This may be more then you want to know about the X5 guns. Below is from a series of articles I did for the Ithaca GC newsletter in 2/99. The figures were lost when I converted the old file so I have edited out references to them.
The Historian's Corner
THE ITHACA X-5 LIGHTING
For the three generations prior to 1958, the Ithaca Gun Company had been a shotgun manufacturer. That long held tradition changed in 1958 with the announcement to the shooting world of a .22 caliber long rifle semi-automatic rifle named the Ithaca X-5 Lightning. The new gun, commonly referred to as the X-5C, was a clip fed rifle equipped with a 7 shot clip; a 10 shot clip was available as an accessory. (The company originally advertised the larger clip to have a 12 shot capacity, but in fact most would often only hold 11 bullets. Later advertising changed the claim to a 10 shot clip.) The retail price at introduction was $54.95.
The concept for the X-5C began some years prior to 1958. During 1955, Ithaca Gun contracted with the firm of Cabot and Webster to design a .22 caliber autoloader. Cabot and Webster was a New England based engineering consulting firm whose principles, Walter H. B. Smith and Joel Gross, specialized in applying the new manufacturing technology learned during WW2 to the firearms industry. Much of the design concept for the Ithaca X-5 Lightning was contributed by Joel Gross who made his first presentation of the gun to the Ithaca Gun Company board of Directors in 1956. To honor Joel Gross' contribution to the design and the manufacturing methods used in the model, Sheldon Smith presented him gun number 1A, the first X-5C Lightening Model produced. Gross later give the gun to the NRA Museum where it can be found today.
The serial number range of the X-5 Lighting started with 1A which was made during December, 1957 . Production ended during April, 1963 at approximately 19600A, being replaced by a new model, the X-15 Lighting..
Another .22 caliber rifle model, the X-5 Lighting Tubular (X-5T) was announced in 1959. This model, as the name implied, had a tubular magazine holding 16, .22 caliber long rifle cartridges. Unlike the finger grooves seen on the forend of the clip model, the X-5T had a beavertail style forend with no finger grooves. The design of the X-5T is believed to have been an internal Ithaca Gun engineering project. The introductory price of the X-5T was $54.95. It was reduced to $49.95 for the 1960 sales year where it remained throughout its production life.
A footnote to the December 15, 1960 Ithaca Distributor Price list stated that the X-5T, along with the X-5C, "... can be furnished with figured maple stocks in either light or medium color finish. Orders for maple stocks are limited to stock on hand." A scope was added to the X5T for a Christmas promotion in an attempt to boost sales. Unfortunately, a price reduction, the addition of a scope or the option of a curly maple stock did not provide adequate sales interest. The X-5T Lighting quietly left the Ithaca product offering at the close of the 1962 sales year.
Both the X-5C and the X-5T are numbered within the same serial number range. All of the X-5C serial numbers end with the letter A, all of the X-5T numbers end with the letter T.
It is unknown at this time exactly how many X-5C and X-5T rifles were built. Let me try the following analysis on you to approximate production. The earliest serial number noted to date for an X-5T is 12689T, an early gun sent to Southern Outdoors of Atlanta, Georgia on June 4, 1959. Considering that production of the first 4000 Tubular models was authorized only on May 5, of that year, perhaps the serial number range began within the 12000 range. The latest gun noted was serial number 18302T, a gun sent to The AOPA Pilot, Bethesda, Maryland on August 4, 1961. Since all X5 Lighting Models ended with serial number 19599, it is reasonable to expect to find X-5T models up to that range. Based upon the assumption that all 4,000 of the original factory order were made and sold and that at least half of a latter authorized 5,000 part sets were assembled and sold, I predict that approximately 6,500 X-5T Lighting models were produced. Having made a prediction of the production quantity of the X-5T, and assuming that a gun was made for each serial number which ended with 19,599, the deductive process suggests that approximately 13,100 X-5C models were produced.
Copyright 2/99
Walter C. Snyder