R 408.13874 Power levels.

Rule 3874. (1) The power level for cased or caseless loads shall be identified by a color and numbering system as prescribed in table 2, except that caseless loads are limited to power levels 1 to 6. The combination of the case color and load color shall designate the load level. Both the explosive load and the carton or box shall provide visual indication of the load level. (2) Studs or other fasteners used in a powder-actuated tool shall be only those specifically manufactured for use in such tools. (3) Table 2 reads as follows: TABLE 2 Nominal Power Case Color Load Color Velocity Level (+,- 45 fps) 1 Brass Gray 300 2 Brass Brown 390 3 Brass Green 480 4 Brass Yellow 570 5 Brass Red 660 6 Brass Purple 750 7 Nickel Gray 840 8 Nickel Brown 930 9 Nickel Green 1020 10 Nickel Yellow 1110 11 Nickel Red 1200 12 Nickel Purple 1290 Note: The nominal velocity applies to 3/8-inch diameter 350-grain ballistic slug fired in a test device and has no reference to actual velocity developed in any specific size or type of tool.