Leupold CDS/ Muzzle velocity?

[Confederate marksman]

Hey guys,

I just bought a Leupold CDS for my .308,

Obviously Leupold will need the muzzle velocity of my 165 gr. Nosler Accubond to engrave my elevation turret, along with the other particulars about my setup to get as accurate of a calculation as they can. My question is do I really need to buy a chronograph to get my muzzle velocity? Or can I use the velocity provided on the box of ammo?

Take into consideration that I only plan on taking shots up to 500yds with this rifle. As far as Im concerned, if I can hit a 8inch circle at 500yds that will be plenty good for what I plan on doing with the rifle.

 

[sveltri]

I think at a minimum you'd want to verify the drops that are specified on the box are accurate.

 

[The Oregonian]

The numbers on the box can be very wrong and are generic. What I would do is figure out your drop to 500 and validate at other distances that to determine velocity and drops.

Leaving the turret as it is will give you more flexibility.

Speed difference between reality and what's on the box

Hi, Today I was helping a friend shooting his factory Remington 700 xrc in 7rem mag at 900 yards. He was using factory hornady precision hunter ammunitions. That ammo is supposed to have a velocity of about 2940fps . We chronographed it at 2766fps. When running that speed through Balistic AE we...

www.longrangehunting.com

 

[Confederate marksman]

I think at a minimum you'd want to verify the drops that are specified on the box are accurate.

Thank you!

 

[Confederate marksman]

The numbers on the box can be very wrong and are generic. What I would do is figure out your drop to 500 and validate at other distances that to determine velocity and drops.

Leaving the turret as it is will give you more flexibility.

Speed difference between reality and what's on the box

Hi, Today I was helping a friend shooting his factory Remington 700 xrc in 7rem mag at 900 yards. He was using factory hornady precision hunter ammunitions. That ammo is supposed to have a velocity of about 2940fps . We chronographed it at 2766fps. When running that speed through Balistic AE we...

www.longrangehunting.com

Thank you!

 

[cohunt]

You could see if someone has one you could borrow.

A guess from the box will probably work out to 3-400 yards but 500 stars to push it.

You'd be better off just shooting to find your drops and record them--- those turrets are only good for 1bullet, 1 speed, 1 set of weather_altitude data etc. If things change then the cds dials can be off.

 

[whatnext]

You paid for the CDS dial you might as well verify your drops and order it. Use an app like "Shooter" and solve for velocity backwards at the longest range you can shoot. Research "truing muzzle velocity". Use the elevation and temperature you mostly hunt or an average if you hunt multiple locations. To 500 yards the error will be negligible and well within your 8" requirement. If your needs change, you can always put the original dial back on.

 

[Deleted member 115360]

You can zero at 100y, then build your data into a shooting ap. You can then move out to a 300y target, (this is just an example), and dial to the prescribed moa or mils given by your app.

Then you can mark your poi, and if it is high or low, adjust the m.v. data that you entered and the corresponding adjustment on your optic until you are hitting center at the longer range. That will give you an m.v. that will be way close enough for what you want. If you have a 500y range, you can use it at 500y for the same process, and you will have a darn accurate m.v. value.

In fact, done right it will probably give you a more accurate m.v. value than a cheap chronograph.

 

[Justice1327]

What others have said. I had 6 CDS dials done before I got a LabRdr. set it dead nuts at 100, shoot 200, measure drop, same all the way to 500. You can the use an app to calculate your muzzle velocity.Also, Leupold can take your drop info and decipher the velocity. Works well, but when environmentals change and or pwdr/primer/bullets change it can be off. Just be sure to know your drops and you can change to the correct MOA NEEDED

 

[jweigel]

If your shooting/hunting is mostly at the same elevation, same time of the year (temps) and generally less then 600 yards....a yardage turret will work fine. But if shoot a variety of places and times of the year or just important!!! other bullets....consider adopting to MOA or MIL. You will need to range the shot no matter the turret. Many range finders can upload the drops and output the MOA or MIL to dial. Also....having an understanding of MOA at various distances really helps when holding for wind.

You don't need a chrono to determine velocity. Use the box speed. Get 100 zero spot on. Use a App on your PC or Phone to calculate the drops for your shoot conditions and shoot as far as you have a good target and rest. If you shoot high....your speed is faster. If you shoot low, the speed is slower then the box. Many apps will have built in "speed calculator" to tweak the velocity to match the drops.

Whatever you do.....repeat it several times to get repeatability.

jjw
ND