bullet drop?educate me

[kramman]

i was hoping someone w/ a little more knowledge could help me out.im going to wyoming in 3 weeks so i bought a new scope for my browning abolt 270 and changed to shooting 130gr. remington core lokt bullets from the 150gr.Ive always shot the core lokt because that is the bullet my gun shoots the best.i switched to the 130 because we are hunting the eastern plains of wy.and it is supposed to be a flat shootinground.my ?i sighted in my scope to be 3inches high at 100.i stretched it out to 200and iam getting  absolutely no drop iam still 3 inches high ?can anyone explain this to me?the ballistics say i should be dead on at 200 if im 3 high at 100!also is the 130gr. to lite for mule deer out to 300? what kind of drop do you think i will be getting at 300yds.thanks kram

[Tony 270WSM]

http://www.biggameinfo.com/BalCalc.aspx

Just enter all the data you have and want it set for, and bingo!

[270Shooter]

Depends on the B.C of your bullet. But I would say at 3 inches high you should about dead on a 300 yards.

[demontang]

Here is what remington said the 130gr core-lokt out of a 270 will do.


Cartridge Information
Index Number Cartridge Type           Weight (grs.)     Bullet Style           Primer No.    Ballistic Coefficient
R270W2        Remington® Express®     130              PSP Core-Lokt®    9 1/2                  0.336

 
Velocity (ft/sec)
CartridgeType               Bullet               Muzzle   100    200    300     400    500
Remington® Express®   130 PSP CL       3060     2776   2510  2259   2022   1801

 
Energy (ft-lbs)
Cartridge Type           Bullet                 Muzzle    100     200      300      400       500
Remington® Express® 130 PSP CL         2702      2225    1818    1472    1180      936

 
Short-Range Trajectory
Cartridge Type            Bullet                  50       100    150     200     250     300
Remington® Express® 130 PSP CL           0.1      0.6     zero    -1.8    -5.1    -9.8

 
Long-Range Trajectory
Cartridge Type            Bullet                  100     150      200     250     300     400     500
Remington® Express® 130 PSP CL           1.5      1.4      zero     -2.8 -  7.0    -20.9   -43.3
 

[kramman]

yeah deamontang thats the same info i saw. it just doesnt explain why imnot getting any drop i cant figure it out even though im not complaining.
what about 1475ft lbs at 300 is this to lite for a big muley?i dont think so if it is put in the right spot.just wondering what some other opinions are.
thanks kram 

[300rum]

That's not too light, you will be fine.  the rule of thumb is around 900-1000ft lbs minimum.

[300UltraMagShooter]

Anyone know if there is a way to calculate a bdc reticle for a 300 rem ultra mag?  I just got a nikon scope for my rifle, but I don't know how to use it without just guessing/practicing.  Living in the city makes practice a little tuff...   

[JoshT]

At 100 yards the bullet is 3" high... and rising. The bullet reaches its apex at around 150 yards where it's 3.5" high... then it begins to decend... landing back at 3" high at the 200 yard mark. It will be dead on at 275... 1.5" low at 300 yards... and around 12" low at 400.

These are generic numbers for a 130 grainer at 3100fps... you should shoot the round at those ranges to verify the exact drop.

The generic chart looks like this:
100 = +3"
200 = +3"
300 = -1.5"
400 = -12.5"
500 = -30"

[DOUBLELUNG]

If you're 3" high at 100 AND 200 yards, your bullet is hitting higher than 3" above point of aim between 100 and 200 yards.  You're going to spend at least 30 hours round trip, $800+ on gas, a $312 tag, etc., etc.  Take a couple of hours to re-sight in with the new ammo out to 300 - or go back to the 150gr.  Right now, all you know is where you are at 100 and 200 yards; have a pretty fair chance of missing a 150 yard shot; and will be absolutely guessing beyond 200.  

That said, that bullet's fine for a 300yd shot on a big muley - but only if you know where your bullet is hitting at 300 yards.  There is NO EXCUSE for taking a 300 yard shot at an animal, if you haven't shot paper to at least 300 yards.  

If you're going to depend on calculated ballistics without even shooting the gun at that range, at least lower your 100yd point of impact to 1.5 instead of 3 inches high, and see if you're zeroed at 200 like the ballistic chart states.  You could then be somewhat confident of dropping no more than 7", if holding to a 300yd max. range.  If you're going that route, I hope you are using a rangefinder, otherwise all you'll be doing is spraying and praying beyond 200 yards.

