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Old March 31, 2006, 07:58 PM   #1
Hello123
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1:10 inch twist 308 most accurate bullet?

What do you all think would be the most accurate bullet weight and type for this twist in 308?
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Old March 31, 2006, 09:25 PM   #2
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168gr Sierra Match King HPBT Moly Coated...
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Old March 31, 2006, 09:31 PM   #3
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I would start with 150 or 165 grain bullets and try a couple of diffrent brands even . My local gun shop will set up a variety pack with 6 of each bullet for a nominal price depending on the caliber as to the price for 30 cal I think it is around $25 but you get 115 rounds and it is a lot of fun to play with. I have also seen these variety pacs on E- Bay
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Old March 31, 2006, 10:07 PM   #4
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Think the 168gr, HPBT MAtch bullet (hold the molly) is proably going to be the most likely for the accuracy title reguradless of the barrel twist rate. That 1:10 might be worth trying heavier weight bullets...slower start speed, but they tend to hold on to what they start with better, so the down range ballistics are very good even with the slower start.
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Old March 31, 2006, 10:50 PM   #5
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168 MatchKing here too, hold the moly. Don't overlook the Hornady Match bullets and the A-Max line, they are making some really fine bullets too.
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Old April 1, 2006, 01:31 AM   #6
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You might check out Berger (expensive) -

http://www.bergerbullets.com/catalog.htm

I'm using 175gr moly SMK's in a 1/12 twist.
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Old April 1, 2006, 03:49 AM   #7
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The only guy I know with a 1:10 twist barrel prefers the 175 grain.
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Old April 1, 2006, 06:18 AM   #8
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I agree with the 165-168 match BTHP's

It seems that the optimum weight is at about 165...

The heavier bullets will hold course better at longer ranges so you may want to try the 175's as was offered by 270

The 150 is too light for most .30 caliber barrels, especially at 300 yards and up.
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Old April 1, 2006, 11:48 PM   #9
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I would say 168 Sierra Match King HPBT. But try others as they may work for your gun. I just started loading for .308 and bought 168gr SMK, Hornady 168gr Match, and Hornady 165 BTSP. The sierra had the best group of .45" at 100yds. The hornady match was at .50". I believe better results could be gotten with a rear bag.

So start with the 168gr SMK. It is a proven bullet for the .308.
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Old April 2, 2006, 09:47 PM   #10
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At what range?
The 168 gr Sierra was originally known as the "International" because it was meant for 300 metre ISU shooting. It is ok to maybe 600 yards but some places don't even allow it on the range at 1000 because it drops subsonic and loses stability at .308 velocities.
I shoot the 175 SMK for F-class Long Range.
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Old April 2, 2006, 10:52 PM   #11
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Jim has it right. The 168 SMK was designed in the late 50's. It was designed for 300 meters, and they got lucky in that it performs well out to 600 yards. But when I went through Gunsite's PR1 class in 2000, 168 grain SMK's were in the PMC match we bought out there (to skip having to load and ship ammo). The one 741 yard popper shot we had across a valley couldn't be hit by anybody more than very occasionally. The 168's were not simply going sub-sonic, they were tumbling. This was confirmed a couple years later when I first attended the Long Range Firing School at Camp Perry. The firing starts at the 800 yard line. A lot of people brought 168's and couldn't stay on the paper. Those that did got reports of keyholing from the pits, so these bullets were sideways when they hit.

The 175 was designed in cooperation with the military to create a 1000 yard .308 bullet. It is a newer tangent ogive design. My first group with it at 800 yards was a 99-4X. It works great. The weight difference isn't enough to appreciably cut your powder supply. If that worries you, go to Winchester cases which have a so-called "solid balloon head" to create a couple of grains of extra capacity. Be aware these cases are nowhere near as consistent in manufacture as Lapua or Norma, so if you want high precision you will have to get a gauge setup and sort them for uniform wall thickness.

