Winchester created their version of the A5 Sniper that they called the Marine Mount in April/May 1917. They did not have a 7.2'' spacing blocks for the M1903 prior to that date. There are pics of a 2 test pattern rifles and one complete 03 rifle with their 7.2'' spacing Marine Mount in the WRA files.
The serials of these rifles in the Winchester WWI files are:
34215
367312
659062
My rifle is 368496. It is a little over a 1000 digits from the rifle pictured in the WWI Winchester files.
My rifle was built in 1909, the most famous pic of a Winchester Marine mount A5 taken in 1917 in France is also a pre-1910 rifle. You can tell by the traits of the rifle.
There are 2 pictures of this rifle taken in France in 1917.
I made a high definition copy of the original glass slide so I could really tell the details of the rifle. It is a pre 1910 rifle by the traits, as is mine.
My 1909 rifle vs the pre 1910 rifle taken in France.
My rifle compared to serial 659062 in the WWI Winchester files.
There are also more of these rifles that fall into the serial ranges you believe are exclusive to Mann Nienders. These are in a very advanced Sniper Collectors hands, and I will not name him. But these are in the 672,xxx and 678,xxx serial ranges. These rifles are identical to mine, and also the pics of the rifles in the WWI Winchester files.
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