Do I need +20MOA Base

[Curt]

Do I need increased MOA base for my .223 that I am going to shoot to 500yards or so. We don't have a range for any longer than that. I have a 8-32X40 Bushnell scope, which I believe has 20-25 MOA adjustment.

 

[Obtunded]

Probably not. your 20 MOA internal is about 104 inches at 500 yards.

 

[Curt]

What is going to be the bullet drop @ 500 yrds. 75gr amax pushed what, 2800-2900 fps muzzle velocity.

 

[BC_Guy]

Using the eskimo online calculator, a 75gr amax going 2900fps will drop 65.2inches by 500(meters). 51.5inches by 500(yards).

 

[gaetoune]

I personnally use Burris signature ZEE ring with offset insert. Really good mounts. The combination of inserts give you about 30 MOA total. Price About 60$ plus 13 for the inserts.

For your question, you probably don't need one. 500 yds is not that far, your scope shoud have enough elevation. If you want have precise ballistic, check for an external ballistic calculator.

Here's a link: http://www.biggameinfo.com/BalCalc.aspx
It actually give you clicks as well...

Type your info and Voila.

Cheers Gaetoune

 

[Curt]

That is a kicka$$ tool, thanks.

 

[Curt]

So what distance would I top out at without a +MOA base?

 

[Kodiak99317]

Not so much a question of were you'd top out at, as to how low can ya' go after adding the 20+ base. If your at zero at 100 now and at the bottom of the downward clicks, adding 20moa base makes your new zero 760 yds! And you'd have 25moa of scope ups from there, so about 1150 you'd be...

If you got 25moa in the scope and your at the bottom at 100 yds and at zero, your good to 800yds (22 moa up from 100yds) with a 80g SMK at 2900 fps.

Trajectory for Sierra Bullets .224 dia. 80 gr. HPBT MatchKing at 2900 Feet per Second
At an Elevation Angle of: 0 degrees, 100 yd zero
Ballistic Coefficients of: 0.42 0.4 0.393 0.393 0.393
Velocity Boundaries (Feet per Second) of: 2200 1800 1800 1800
Wind Direction is: 3.0 o'clock and a Wind Velocity of: 10.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0 Cross Range: 10.0 Vertical: 0.0
Altitude: 1704 Feet Humidity: 78 Percent Pressure: 29.53 in/Hg
Temperature: 59 F
Data Printed in English Units

Range Velocity Energy Momentum Drop Bullet Path Wind Drift Time of Flight
(Yards) (Ft/Sec) (Ft/Lbs) (Lb-Sec) (inches) (1 MoA) (1 MoA) (Seconds)

• 0 2900 1493.7 1.03 0.00 0.00 0.0 0.000000000
• 100 2693.3 1288.3 0.96 -2.17 0.00 0.7 0.107351699
• 200 2496.2 1106.6 0.89 -9.14 -1.58 1.4 0.223059829
• 300 2307.4 945.6 0.82 -21.70 -3.88 2.1 0.348069182
• 400 2123.2 800.6 0.75 -40.80 -6.59 2.9 0.483547692
• 500 1942.6 670.3 0.69 -67.64 -9.70 3.8 0.631277982
• 600 1771.4 557.3 0.63 -103.72 -13.24 4.8 0.793009683
• 700 1608.9 459.7 0.57 -150.90 -17.29 5.9 0.970775135
• 800 1459.7 378.4 0.52 -211.56 -21.93 7.1 1.166647469
• 900 1326.1 312.3 0.47 -288.58 -27.27 8.4 1.382465195
• 1000 1211.1 260.5 0.43 -385.41 -33.44 9.8 1.619512543
  Yds.^VEL.^ NRG.^MOM^IN DROP.DMOA.WMOA^TOF

You need 10 moa of wind on (9.8) at 1000 or 104" or 8.6 ft of wind....with this very good BC bullet and a 10 mph 3 oclock wind... and 33.44 moa of UP in total from 100 yd zero.

I do not think this will format right but ... too bad you can't just add an attachment eh...

 

[Curt]

So I should mount my scope so that the rifle is sighted in @ 100 or 200 or whatever and also ensure that my scope are at the bottom of the clicks. OH, and what do you guys think of the 1 piece Tally rings/bases??

 

[Mystic Precision]

longrangehunting.com and look at the articles on the left side. I have an article there to help you set up your scope for LR shooting.

The Burris rings is all you will need to get out to 500yds.

Jerry