The 1 in 10 twist was in use by the military when they chose 172 grain boattails as best for match ammunition, first in 30-06, then in .308. Most of the M72 and old M118 bullets I have pulled have actually weighed in at about 174 grains. Samples from the two lots of 175 grain SMK I have also weigh in at 174 grains. The 168 grain SMK originally displaced the military 172 grain bullets in matches at 600 yards and shorter because their solid bases and superior jacket manufacturing consistency more than made up for any slight weight or shape drawback. With the 175 grain SMK now available, no compromise need be accepted.

Nick
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Old April 2, 2006, 11:27 PM   #12
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Jim Watson

Ever try Begers for F-Class?
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Old April 4, 2006, 10:40 AM   #13
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1 in 10

Hello123,

Jim Watson and Unclenick hit it right on the head. The 1:10 twist is better suited to a 175 grn bullet (or heavier). The 168 grn prefers a 1:12.

The 1:10 causes to much rotation on the lighter bullet. The 175 SMK or 190 SMK need this twist to stabalize.

Bullet94, the Berger VLD's work real well, but introduce a whole new set of problems with Mag lengths VS bullet jump (distance to lands).

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Old April 4, 2006, 05:27 PM   #14
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Bullet '94,

I've heard several people, including a fellow with the lab gear to measure it, that the Berger's are actually more consistent than the Sierra's. I will start using some 80 grain Berger VLD's this year, but only for single-loading at the 600 yard line. No way to get it in a magazine.

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Old April 5, 2006, 07:32 AM   #15
Jim Watson
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Bullet94

I have shot some Berger flatbase bullets in other rifles and did not find them more accurate than SMKs. I do have some JLK VLD 90 gr .224s on order for that fast twist .223, though.

I think too much is made of the difference between 10 and 12 twists and you will really have to let the rifle tell you which is more accurate over a pretty wide range of bullet weights.
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Old April 6, 2006, 09:32 AM   #16
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Twist rates

Bullet94,

Jim is right about twist rates, I have heard of people selling rifles "because they heard" the rate wasn't right. It will cause, (with the same speed) a 168 or 175 to behave differently, a miniscule difference that shows up at long distance.

The way to overcome the twist difference is simple, if you have a 1:10 twist and use the 168SMK, simply load the round to a lower node, if you have a 1:12 and use a 175SMK, load to a higher node, to obtain optimal accuracy.

Try a couple boxes of Federal Gold Medal Match 168 and 175's or Black Hills 168 and 175's and see what she likes the best, then load your own.

For what it's worth,
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Old December 19, 2013, 01:27 AM   #17
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Huh?

First off a 1:10" would be 175 and 1:12" would be 168. not vise versa!!?
Anyways I love how all these people say the 168 is the only way to go and zoo many agree. The. The real shooters comes on with some actual facts and say the 175 is best. "Which it is"
Most 1:10" rifles wile group better with 175 some like 168 but only at
Short ranges. Your MOA will skyrocket compared to the 175 which is solid.

I think a much better question is what is better forong range a 175smk or a 190 or even to the extreme Berger hybrid 230grn.( a great round with amazing bc but really only works in the magnums. But the 190's I am curious?

By the way if you don't reload an even more accurate ammo than federal gold medal is southwest ammo. These marines can reload some accurate stuff. I mean I can hardly outdo the. With Lapua brass and neck turning. It is amazing accurate!!! They will even take your brass formed to your bolt
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Old December 19, 2013, 09:25 AM   #18
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It's been my experience and observation of a lot of top ranked competitive shooters wearing out several .308 Win barrels in the 1960's to 1990's obtained when it was "the" cartridge to use for competition in NRA and military match rifles:

1:8 twist 28" barresl shot 240's and 250's out slow, but accuracy at 1000 yards was as good as anything else.

1:9 twists have shot 220's very accurate.

1:10 twist is best for 200 and 210 grain bullets. +P loads in M14NM's with 1:10 barrels using 180's shot good enough to set some records.

