I'm going on an Alaskan Mt. Goat hunt in Prince William Sound next week.

I've sighted my .300 Jarrett shooting 200 gr. Nosler Partitions @ 3050 fps 3" high at 100 yards. At 200 yard it is about 3 1/2" high, 300 yards it's 2" low and at 400 yards it's 12" low. This is at sea level and 75 degrees.

My questions is, how will these numbers change when shooting at a Mtn. Goat 5,000 ft above sea level at 35 degrees?

Will the change be significant enough to compensate for, or should I just go with the sea level, warm weather bullet drop data?

Go here it will figure all that stuff up for you
http://www.robsoft.nu/ballistik_en/default.asp?MainID=3

If you stay under 400yds you're fine. Wind is going to be a bigger factor in the mountains.

Somehow I don't think just 5,000 feet and 35 degrees will effect it enough to worry about. Alittle less air resistance but slightly less velocity too. Ten thousand feet certainly would or zero degrees would.

Thanks for the replies!

The link provided by rws2 was very helpful. I plugged in the numbers and ran the calculations at both temperatures and altitudes and the results show a minimal change in trajectory, less than 1/2" out to 400 yards.

So, as fred pointed out, I will concern myself more with the wind than with the trajectory.

I think that your main concern will be shooting angle. Remember, if you shoot up or down at a steep angle, it will have a very noticeable effect on the trajectory. Your bullet will strike high when shooting down(or up) at a steep angle. In other words, say you're shooting at an animal at a ranged 400 yds. Given the trajectory you've shown, you would hold up 12", maybe on the back. Well because of the steep angle, you would shoot over it. This has happened to me before and is verifiable with ballistic tables.You would most likely want to hold on the normal kill zone.

bowhuntr

Mark,
Just for comparison.
I shoot my 300 win mag using the same 200 gr nos partition at 3100fps.
3 1/2" high at 100
0 at 300
-10 at 400

My elevation is 2500 feet and the temperature was in the 70's when I measured these drops on targets.
As you already discovered from the tables sounds like there is not much difference due to the elevation.
As others have stated the bigger issues are the wind and the shot angles.
Good luck on your hunt!

Mark,
goodluck on your hunt.
Remember, the further the crittur the harder you gotta pull the trigger
Is your lovely lady going with on this trip?

If you go to http://www.handloads.com/calc/ , the ballistics calculator allows you to change temp. and altitude as part of the group of changeable variables used to calculate the trajectory figures.

You need to enter these, as well as MV, B.C., and zero range....

A lot of fun trying different "what if" questions. Good luck in Prince William Sound! A great place to hunt, view beautiful terrain, and take a lot of great pictures!!

Looks like you'd have about 0.5" less drop at 5000 ft. and 35 degrees F than you're now getting, out to well beyond 300 yards..... Half an inch is less than your holding error at such distances.

Your current ballistics @ 75 degrees, 0' altitutde, wind 90 deg. @ 10 MPH:

Range Vel POI Drop ToF En. Drift
0 3050 -1.5 0 0 4131 0
25 2995 0.01 0.17 0.03 3984 0.47
50 2945 1.28 0.58 0.05 3852 0.58
75 2896 2.31 1.24 0.08 3725 0.77
100 2848 3.06 2.17 0.1 3602 1.03
125 2800 3.55 3.36 0.13 3482 1.36
150 2753 3.76 4.83 0.16 3366 1.77
175 2706 3.7 6.58 0.19 3252 2.26
200 2660 3.32 8.64 0.21 3142 2.84
225 2614 2.64 11 0.24 3035 3.49
250 2569 1.63 13.69 0.27 2931 4.23
275 2524 0.31 16.7 0.3 2829 5.06
300 2480 -1.37 20.06 0.33 2731 5.98
325 2436 -3.4 23.77 0.36 2635 6.99
350 2393 -5.8 27.85 0.39 2543 8.09
375 2350 -8.56 32.3 0.42 2453 9.29

Proposed at 5000'altitude & temp of 35 degrees, wind 90 deg. @ 10 MPH:

Range Vel POI Drop ToF En. Drift
0 3050 -1.5 0 0 4131 0
25 3001 -0.01 0.17 0.03 4000 0.46
50 2956 1.24 0.58 0.05 3881 0.56
75 2912 2.24 1.24 0.08 3766 0.73
100 2869 2.98 2.16 0.1 3656 0.96
125 2826 3.46 3.34 0.13 3547 1.26
150 2784 3.67 4.79 0.16 3442 1.62
175 2741 3.59 6.53 0.18 3337 2.06
200 2700 3.23 8.56 0.21 3238 2.56
225 2658 2.57 10.88 0.24 3138 3.14
250 2618 1.59 13.52 0.27 3044 3.8
275 2577 0.3 16.47 0.3 2949 4.53
300 2537 -1.32 19.75 0.33 2858 5.33
325 2498 -3.28 23.37 0.36 2771 6.22
350 2458 -5.59 27.34 0.39 2683 7.18
375 2419 -8.26 31.67 0.42 2599 8.23
400 2381 -11.3 36.37 0.45 2518 9.36
425 2343 -14.73 41.46 0.48 2438 10.58
450 2305 -18.55 46.94 0.51 2360 11.89
475 2268 -22.79 52.84 0.55 2284 13.28
500 2231 -27.44 59.15 0.58 2211 14.77

[ 10-09-2003, 18:22: Message edited by: eldeguello ]

500Nitro, good to hear from you! Congratulations on your last hunt, looks like you Perry and Colin took some nice trophies.

Yes, Holly will be with me in Alaska. However, she has better sense than I and will spend 7 days aboard the luxury vessel watching whales, eagles and bears on the beach, fishing, kayaking and sipping wine in the hot tub on the upper deck. Check out the boat at www.alaskanadventuretours.com

Meanwhile, I will be climbing through the devil's club with a 60 pound pack to 5,000 feet so I can freeze my ass off in a tent, eat freeze dried food, and hopefully, kill a nice Mtn. Goat before falling off the mountain or having a heart attack.

It's no wonder women live longer than their husbands, they have better sense.

eldeguello, thanks for the exterior ballistics info. The wind drift figures will be very helpful.

Pop,
It is with the Federal High Energy factory loads.
26" barrel H-S Precision Rifle.
3118fps avg. of 3 shot string chronographed at 10' from the end of the barrel, appx. 75 degree day.

Box says it should be 2930fps with a 24" barrel.

I called the factory and talked to the tech guy and he said it was pretty unusual to be getting that kind of velocity as well.
Its a great load in my rifle with excellent accuracy and no pressure signs.

I was only getting a little over 3000fps with my handloads for this bullet.