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Old January 25, 2007, 12:18 AM   #1
mathman
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.308 168 grain vs 175 grain Black Hills for 100-600 yards

I know that the 175 grain is better for the longer range stuff...like 800 yards. Is there any advantage at all to the 168 grain bullet at shorter ranges like 100-600 yards? Or should I just shoot 175 grain for everything?

The gun that I'll be using is a Remington 700P LTR with Badger Mounts and Rings and a Leupold Mark 4 4.5-14x50 long range M1 scope.

The 175 grain bullets cost a little more than the 168 grainers, but not enough to sway my decision. Pretty soon I'll probably start to reload anyway.

Thanks for reading...
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Old January 25, 2007, 12:40 AM   #2
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It is a good idea to shoot one load, to preserve your zero and for data confirmation.
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Old January 25, 2007, 01:25 AM   #3
mathman
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Well, I already have 168 grainers...I guess I'll try them out and if they shoot well, I'll just stick with them...otherwise I'll try the 175 grainers. I probably won't shoot much (at least not seriously) over 500-600 yards.
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Old January 25, 2007, 03:43 AM   #4
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Will the 1-12 twist of the LTR be enough for the 175 grain bullets?
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Old January 25, 2007, 08:37 AM   #5
Tim R
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The 168's will serve you fine. Out at 600 and beyond, the 175's might buck the wind a little better and not require as much dope change depending on conditions.

In years gone by in another life, I've shot 168's out to a 1000 with open sights and a match tuned M-14. The 168's went sub sonic shortly before hitting the target and would often time key hole.

If you can find some 155 SMK match ammo, the 155's fly better than both the 168 and 175. The palma shooters shoot these out to a 1000 regularly.
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Old January 25, 2007, 11:28 AM   #6
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Find the bullet that shoots the best in your rifle and stay with it...
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Old January 25, 2007, 11:58 AM   #7
Hard Ball
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I favor the 168 graun bullets, It gives excellent all round performance.
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Old January 25, 2007, 01:45 PM   #8
joshua
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Most factory barrels have a 1-12 twist, which is not enough to stabilize the 175 grain hpbt match bullets out to 1000 yards. I've read and heard the common problem of keyholing. Get a 1-10 twist rifling if you can find it. josh
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Old January 25, 2007, 02:09 PM   #9
30Cal
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I've got a 1:12". It's a simple matter to find an accurate 168gr load. It took a little bit of work to get the 175 to group as well as it should. The 1:10" is a little iffy with 155's and less.
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Old January 25, 2007, 02:51 PM   #10
Zak Smith
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My 24" 1:12 has worked fine with the following bullets:

125gr Nosler BT
147gr FMJ ball
155gr SMK and Lapua Scenar
168gr Berger
175gr SMK
210gr Berger
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Old January 26, 2007, 03:21 AM   #11
mathman
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Thanks for the input...it's all a moot point at the moment since the dealer says that the distributor does not have any LTRs in stock. What a bummer...no telling how long it will be until they get some in stock. I'll be ready once it comes in.
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Old January 27, 2007, 10:54 AM   #12
Jimro
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175 grainers will buck wind better than 168 grainers at all distances.

That being said the 168 grainers are not bad at all for 600 and under. Try a box of both and shoot what your rifle likes best.

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Old January 28, 2007, 02:36 PM   #13
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Diminishing results

Quote:
I've got a 1:12". It's a simple matter to find an accurate 168gr load. It took a little bit of work to get the 175 to group as well as it should. The 1:10" is a little iffy with 155's and less.
I'm NEW to this arena and want to understand. At what point is it too much twist? Given you can spin the projectile enough that it would rip itself apart; if it spun at over 300,000 rpm (not sure what the twist rate was on that) which according to ballistics tables they do, then at what point do you say it's good enough?

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Old January 28, 2007, 03:02 PM   #14
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Twist rate is directly related to velocity. The velocity and twist rate determines the RPM of the projectile.

For example a 30 caliber 1:10 twist will stabilize a 190 grain projectile at normal velocities, anywhere from 308 to 300 win mag velocities.

When you start getting subsonic, you need to tighten up the twist rate so that the bullet stabilizes properly. Using a 300 Whisper you need a tight twist to stabilize those heavy pills going slow.

Conversely a 1:12 twist normally shoots 175 grain SMK's just fine even tho many people say that it won't. Heck, I've shot 168 grain SMK's subMOA out of my 1:14 twist barrel out to 200 yards (don't have a range longer than that to test it at real distance).

The Greenhill formula is still a useful tool for ballparking things, but don't let it have the final word.

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Old January 29, 2007, 05:31 PM   #15
ranger dave
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7 g

the 175g load came from the us army and the m 21 sniper rifle with its funny 5 land barrel the 168g otm is the best bullet for the 1 in 10 twist 308
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Old January 29, 2007, 06:47 PM   #16
Jim Watson
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Try both.
At the Sierra maximum velocities of 175 gr @ 2600 fps and 168 gr @ 2700 fps, the 175 will move an inch more in a 5 mph breeze at 600 yards. An inch on the target, not a MOA. That ain't much.
So shoot some of both and use the one that is more accurate in your rifle.
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Old January 29, 2007, 06:56 PM   #17
30Cal
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Quote:
At the Sierra maximum velocities of 175 gr @ 2600 fps and 168 gr @ 2700 fps, the 175 will move an inch more in a 5 mph breeze at 600 yards.
The 175 drifts LESS.
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