Long-Range Bullet Help


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Ol' KL
November 17, 2007, 02:36 AM
I want to try to do some long-range shooting (800yds).

For starters, I want to load some rounds for a .300HH. I want to use a hunting bullet, because if I can get good results on milk jugs, I may try it on a spring black bear. I have the following questions:

Am I better off with BC or Velocity...or compromise? I plan on using Nosler Accubonds, and I have kind of narrowed to the following weights/vel.:

150g 3200 fps/ BC .435
180g 3000 fps/ BC .507
200g 2800 fps/ BC .588

If I get into LR shooting, I'll probably buy a different gun. This one has sentimental value. I don't want really hot loads. Any idea where the extra velocity starts to take a toll on the barrel?

Thanks.

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Jim Watson
November 17, 2007, 07:48 AM
I don't know if there is a threshhold on velocity to cause throat erosion. Magnum loads cause magnum wear and tear.
You could plug your BCs and velocities into a ballistics program and see about what they will do. I recommend going for minimum wind deflection instead of flat trajectory. Anything that far out, you must know the range which then does not change. The wind does.
http://www.eskimo.com/~jbm/calculations/traj/traj.html

How do you plan to keep score? Spotting scopes will not resolve bullet holes at 800 yards. Hitting a water jug will be an exercise in frustration unless you are already zeroed or are on dusty ground so you can see your hits and walk them in.

USSR
November 17, 2007, 12:42 PM
Am I better off with BC or Velocity...or compromise?

Ol' KL,

Actually, you are better off with the bullet/load that shoots best in your rifle. Any of those weight bullets will bring a world of hurt to a black bear. And, since you won't be shooting bear at long range, bullet BC is irrelevent.

Don

rcmodel
November 17, 2007, 05:52 PM
I took it to mean if you can get close to hitting milk jugs at 8oo yards, then you want to shoot a bear at 800 yards. :eek:

If that is the case, you also need to be very concerned with bullet preformance at 800 yards.
Very few hunting bullets will have enough velocity to expand much, if at all at 800 yards.

So you may hit the bear, you may shoot a .30 cal hole through it, but may not kill it.

If you are going to reload, you need to buy a Speer or Hornady reloading manual. They contain detailed ballistics charts on every bullet they make. Then, you can see firsthand that the higher BC the better, as long as the cartridge you are using can push it fast enough.

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

Walkalong
November 17, 2007, 06:59 PM
want to shoot a bear at 800 yards. :eek:
Dang right. They are dangerous critters. :evil:

Good luck Ol' KL. 800 yard shooting is no walk in the park.

And welcome to THR, where we kid around as often as we are serious. :)

NuJudge
November 18, 2007, 02:19 PM
Using one of the Ballistic programs, try and find a bullet and load that will still have the bullet supersonic at the range you want to shoot, or the groups will go from mild to wild. I never shoot .30 caliber bullets further than 600 yards, but there are some bullets that I do not use even at that range because of the bad effect on groups of decending through the speed of sound.

Heavier bullets lose velocity much slower than lighter bullets, all other things being the same. A 190 or 200 grain bullet out of a .308 or .30-'06 should be going a good bit faster than a 150 or 168 grain bullet at 600 yards, despite having started out much slower.

You will see the same effect in the .300 H&H.

Calculators:
http://www.eskimo.com/~jbm/ballistics/traj/traj.html
http://www.mega.nu:8080/traj_dat.html

CDD

Zak Smith
November 19, 2007, 02:21 AM
Assuming the accuracy is the same, the bullet with the heavier BC is usually the better choice for long-range ballistics. There are some velocity/BC tradeoffs where a lighter bullet with a lower BC, shot "faster enough" vs. the heavier/higher-BC bullet, will have less wind drift at long range. Wind drift is the main clincher at long range, not flat trajectory ('cause once you get past the point-blank distance you need to dial or use reticle bullet drop compensation anyway-- which require an accurate range).

-z

Ol' KL
November 20, 2007, 03:08 AM
Thanks for the help.

I didn't notice it, but you're right the 200gr bullet overtakes (Vel.) the 180gr at 800yrds. Both should still easily be supersonic.

I'll start with the 200gr.

I appreciate the insight. I haven't done a lot of LR shooting. Last summer, I was getting pretty proficient at killing clay pigeons with a .223 at 400yrds, so I thought I'd switch to 8" balloons at 600yrds. I figured it would approximately the same...not! I did manage to score, but it was much more challenging.

It's pretty troublesome to dial in the scope on the .223, so I had to hold over. I plan to add some really good glass to the 300. I'll calculate my ranges with the 300 and dial them in. I think with the improvements, I should be able to work out to 800yrds.

Zak Smith
November 20, 2007, 03:14 AM
The most important thing to look at when comparing two loads/bullets long-range performance is the wind drift.

For example, here are whole bunch of different 308 loads

_Bullet_ _BC_ _MV_ 0 200 400 600 800 1000 | YARDS
175 SMK F 0.51* 2675 > 0.00 2.85 12.20 29.57 56.97 96.14 | wind (inches)
168 SMK 0.46* 2800 > 0.00 2.90 12.66 31.37 61.79 106.52 | wind (inches)
155 SMK 0.45* 2925 > 0.00 2.78 12.06 29.50 57.61 99.11 | wind (inches)
170 HPS 0.525 2740 > 0.00 2.59 11.05 26.62 50.88 85.42 | wind (inches)
155 Scenar F 0.508 2820 > 0.00 2.57 11.00 26.54 50.84 85.63 | wind (inches)
168 BER 0.512 2810 > 0.00 2.57 10.96 26.43 50.60 85.16 | wind (inches)
210 VLD 0.640 2400 > 0.00 2.54 10.72 25.55 48.18 79.61 | wind (inches)

175 SMK F 0.51* 2675 > 2675 2328 2009 1717 1457 1245 | velocity (fps)
168 SMK 0.46* 2800 > 2800 2412 2051 1709 1408 1176 | velocity (fps)
155 SMK 0.45* 2925 > 2925 2521 2149 1811 1497 1246 | velocity (fps)
170 HPS 0.525 2740 > 2740 2406 2099 1816 1560 1342 | velocity (fps)
155 Scenar F 0.508 2820 > 2820 2470 2147 1851 1583 1354 | velocity (fps)
168 BER 0.512 2810 > 2810 2463 2143 1850 1584 1357 | velocity (fps)
210 VLD 0.640 2400 > 2400 2146 1909 1688 1490 1319 | velocity (fps)

175 SMK F 0.51* 2675 > -2.00 -3.59 -31.06 -93.32 -203.26 -379.35 | drop (inches)
168 SMK 0.46* 2800 > -2.00 -3.14 -28.44 -87.30 -194.47 -372.54 | drop (inches)
155 SMK 0.45* 2925 > -2.00 -2.72 -25.54 -78.83 -175.24 -334.45 | drop (inches)
170 HPS 0.525 2740 > -2.00 -3.28 -28.75 -86.07 -185.98 -343.51 | drop (inches)
155 Scenar F 0.508 2820 > -2.00 -3.00 -26.98 -81.41 -176.85 -328.30 | drop (inches)
168 BER 0.512 2810 > -2.00 -3.03 -27.16 -81.84 -177.58 -329.26 | drop (inches)
210 VLD 0.640 2400 > -2.00 -4.75 -37.88 -109.42 -230.06 -413.67 | drop (inches)

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