7 posts • Page 1 of 1
- Silent But Deadly
- Posts: 1504
- Joined: Sat Dec 07, 2013 2:40 pm
- Location: Western slope Colorado
Of all factors, temp will have the most effect. What happens with altitude gain is that temp normally drops, so it’s misleading.Sharkbite wrote:Doesnt your altitude play a factor as well?FatAlbert wrote:This something that you need to factor in if loading and shooting SUBS. https://www.weather.gov/epz/wxcalc_speedofsound its all about the air temp.
Bottom line is that 1050 fps is good basic number to use, good to “0”. There are other reasons to go slower, but if you’re just trying to get rid of the crack, it works.
This is a pretty good explanation with formulas and explanations.
300 Blackout, not just for sub-sonics.
temp will have an effect on sound, and I have noticed in winter, there is also less humidity when the temperature is lower.
When those totally ignorant of firearms make laws, you end up with totally ignorant firearm laws.
Air temperature affects the density of air. Colder means thicker air, hotter means thinner air. Thick air, higher velocity for mach 1, thinner air, lower velocity for mach 1. Humidity also affects SOS, making air thicker or thinner, as does altitude. Higher humidity, thicker air, lower humidity, thinner air. Adiabatic lapse rate for temp is 2*F/1000 ft, meaning temp decreases 2*F for every thousand feet above sea level (ASL), which will affect air density making it thinner the higher you go, which will affect the SOS as well. There are lots of variables in speed of sound calculations, but the number of 1050 f/s is a good one for keeping everything subsonic in most conditions.