The French RSC-1917 semiauto rifle was a major step forward in arms technology during World War One, offering a reliable and effective self-loading rifle for issue to squad leaders, expert marksmen, and other particularly experienced and effective troops. No other military was able to field a semiauto combat shoulder rifle during this was in anything but very limited numbers. However, the RSC-1917 definitely had some shortcomings:

- It was just too long, at the same size as the Lebel
- The specialized clip was a logistical problem
- The gas system was fragile and difficult to clean or disassemble
- The magazine cover was easily damaged

These issues were all addressed in the Model 1918 upgrade of the rifle, although it was too late to see active service in the Great War. The new pattern was substantially shorter (both the stock and barrel), it used the standard Berthier 5-round clip, it had a substantially strengthened magazine cover, and a much improved gas system.

Today, we will compare the various features of the 1917 and 1918 rifles, and disassemble the 1918 gas system to show how it worked. Special thanks to Paul for letting me use his rifles!