1:11 twists were the winning numbers for 168's through 200's being shot in the same 26 inch barrel. But the 168's were used in reduced loads for short range use. With 22 inch M14 barrels having 1:11 twists, max loads with 168's through 175's won a lot of matches and set many a record.

1:12 twists were perfect for 165's through 180's, but also worked very nice for +P loads using 190's in Garands. And the 7.62 NATO design criteria for 150's used in M14 service rifles was a 1:12 twist as it gave the best accuracy with the standard M80 round's bullet and also shot 172-gr. match bullets more accurate than the same bullet from a .30-06's 1:10 twist (based on extreme spread, not mean radius).

1:13 twists were still are the norm for 30 inch barrels shooting 147's and 155's in long range competition. Some folks have even used 1:14 twists with excellent results. Sub MOA at 1000 is the norm with such stuff.

Such twists put the stability factor for .308 Win. bullets close to the small end of an acceptable range which is best for pristine accuracy using the JBM calculations. Benchresters spin their bullets just barely fast enough to get the same, best accuracy results, for the same reasons.
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Last edited by Bart B.; December 19, 2013 at 09:56 AM.
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Old December 24, 2013, 03:08 PM   #19
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Given the diversity of opinions here we have successfully confused Helo123. So offering what I know will only add to the confusion.

Here's the answer: Call Sierra or one of the other bullet makers and ask them. They will give you the straight beef.
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Old December 24, 2013, 03:53 PM   #20
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Eppie, Sierra and all the rest will give the same range of answers. That's been happening since the early 1950's when the .308 Win first came out with 1:12 twist barrels in the Winchesters then went wild when Remington used 1:10 twist barrels in some of their .308's.

Such is life when the question asked doesn't have a long list of specific rifle conditions and accuracy standards stated for the most accurate bullet weight and type for a 1:10 twist in a .308 Win barrel. This isn't meant to say Hello123 didn't provide enough details; his question was just fine in my opinion. We just gave our opinions and examples to help him decide.

There is no "exact" answer.
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Old December 24, 2013, 05:26 PM   #21
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Thanks Bart B that was some of the best info on the 308 and there twist and bullet weight. I am a old Navy man.
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Old December 25, 2013, 06:45 AM   #22
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I don't normally engage in thread necromancy, I'll point out that barrel length has a role to play here.

a 16.25" barrel won't give you the same velocity as a 26" barrel, so having a tighter twist is not a bad thing here to ensure good stabilization.

I'd also like to point out that flat based bullets are generally more accurate at short ranges than boat tail based bullets. So I would expect to see a 180gr flat based bullet shoot very well at 100 yards from any 1:10 twist barrel of reasonable length.

You can't tell by twist rate what bullet a barrel will shoot best, but the answers given are all good places to start.

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Old December 25, 2013, 10:25 AM   #23
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My model 11G likes the 168gr Lapua Scenear bullets.
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Old December 25, 2013, 12:45 PM   #24
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A couple of months ago when I was ordering my custom rifle, I did a bit of research. The general parameters are that standard calibers have a "standard" twist rate. However, when someone wants to shoot a given caliber further, they will normally resort to heavier/longer bullets, and to stabilize them, a faster twist rate is required. However, as one increases the twist rate the coriolis effect influences the bullet trajectory.

Hello123 1:10 twist is only a bit faster than the standard 1:11 for .308. I don't know what is the heaviest bullet you can shoot with that rifle. But it would be fun to find out if recoil is not an issue for you.
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Old December 27, 2013, 10:25 AM   #25
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Eppie, how much does a bullet's coriolis effect influence its trajectory if the twist goes from 1:12 to 1:11, or 1:11 to 1:10 for a given 30 caliber bullet leaving at a given muzzle velocity? MOA units at any range are fine to describe the change.

I ask because I've shot .308 Win's with 190's at 1000 yards from 1:12, 1:11 and 1:10 twist barrels with no difference in accuracy.
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