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bore sighting with 20 moa rail

16617 Views 15 Replies 4 Participants Last post by  badshot
should i have to run my vertical adjustment almost all the way down to get close to bore sighted? Sorry for the dumb question but this is my first set up liek this. Thanks in advance.
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Guess I should tell you my set up. Rem Sendero rifle, Nightforce 5.5-22 x 56 NSX scope, Nightforce Rings and 20 MOA rail.
It depends on how much adjustments your scope has available. The 20 MOA taper means you will be dialing in at least 80 clicks of down (20 MOA) to boresite. If you only have 50 or so MOA, you will be down toward the bottom. (Sorry, don't know the MAX adjustments of the nightforce off the top of my head, but general rule of thumb is higher the mag, lower the amount of available adjustments)

MEL
Mel,

Thanks for the reply. I just checked the NF website ( http://www.nightforceoptics.com/nxs552256.html ) and it said elevation is 100 MOA (50 up, 50 down?).

Here is a cut and paste from that page:
MAGNIFICATION
5.5-22x

OBJECTIVE DIAMETER
56 mm

EXIT PUPIL DIAMETER
10.2 mm @ 5.5x
2.5 mm @ 22x

FIELD OF VIEW AT 100 YARDS
17.5 ft @ 5.5x
4.7 feet @ 22x

EYE RELIEF
95 mm / 3.740 in

INTERNAL ADJUSTMENT RANGE
Elevation 100 M.O.A.
Windage 60 M.O.A.

CLICK VALUE
.250 M.O.A.

TUBE DIAMETER
30 mm / 1.18 in

OCULAR LENS DIAMETER
36 mm

OVERALL LENGTH
15.2 in

WEIGHT
32 oz

MOUNTING LENGTH
6.6 in

AVAILABLE RETICLES
All NP Reticles
Mil-Dot, CH-1,2,3

Thanks for your help. SO this is normal and how it is supposed to be? Thanks again.
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Okay, 100 MOA is a good amount (the 30mm tube gives you more adjustment room).

If you are at the bottom (meaning you dialed in 50 MOA of down, or 200 clicks) then something doesn't seem right. If you are down anywhere from 15 - 30 MOA, I would not worry about it, in fact, the more down the better, as it gives you MORE UP adjustments for REALLY long shots.

MEL
Ok, I'm not all the way down to the bottom so that would mean I must be good to go? As a side note, They farthest I have ever shot successfully was just shy of 450 yards with a 7 rem mag and not this 300 ultra. That little javelina never knew what happened. I have only been out to 100 with the 300 since I am trying to find a hand load it likes. I do look forward to shooting out around the 1000 yard mark. I hope my scope will allow for that. Thanks again for your help and I will let you know after this weekend what I find when I go to the range.
With the .300 WSM you may not even need the 20 MOA taper to get out to 1000. With the taper, you shold be golden. Let us know how it shoots!

MEL
300 WSM? I'm shooting a 300 RUM. Where can I compare the ballistics of each to each other?
.300 WSM is about the same (slightly faster) than the .300 WM
.300 RUM is about 200 fps faster than that
I think the fps comparisons are a bit off, as I know you'll likely not shoot anything other than your own hand loads. That having been said, you'll load them to max capacity, and probably be 150-200 fps faster with identical bullets to the 300 WM.

I suspect you'll find a good accuracy load somewhere in the 80-90% of max pressure range (like everyone else) and still be 100-150 fps faster than a 300WM. :wink:
factory ammo wise:
Remington website .300 Rem Ultra Mag loads
180 gr- 3250 fps
.300 Win Mag:
180 gr- 2960 fps
290 fps improvement
Sorry about that, had it in my head that you were shooting WSM, the RUM is even better!! You shold have enough up clicks to get you WAY the heck out there

MEL
Looking at the Federal site regarding the Federal Gold Medal Match for the 300 WM, you find the 190 SMK being pushed at 2,900 fps. Not that they are the king of match-grade ammo, but it shoots pretty darn good for factory ammo. As far as I know, no one makes match ammo for the 300 RUM, except a few custom ammo builders, like D&L Sports. The speed of which is, at least to me, unknown, but certainly over 3,100 fps. Having said all this, I believe there is a significant difference between the accuracy load and the max hunting load for any rifle cartridge, expecially a magnum like the 300 RUM. I believe you will likely find the optimum accuracy load somewhere between 85-95% (+/- 2-3%) of max pressure (I checked my math and my earlier statement of 80-90% being too conservative), just like it is for virtually every other rifle caliber out there.

