for a 13.7inch barrel AR HBAR or medium profile ?
what is the weight deference between the two ?
Medium contour is not strictly defined, so you’ll have to ask the manufacturer. If you look at MOS-Tek’s website, there is approximately 3oz between most of the contour increments. So, somewhere around 6-9 oz for a 13.7”.
You can also estimate this mathematically using the formula for volume and then plugging in the steel’s density, if the maker publishes a drawing.
You’ll also need to narrow down the purpose. If I were a bench shooter, I’d choose HBAR every time. But I’m not, so I gravitate toward more moderate contours. My 13.5” is an Alpha profile, which MOS-Tek calls light/medium, I think. If I were doing it over, I’d go up a couple notches into medium territory, but I like it enough that I’ll wait until it’s roached. Mine’s an action-match gun, so high rates of fire over short periods with sprinting between strings. Some mass is beneficial for this, but HBAR would be over the top.
thanks, i’m think that the HBAR was designed for full auto fire , however if its only 3-4 oz more then a typical medium profile, it might be worth it