The longest I could find was a 670 mm from EdGI (not compatible with stock hop-ups though). In fact, I couldn't find any barrel that long, even non tight bore.
74cm = 740mm (there are 10 millimeters per centimeter).
This could help you decide for your baby blankets measurement 740mm x 890mm (29 x 35inches)
There are 1000mm in a metre. When converting mm to metre you muct divide by 1000. 740mm/1000 is 0.74 metres.
*awkward silence* 74cm .....
0.03937 inches is 1 mm 740x.03937 = 29.13 inch = 2 ft 5.13 inches = about 2ft - 5 and 1/8inch
To convert millimeters to inches, you can use the conversion factor of 1 inch being equal to 25.4 mm. Therefore, 740 mm is approximately 29.13 inches (740 mm ÷ 25.4 mm/inch ≈ 29.13 inches).
Using the ideal gas law formula (P1/T1 = P2/T2), we can solve for the new pressure. The initial pressure at 22 degrees Celsius is 740mm Hg and the initial temperature is 22 degrees Celsius. The new temperature is -22 degrees Celsius. Plugging these values into the formula, the new pressure is approximately 463 mm Hg.