Frank. What is the difference between a real Whitworth and a Mark X since they are both Yugo actions? Not being a wise guy because I have both but see no difference other than markings. Thanks...Bill.
Sorry about the slow response.
I consider those rifle built by the Whitworth Rifle Company to be the true Whitworth Rifles. They were assembled and proofed in England and some made their way to the US. After the assembly and sales distribution was transferred to Virginia the assembly changed slightly to ensure profitability and less hand assembly, polishing, soldering and quality stockwork became the standard. Some of the Mark X's I have were indeed assembled and proofed in England before import but they are few and far between.
The Mark X action is indeed the same as produced by Zastava but it is my understanding that the original manufactured parts and pieces were sold off and the later assembly was a matter of loose parts rather that the continuity of original manufacture. As the production grows larger the machinery and tooling are not as fine.
This is my opinion and conjecture as there is very little information about serial numbers and changes which took place. I only found one book with research in it. Check Bolt Action Rifles
By Frank De Haas, Wayne Van Zwoll
