Can somebody help me with the ballistics of two different .308 bullets?


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avs11054
February 1, 2013, 06:03 PM
I am looking at .308 bullets on Federal's ammo and ballistics catalog. Specifically, I am looking at the 150 gr nosler partition and the 180 gr nosler partition. I am trying to determine what bullet to use for elk this coming year.

My question is, why should I choose one over the other, and what do each of them do that the other does not do? The catalog says that the 150 gr is for medium game and the 180 gr is for heavy game, but I honestly do not see that big of a difference between the two. Maybe I just do not know what a big difference is.

Velocity:

150 gr
50 - 2721
100 - 2604
150 - 2491
200 - 2380
250 - 2273
300 - 2168
350 - 2065
400 - 1966
450 - 1870
500 - 1776

180 gr
50 - 2478
100 - 2388
150 - 2299
200 - 2213
250 - 2128
300 - 2045
350 - 1965
400 - 1886
450 - 1809
500 - 1734

Energy

150 gr
50 - 2687
100 - 2466
150 - 2067
200 - 1888
250 - 1721
300 - 1565
350 - 1421
400 - 1288
450 - 1164
500 - 1051

180 gr
50 - 2455
100 - 2279
150 - 2114
200 - 1958
250 - 1811
300 - 1673
350 - 1543
400 - 1421
450 - 1308
500 - 1202

Also, what does a "nosler partition" mean. How is that different from a nosler ballistic tip?

Thanks for the help

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jmr40
February 1, 2013, 07:13 PM
The Partitions are designed to hold together and drive deep into larger animals like elk. The Ballistic tip is basically a hollowpoint with a plastic tip. They are designed to expand rapidly, but not penetrate deep. Not the best choice on elk. Of those 2 I'd forget the Ballistic tip and go with the Partition.

Go to www.nosler.com and look up the bullets BC. Plug in the numbers here.http://www.hornady.com/ballistics-resource/ballistics-calculator. And you can figure out the ballistics.

FWIW, I'd suggest either a 150 gr Barnes TTSX, or 165 gr Nosler Accubond. They both fly flat because of their aerodynamics, and hold together for good penetration. Basically you are getting the flat trajectory of the Ballistic tip, with a tougher bullet like the Partition.

Using 165 gr Accubonds @ 2740 fps at the muzzle I can still get 2029 fps and 1535 ft lbs at 400 yards with about 31" of drop with a 100 yard zero.

avs11054
February 1, 2013, 07:36 PM
Thanks for the response and the suggestion. I guess another question I have is that I have read a lot of people who talk about needing a heavier bullet for elk. Of these two, why would I choose the 180 over the 150 when both travel roughly the same speed with the same energy.

MutinousDoug
February 1, 2013, 08:09 PM
Heavy bullets expend their energy differently than light ones, are more likely to break into larger pieces than lighter ones thus are likely to penetrate deeply after hitting large bone.
So, two bullets of the same construction given the same energy, the lighter bullet is more likely to fragment, limiting penetration. This might be desirable on light game but less so on larger game where your bullet may encounter heavy bone before entering the vitals.
I wouldn't hesitate to shoot 150gr bullets at elk if that's what I had. Every shot taken will yield different results but you want to take out both lungs on an elk and get an exit wound to track. So much easier that way.

avs11054
February 1, 2013, 08:22 PM
Awesome. Thanks for the answers. Those were exactly what I was looking for.

jmr40
February 1, 2013, 10:36 PM
Heavy bullets made of the same construction methods will penetrate deeper. With old 1800's technolgy going to a heavier bullet, was the only way to get deep penetration on large animals But not all bullets are designed the same. With newer bullets made in the last 15-20 years it is now possible to get lighter, flatter shooting bullets to outpenetrate old school bullets that are much heavier.

The Ballistic Tips are designed to almost explode on impact and give very little penetration. They kill quick, if they get to the vitals, such as on a deer. But on a larger animal such as elk may break up before getting deep enough. A 180 gr Ballistic tip will penetrate deeper and do more damage than a 150 gr Ballistic tip. While they both my work on elk, they are not the best choice. A bullet has to hold together and penetrate deeper on a 700 lb elk in order to get to the vital organs than on a 150 lb deer.

The Ballistic tips are made with a high BC to make them more aerodynamic. They shoot very flat at long range.

The Partitions have a lower BC, so they lose more speed at longer ranges, but they are a tougher bullet that will not break up on impact. A great choice on elk even in lighter bullet weights.

The Accubonds have a very high BC and maintain speed well at long range. They are also just as tough as the Partitions for deep penetration. Same with the Barnes bullets. A 150 gr Accubond, or Barnes TTSX will out penetrate and do more damage than even the 180 gr BallisticTip because they are a tougher bullet.

avs11054
February 1, 2013, 10:44 PM
So how would a nosler partition perform on a deer? Is there more of a chance that it would go through the deer without any expansion than a ballistic tip?

natman
February 2, 2013, 08:11 AM
The Partition is really two bullets in one. The tip expands normally for a big game bullet. However expansion is limited by the partition, so it can only expand so far. It's an excellent bullet for really big game.

The Ballistic Tip is all one piece and gives more rapid expansion than a Partition. Fine for varmints and maybe deer, but not what you want for elk.

For elk the 180 Partition is the way to go. Because it is the same diameter as the 150, but has more weight, it has better sectional density, a measure of how far it will penetrate all else being equal.

MCgunner
February 2, 2013, 07:26 PM
The partition has a copper partition through the bullet that stops expansion before the core of the bullet is lost, insures penetration. The Ballistic Tip is like a hollow point with a plastic point installed, great for thin skinned game, though animals not so much. I find both to be accurate, but the BT is a boat tail, higher ballistic coefficient allow for better down range numbers and less drop.

Partition (a pistol bullet)

http://www.missouriwhitetails.com/forums/files.php?pid=1349971&aid=66271

BT It's a lead free. I couldn't find a cut away of a lead boat tail BT. I really like the 150 BT in .208" on deer, fantastic and plenty of penetration. In fact, I use it on hogs, now. I load a Barnes 140 for hogs that is great, but I've found the BT works plenty well on 'em and has more than enough penetration.

http://upload.wikimedia.org/wikipedia/commons/7/71/Nosler_Ballistic_Tip_Lead_Free_Cutaway.jpg

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