Range Report What effect would a 5k foot elevation change have on muzzle velocity?

[Long Range 338]

So I see somebody who lives at sea level who is getting ready to go hunting ask about muzzle velocity variance based on elevation changes. I understand the air is less dense at higher altitude and you could line up your ballistic chart to match the atmospherics or density altitude but if your muzzle velocity changed more than 25 fps you could be quite a ways off. Would this be a real concern?

 

[Supersubes]

No

 

[morganlamprecht]

from sea level in corpus christi to approx 4000+ feet in fort morgan, co....temps were similar and my velocity didnt change any

 

[CJS-6.5]

Muzzle velocity won't really change much. It's the velocity at distance that changes due to thinner air.

 

[mudpig]

what CJS said ^

 

[Milepost]

Sea level pressure ... 14.7 psi / in2 vs 60K Plus pressure?

I'd say any change in in altitude would not be negligible in muzzle velocity.

 

[Long Range 338]

So the ballistic calculator would adjust for this due to the atmospherics, correct?

 

[tna9001]

So the ballistic calculator would adjust for this due to the atmospherics, correct?

Yes, as long as you've updated the info.

 

[CJS-6.5]

Sea level pressure ... 14.7 psi / in2 vs 60K Plus pressure?

I'd say any change in in altitude would not be negligible in muzzle velocity.

Would not be? Care to explain?

 

[Lowlight]

Air Density changes need time for the effect to be visible.

So your Zero and MV will not change, your dope beyond 350 yards will change because distance means time for the air density to have an impact on the bullet's flight.

 

[Milepost]

Would not be? Care to explain?

Sorry... Negligible

A decrease of say 2 psi in altitude from sea level is so small compared to the 60K + psi pressures that any change in muzzle velocity would be negligible.

 

[CJS-6.5]

Sorry... Negligible

A decrease of say 2 psi in altitude from sea level is so small compared to the 60K + psi pressures that any change in muzzle velocity would be negligible.

? that's what I figured. Darn typos.

 

[CJS-6.5]

One thing that can happen as elevation goes up, is that temperatures usually drop at the higher elevations. Like 5000 plus. So if your powder is temp sensitive your muzzle velocity can drop. Always rezero and dope at different elevations.

 

[40xs]

A friend and I went to Kolorado a few years back and while there we shot prairie dogs for a couple of days. Our guns were sighted in for elevation in piedmont N.C. roughly 700-800 elevation. we were hunting at about 5k elevation. We had no chrono with us but all of our shots were going 3-4 inches over our targets. we had to adjust accordingly. I'm saying elevation will print your bullets higher.

 

[Lowlight]

Thinner air,

Your zero doesn’t change, and your MV May change depending on temperature.

But it’s distance, the thinner air is less resistance on the bullet, so it travels farther.