Density altitude and sight tapes

[sickles107]

For those that have been following shoot 2 hunt / form, they talked about using density altitude as the only variable for air density in a ballistic calculator. I have been using this the past year or so with good success with a rifle.

Has anyone used this same concept for archery sight tapes? I don't have much experience shooting at differnt altitudes. Been shooting all summer at 5k elevation, ~75 degrees, ends up around 7kDA , comfortable with broad heads at 80.

Heading to Alaska this fall, right around sea level, depending on temps could be near 0 DA. I plan on buying a cheap atchery target when I land, though trying to get an idea how off my sight tape could be at 80.

 

[longrange13]

This is off topic from archery, but what apps do you use with density altitude? I’m trying to figure out how to use DA, I don’t see it as an option in most ballistic apps.

 

[ndfb35]

Precision Cut Archery is what folks seem to using now a days. I live and shoot around 2000' and shooting at between 6000 and 7000 I have no issues with that tape. If I go to 9000' then the tape ends up being hot and adjustments need to be made.

 

[Marble]

This is off topic from archery, but what apps do you use with density altitude? I’m trying to figure out how to use DA, I don’t see it as an option in most ballistic apps.

You can just Google density altitude and find solutions for it. I use it for racing. Temperature, pressure and water vapor all get together to create it.

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[Marble]

This is off topic from archery, but what apps do you use with density altitude? I’m trying to figure out how to use DA, I don’t see it as an option in most ballistic apps.

All you'll need to do is shoot your bow when you get there. If there is a change, it will be minor. Generally, it's an inch or 2, up or down, depending on the change in weather or altitude.

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[Nine Banger]

This is off topic from archery, but what apps do you use with density altitude? I’m trying to figure out how to use DA, I don’t see it as an option in most ballistic apps.

Shooter Ballistics App

 

[TheColorCamo]

I sighted in in western WA, at 400’ elevation, then moved to ID and at 5000’ my sight take was hitting high. At 20 yards i was shooting 3” higher than in WA. Im shooting a 440 grn arrow at 290fps. Your vane configuration and drag will make a difference on how it responds to air density, so its hard to calculate that. You will need to just afjust your sight when you get there. You should be able to move your sight to where your 20 is hitting center again, then while keeping the sight in the right spot, move the pin indicator on your tape to match up with your 20 again… should still be pretty close.

 

[180ls1]

I sighted in in western WA, at 400’ elevation, then moved to ID and at 5000’ my sight take was hitting high. At 20 yards i was shooting 3” higher than in WA. Im shooting a 440 grn arrow at 290fps. Your vane configuration and drag will make a difference on how it responds to air density, so its hard to calculate that. You will need to just afjust your sight when you get there. You should be able to move your sight to where your 20 is hitting center again, then while keeping the sight in the right spot, move the pin indicator on your tape to match up with your 20 again… should still be pretty close.

Something else was off for it to shift 3" at 20.

 

[sickles107]

Something else was off for it to shift 3" at 20.

That's what i was thinking too. Regardless of DA, zero at 100 with a rifle and zero with a bow at 20 shouldn't change. It's only variance of air density causing more or less drag to change impact at distance, measurable at 500 with rifle or 80 with bow.

 

[jbelz]

Get marks whenever you change altitude significantly and go from there. A tape is only as good as your marks.

 

[180ls1]

That's what i was thinking too. Regardless of DA, zero at 100 with a rifle and zero with a bow at 20 shouldn't change. It's only variance of air density causing more or less drag to change impact at distance, measurable at 500 with rifle or 80 with bow.

Yeah, I think the increased drag from the broadhead approximately offsets the less drag of the thinner air. At least within normal range, like you referenced.

 

[doc holiday13]

I just bought Precision cut for the year. I'm doing up a new site tape this week and i'll do a "projected" tape for when I'm out west later this year.

I live at 250-300' elevation and 50-80% humidity and hunting out west I'll be between 5k and 8K at 0-5% humidity, so I'll see what the difference comes out to