Nikon m223 rapid action. 55vmax Loads?

[sconnie264]

I have an r15 (22") and 3x12x42 m223 scope. I whipped up some surprisingly accurate 55vmax loads pushed with Benchmark (.2" 3 shots 100yd) and my chrony's averaging 3250fps, but the elevation markings aren't very close to what it should be. At 400 my scope is set 350ish, etc. Is the velocity claim on the scope turret (55vmax @3240) correct? Am i outrunning most factory ammo in 55gn bullets? Considering that Nikon probably based their adjustments on box ammo. Any feedback is appreciated.

 

[rdsii64]

I have an r15 (22") and 3x12x42 m223 scope. I whipped up some surprisingly accurate 55vmax loads pushed with Benchmark (.2" 3 shots 100yd) and my chrony's averaging 3250fps, but the elevation markings aren't very close to what it should be. At 400 my scope is set 350ish, etc. Is the velocity claim on the scope turret (55vmax @3240) correct? Am i outrunning most factory ammo in 55gn bullets? Considering that Nikon probably based their adjustments on box ammo. Any feedback is appreciated.

Since that scope is a second focal plane scope you could adjust the magnification until the little circles correspond to the correct ranges.

 

[sconnie264]

Since that scope is a second focal plane scope you could adjust the magnification until the little circles correspond to the correct ranges.

It is a graduated turret, not a mil-dot type scope or that'd deffinatly work. Thank you for the response though!

 

[timmay]

probably a dumb question but did you make sure you have it zeroed for what the scope suggests? Some make you have something other than a 100 yd zero for the bdc reticle to work. Might have to have a 50/200 yd zero

 

[battlestick]

Is your altitiude the same as what the scope was built for? My guess says you are not very close to 8000 feet, and if you are pretty close to sea level, it is not very warm.

 

[sconnie264]

Is your altitiude the same as what the scope was built for? My guess says you are not very close to 8000 feet, and if you are pretty close to sea level, it is not very warm.

That makes alot of sense! Is that scope actually made for 8000ft?

 

[battlestick]

Most scopes with BDC reticles are made for an average. This would minimize the amount of discrepancy at varying altitudes.

For example, if you were at sea level and the reticle is calibrated for 16k feet, you will be way off....and vice versa. So to minimize this and to appeal to the broadest market, manufacturers have to compromise somewhere. This is why in the manual for each scope it still tells you that you must shoot it to verify.

One way to utlize a BDC reticle that doesn't match your loads is to tune your load to the reticle. Play with a ballistic calculator and find out what velocity at your altitude will get the closest to the calibration for your reticle. Then find the node your rifle likes closest to that velocity. Then of course, shoot to verify.

I can help with this and give you real world examples if you like. I have done this for two rifles with the Vortex BDC retcile.

 

[sconnie264]

That would be great! Always appreciate the help!