[EastWaViking]

If you're 3" high at 100 AND 200 yards, your bullet is hitting higher than 3" above point of aim between 100 and 200 yards.  You're going to spend at least 30 hours round trip, $800+ on gas, a $312 tag, etc., etc.  Take a couple of hours to re-sight in with the new ammo out to 300 - or go back to the 150gr.  Right now, all you know is where you are at 100 and 200 yards; have a pretty fair chance of missing a 150 yard shot; and will be absolutely guessing beyond 200.  

That said, that bullet's fine for a 300yd shot on a big muley - but only if you know where your bullet is hitting at 300 yards.  There is NO EXCUSE for taking a 300 yard shot at an animal, if you haven't shot paper to at least 300 yards.  

If you're going to depend on calculated ballistics without even shooting the gun at that range, at least lower your 100yd point of impact to 1.5 instead of 3 inches high, and see if you're zeroed at 200 like the ballistic chart states.  You could then be somewhat confident of dropping no more than 7", if holding to a 300yd max. range.  If you're going that route, I hope you are using a rangefinder, otherwise all you'll be doing is spraying and praying beyond 200 yards.

   nicely said!

[norsepeak]

Josh,

I don't mean to be argumentative, but you stated that the bullet is 3" high and rising....actually the bullet never rises above the centerline of the barell,  What is happening is that based on your zero, your POA is lower than the arc of the bullet below the bore. 

The 270 will be just fine for mulies at those ranges, I use a 25-06 with 120 gr. on them and takes them down just fine. 

[demontang]

Ok, I looked a little harder at my ballistics tables and you should be sighted in for about 265-275yd. I would go back to the range and make sure that this is right before going out and shooting at an animal.

range (yards)                 Muzzle    50         100     200      300     400      500
Velocity (fps)                 3060      2916   2777    2510    2259    2023    1802
Energy (ft.-lb.)               2703     2454   2225     1819    1473    1181    937
Trajectory (265 yd. zero) -1.5        1.2     3.0       2.9     -2.6    -15.1   -36.0
Come Up in MOA              -1.5     -2.6    -3.1      -1.6      0.6      3.4       6.6

[JoshT]

Josh,

I don't mean to be argumentative, but you stated that the bullet is 3" high and rising....actually the bullet never rises above the centerline of the barell,  What is happening is that based on your zero, your POA is lower than the arc of the bullet below the bore. 
 

In one facet you're correct... the bullet does not "rise" above the centerline of the bore. BUT, the centerline of the bore is aimed UP into the line of sight. The line of sight (where the crosshairs are) is always flat... so the bullet is fired up into the line of sight... then it drops back down... so, there are actually two points on the bullets flight where it crosses the line of sight (or two ranges where it is 'zeroed'). In this case it is zeroed at about 40 yards (on the way up [or "rising"] into the line of sight)... and 275 yards (where it falls back down into the line of sight).

Here's a diagram to show what I'm talking about... I'm sure we're on the same page... just a matter of semantics.

[Intruder]

3" high at a 100 is too high IMO.  Sight the bloody thing 2.5" high at 100 yards and you'll have a +/- 3" point blank range out to almost 300 yards.

270 w/ a 130 grn is fine for mule deer.  You put it in the vitals behind the front shoulder and it's going down.     

[Colville]

I know you are shooting Rem. But Federal as a table where you can change your zero and other stats affecting the Bal's.

http://www.federalpremium.com/resources/ballistics_application.aspx

The 2006 version of that software says 130 gn nosler for 300 zero is: 3.6 high 100, 4.4 high 200, 0 300.

That jibes closely to your 3/3 numbers considering patterns aren't usually better than 1 inch for making estimates. You'd be on as others have said out beyond 250 and less than 300 for a zero.

As long as you are restricting yourself to that range the physics simply can't let you down too bad. 3 high at 200 leaves a pretty narrow window of outcomes at 300 unless you've found a box of factory ammo doing substantially more or less FPS than it's supposed to. It's just math.

The problem is we don't shoot one hole patterns so if you have 1 moa at 100 your outcomes at 300 should be someplace between +1 and -6 depending on the MOA you hold at 100. I miss by an inch on the low side, a +2 at 100 in the field you'll be -6 at 300. be inaccurate an inch high and you could be +1 at 300. Of course if you are off a full inch from POA  you are really shooting loser than moa, but you get the idea.

I'm not in disagreement with the prior about shooting our outfit at the range you intend to use itl. It's solid advice. But if you "know" where you put it at 200 there's only so many possible outcomes at 300.