector rod are blued, and the cylinder pawls on the ejector star are natural metal. Nickel in these areas indicates a refinish. (As a footnote, the blue ejector rod finish often wears off with use, but this leaves natural metal that will have a slightly different appearance from the nickel parts.) Additionally, later nickel Smiths had a shallow capital letter "N" stamped on the cylinder face, but I've forgotten whether S&W applied this mark in the time period in question.
WORD OF WARNING: During the period when .38/44's were much cheaper than equivalent .357 Magnum guns (i.e. the 1950s and 1960s), it was fairly common practice to lengthen the chambers of a .38/44 to allow .357 Magnum ammo to be fired. Doing so is not categorically unsafe because (a) the guns are VERY strong and (b) most commercial .357Mag is not loaded to the full limits of the cartridge's capability. However, due to the rarity of this gun, I would consider it
unwise and inadvisable to fire .357 in it; the chances are fairly remote that you'll blow it apart, but a chance exists.