twist rate for .308?

[bigamehunter93]

Hey guys, starting a .308 build with a 26" tube and was wondering what you thought about twist rates. Looking for long range a max distance of 1200yds. Going to be pushing the 168gr. matchking primarily for hunting and something heavier for long range target. What twist will I need to make the 168 work? Also what bullet would you recommend for 1000+ yds?

[nicknitro71]

1000+ with a .308? Good luck! But if you are set on that caliber, go with 12 twist. As for bullets, Berger, Sierra are great but make sure you pick a boat-tail.

[30Cal]

The 168 matchking will fly fine with whatever twist. However, it is not a hunting bullet. The only design consideration was making it reach a piece of paper. Guy on AR15.com posted a photo a couple days back of what was left of the shoulder of a deer he shot with the Hornady flavor of the same bullet. Nothing really left to eat.

http://www.ar15.com/forums/t_10_23/6...8_bullet_.html

The 165 gr Gameking is a good bullet.

[4EVERM-14]

1/10,1/11, or 1/12 twist will work. The long range shooters lean towards 1/11 and sometimes 1/10. These offer a chance to stabilize heavy 175gr and 180gr bullets. I shoot a 1/10 with 168's in my M1A service rifle but limit to 600 yards.
Beyond 600 yards the 308 needs stiff loads to remain supersonic. The 175 SMK was designed for this purpose and is very popular. One shooter likes the 30-06 for 1000yards with a 1/11 twist but with the '06 he can launch 190's and 200gr. slugs.

[1Hobie]

http://www.thehighroad.org/archive/i...p/t-69384.html

Why not a .308? It's a challenge but quite doable.

[bigamehunter93]

Im wanting a .308 so that I can have a little cheaper reloading expenses for my long range addiction . I shoot long range high caliber with a .338 Lapua improved and a .375 snipetac. Ive never dealt with a .308 therefore I apologize for me looking like a bit of newbee. I really like the 175 SMK so I may run that first. 1:10 sounds like a winner to me.

[Slamfire]

When I barrel a 308 target rifle I buy a 1:10 twist barrel. I have no idea why the military chose a 1:12 for the 30-06 when they used a 1:10 from 1906 to the 1960's and never had an issue with 150's. The 1:10 will shoot 190's, I shot 200's in the 30-06, and they all shot very well at distance.

I thought 190 SMK's were the greatest bullet at 1000 yards, but an F class champ told me they were no longer considered a winning bullet. What they are shooting right now, FTR Class 308, is the Berger 185. What shooters will use next year, heck if I know.

I have also shot 175 SMK's at 1000 and can't complain.

I shot 168's and they keyholed at 1000. That was the last I did that.

[CharlieDeltaJuliet]

The .308 is capable of way farther than 1000yard shots. Like others have stated, the faster twist is usually the choice of most for shooting longer ranges with heavier weight projectiles.. I shoot a 1 in 10 twist, but mainly shoot 178 grain AMAX or 175 grain SMK's. But let me make this clear, I only punch paper with this ammo...I have seen a 308 hit steel at a mile.. The math is the most important issue. If you get a chance, watch the "Magpul Art of the Precision Rifle". Todd Hodnett teaches people to shoot a mile with the .308. It is worth the watch. A .308 at long range is like entering a Mazda Miata at a road race. While you can win, it takes a lot more skill.

I also use my .308 to offset my long range habits. I use my 50 BMG at anything over 800 yards though.

[4runnerman]

nicknitro71-- I have shot my 308 at 1000 yards for 3 years now. Not a problem at all,Very easy and very do able. I would not recommend the 168 though. Go with the 175 SMK. One in 9 twist will do it very good, One in 8 would be better,but i have no issues with a one in 9.



but an F class champ told me they were no longer considered a winning bullet. What they are shooting right now, F Class 308, is the Berger 185

Slamfire- Are we talking F-Class or FTR-Class?. I find it hard to believe any one would enter F-Class with a 308.You would be out gunned from the get go.
As for FTR-Class,That is Limited to 223 and 308 only.


I shot 168's and they keyholed at 1000. That was the last I did that

Right you are Slamfire. 168 SMK or 168's are banned at anything over 600 yards/ You can run with them to 600 yards after that you ( around here anyhow ) Go with the 155 SMK's or 155 Hybreds or 175 SMK's I don't know any one that used heavier than 175,but you have sparked my intrests now for sure. Been wanting to try the 190 for a while now

[Art Eatman]

I don't remember if it were here or at THR, but a couple of guys were backing and forthing about their '06s with 30" barrels and using the Berger 230-grain VLDs at 1,200 and 1,300 yards for sub-MOA groups.

I don't recall any details, though.

[GeauxTide]

MatchKings for hunting?
308 for 1000 yard hunting?
Negative.

