Rifle Scopes Getting 77gr SMK to 500 yards w/ one revolution?

[Jason280]

I'm loading 77gr SMKs in my 20" AR, with a velocity around 2750fps at the muzzle. My goal is to use an optic that will get me to 500 yards within one revolution of the elevation turret, and I am looking at a couple of different scopes.

The scopes I am considering are a Burris Fullfield II Tactical 2-7x35, which has 1/2" clicks and the Ballistic Plex reticle, and a Nikon Monarch 4-16x42SF with mil dot and 1/4" clicks. Now, if I am reading the ballistic calculator correctly (using 2750fps, BC of .350, 100yd zero, and 2.5" scope height using a LaRue SPR 1.5), I will be 60.2" low at 500 yards requiring 23 clicks up with the Burris and 46 with the Nikon.

The Burris shows 24 MOA for one revolution, whereas the Nikon shows 12 MOA per revolution. Correct me if I am wrong, but it seems like one full rotation on the Nikon will get me to 500, while 1/2 turn should do with the Burris. Am I reading this correctly? If so, theoretically I should be able to get to just over 700 yards in one revolution with the Burris. Am I missing anything here?

 

[81sfo]

Re: Getting 77gr SMK to 500 yards w/ one revolution?

I shoot a RRA 20" barrel 1-8 twst Ar15,77 smks 24.1 varget/rld15.On top i have a Mk4 10x m1 Leupold scope zeroed at 100yds.The turrets have 15 moa per turn,to get to 600 i turn one full revolution plus 2 more moa.I dont have a chrony to get the muzzle velocity but i figure its close to 2700 fps.hope this helps.Ive never used Burris,my experience with a Nikon buckmaster 4-18x40 was not a good one.

 

[MontanaMarine]

Re: Getting 77gr SMK to 500 yards w/ one revolution?

I'm running Nosler 77s at 2650 fps (16" bbl). 12 moa gets me to 500 yards.

 

[dangerdan87]

Re: Getting 77gr SMK to 500 yards w/ one revolution?

With my Leupold MR/T 2.5-8x36mm, I can get out to 900 with one full turn held on center crosshair. Shooting about 2950fps.

 

[Jason280]

Re: Getting 77gr SMK to 500 yards w/ one revolution?

Dan,

Is your's the 1/2 or 1 MOA knobs?

 

[dangerdan87]

Re: Getting 77gr SMK to 500 yards w/ one revolution?

The scope is .5 MOA windage and eleavation. Though my turret knobs say "5.56 77gr SPR 1 MIN".

I think Leupold screwed up on the engraving when I exchanged the .308 knobs for 5.56 knobs.