They are also known as the black truss markings. They provide a quick visual for the tape user and speed up the measuring process. Originally, 19.2 inches was used in metric layouts. Dividing 5 into 96 inches (8 feet) gives 19.2 inches, which yields five trusses per sheet. The black arrow in the photo to the right points directly at the black diamond located on 19.2. The red stud markings every 16 inches allow for a standard layout of six studs per 8-foot (96) section.
1 Minors under 18 must be accompanied by an adult at all times in the range and store. 2  You must be 21 years old to shoot a handgun & 18 years old to shoot a long gun without being accompanied by a parent or legal guardian.
It is accepted that if you do your job and put the bullet where it counts, you can count on the .308 to do its job and incapacitate the target. The US Army preaches an 800 meter maximum effective range for the .308, the USMC preaches a 1000 yard (915 meter) max effective range.hile we have made hits at 1000+ meters with the .308, we tend to agree with the Army and indicate that 800 meters is about the max limit for RELIABLE hits in all but extreme weather conditions.