M741 / m731 / m692 155-mm

[US-Subs]

My 8-inch sadarm sub (pic 1) has slots that look like it may be keyed to prevent spin, but it is hard to tell - could just be for spacers. My 155 sadarm (pic 2) has no such slots.

 

[HAZORD]

My dummy 8 inch SADARMs have the same groove in them. The 8 inch 509 projo has two grooves machined lengthwise, 180 degrees apart. As I said before, the 155mm SADARM projo is too thin to put a groove in.