In any event if anything is unlucky enough to wander in front of you when you have hunting load locked and loaded, its time is likely up. :wink:
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Ok,

I did a little research and got some info on a load I am trying. This data is partially from the Nosler reloading guide (5th edition) to get a muzzle velocity from 88.0 grains H4831sc and 180 gr ballistic tip bullet shooting at 3205 fps. and part of it comes from a website I believe Jeffvn told me about to calculate the ballistics. Here it is.

Muzzle Velocity: 3205.0 ft/sec
Ballistic Coefficient: 0.507
Drag Function: G1
Bullet Weight: 180 grains
Sight Height: 1.50 inches
Wind Cross Speed: 0 mph
LOS Angle: 0 degrees
Target Speed: 0 mph
Zero Range: 100 yards
Temperature: 90.0 °F
Barometric Pressure: 29.92 in Hg
Relative Humidity: 85.0 %
Altitude: 300 feet
Air Density: 93 % of Sea Level


--------------------------------------------------------------------------------

Calculated Table
Elevation: 3.132 moa
Azimuth: 0.000 moa

Range Velocity Energy Momentum Drop Time
(yards) (ft/sec) (ft-lbs) (lbs-sec) (inches) (sec)
0 3205.0 4105.3 2.5 -1.5 0.000
50 3110.0 3865.6 2.49 -0.3 0.048
100 3016.9 3637.7 2.41 -0.0 0.097
150 2925.8 3421.1 2.34 -0.7 0.147
200 2836.4 3215.4 2.27 2.3 0.199
250 2748.8 3019.9 2.20 -5.1 0.253
300 2663.0 2834.3 2.13 -9.0 0.308
350 2578.9 2658.0 2.06 -14.1 0.366
400 2496.5 2490.8 2.00 -20.5 0.425
450 2415.7 2332.3 1.93 -28.4 0.486
500 2336.6 2182.0 1.87 -37.7 0.549
550 2258.8 2039.2 1.81 -48.6 0.614
600 2182.3 1903.3 1.74 -61.2 0.682
650 2107.1 1774.5 1.68 -75.6 0.752
700 2033.5 1652.7 1.63 -92.0 0.824
750 1961.5 1537.8 1.57 -110.5 0.899
800 1891.3 1429.6 1.51 -131.3 0.977
850 1822.8 1327.9 1.46 154.5 1.058
900 1756.2 1232.6 1.40 -180.3 1.142
950 1691.4 1143.4 1.35 -208.9 1.229
1000 1628.5 1060.0 1.30 -240.6 1.320
1050 1567.9 982.5 1.25 -275.5 1.414
1100 1509.6 910.8 1.21 -314.0 1.511
1150 1453.8 844.7 1.16 -356.3 1.612
1200 1400.8 784.2 1.12 -402.7 1.718
1250 1350.8 729.2 1.08 -453.6 1.827
1300 1303.8 679.4 1.04 -509.2 1.940
1350 1259.9 634.4 1.01 -569.9 2.057
1400 1219.0 593.9 0.97 -636.1 2.178
1450 1182.5 558.8 0.95 -708.2 2.303
1500 1149.7 528.2 0.92 -786.5 2.432
1550 1120.1 501.4 0.90 -871.4 2.565


Now for a short disclaimer. I will never shoot at an animal at distances over about 450 yards unless I spent alot of time at the range and learn exactly what my rifle does at ranges to about 600 yards. All of other distances will be shot at non-living targets only just to see if I can hit them. If I can shoot accurately enough I might try going further until I find my personal limits.

As a side note. at 1550 yards my bullet will drop 72.5 feet. Wow!
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thats about 50 MOA drop heh
5/6ths of a DEGREE!!!
woa...
CRAP!!!!!!!!!!!! i spent 30 minutes trying to format that so the table would be easier to read. I hate the internet. LOL
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