[goredsox]

A really interesting subject to bat around -- I think the variables and percentages are too great with the 168gr MK and I don't think 26" will suffice... if you really want a 1000yd .308 cal hunting/target rifle... I'd mimic the concept of the Palma/F-class rifles. 1:14 twist, 28-30" length and 155gr VLD bullets. The Berger VLD would be my choice.

If you want the rifle more than the project... the Savage 12 Palma is readily available.

My own personal version of this dream is based on 6.5-284 -- however, since 1000 yd range is nearly inconceivable in my eastern mountains... I live out my LR hunting dreams with my .243win on coyotes across dairy farm pastures.

[Bart B.]

I agree with the comments discouraging Sierra's 168 HPMK used at the longer ranges. It's boattail design is the problem. Unless one shoots them over 2700 fps out the barrel, they typically go subsonic starting about 800 yards. The military match round that had this bullet replacing their circa 1925 172-gr. FMJBT bullet soon learned its shortcommings at the longer ranges. After replacing it with Sierra's 175 HPMK, the subsonic issue went away.

And Berger's newer heavy 30 caliber bullets are doing well at the longer ranges. I'd not be surprised to see Sierra change the shape of their HPMK's to compete with the Bergers. But the Sierra's will still do very, very well at long range. . . . .when the right one's used.

There are better cartridges for accurate shooting beyond 1000 yards than the .308 Win. While it can be done, one's ability to judge crosswinds beyond that is the biggest factor. One of the newer non-belted 30 caliber magnums holding more powder's a better choice. But with their heavier recoil, they're harder to shoot accurately.

With the .308 Win. in a 26 inch barrel, a 1:11 twist will handle bullets from 175 to 200 grains easily. That's been done over a few decades with the .308. Heavier bullets need faster twists; 1:10 with 220 grain bullets and 1:8 with 240 grain ones.

[nicknitro71]

The reason why professional and military personnel decided to go with a slower twist is due to gyroscopic drift and the Magnus effect. When a body spins on itself, it creates a whirlpool of air making the bullet drift to the same side of the spin. Also, on right twist, the bullet will drop more and on left twist the bullet will rise a bit (the Magnus effect).

All this comes into play at long distances.

The bottom line is that you want enough twist for gyroscopic stabilization but not too much as not to enhance those side effects, hence the 12 twist because they do not shoot heavy bullets.

Decide on the bullet first, then get the appropriate rifling.

[4runnerman]

To sum this up.
308 and 1000 yards= very do-able to say the least
168 SMK= Bad choice
SMK for hunting= Bad Choice ( Although you would never hunt with a 308 at 1000 yards any how. so we must assume he meant target shooting )

1000 yards and better rifles for this= Yes for sure,BUt if what you have is a 308 go for it ( NOT HUNTING ).

Bart's post is very much in line with reality for sure. His last paragraph is open for discussion though. At 1000 yards from my personnel experience what i have been seeing is the 155 Palma's 155 Hybred's and the 175 SMK's. This is FTR class im refering to.
Most will not go heavier than 175 due to recoil and time back on target. There are a few shooting heavier bullets and doing very well with them.

[Jim Watson]

When my present supply of 155 Scenars runs out, I will likely go back to the 175 SMK. A friend likes the 185 Berger in .308. 10 twist.
I'm a Sharpshooter, he's an Expert.

for hunting and something heavier for long range target

This is the Internet version of the 1950s gunzine "all around rifle."
I don't know about the OP or all the other people with similar ideas, but I, for one, do not want to shoot a match or long practice session with a light or medium weight hunting rifle. Nor do I care to hump a target rifle in the woods.

[bigamehunter93]

ok my friends, here is the bottom line. To settle my bullet debate, today I bought a box of 175 SMK's. 1:10 or 1:12 twist?

[Buzzcook]

1 in 10 will shoot heavy bullets and light ones. 1 in 12 might not shoot heavy bullets.

[Metal god]

Yes 1-10 is better if not best . The heavier the bullet the faster the twist needs to be in all calibers .

[4runnerman]

Second the 1-10 twist of your 2 choices. 1-9 would be the best,but 1-10 wil do just fine. Also if you get a chance try the 155 Palmas too.

[Bart B.]

The often heard claim that a 1:12 twist in a .308 Win. barrel will not shoot heavy bullets accurate is well countered with facts in the link below:

http://riflemansjournal.blogspot.com...-match_04.html

Note the M1 and M14 arsenal match barrels used at the time had 1:12 twists. Lapua 185-gr. FMJRB bullets were used in USN and USAF M1's rebarreled with 1:12 twist 7.62 NATO chambered ones and shot sub MOA at 1000 like the 190 Sierra's did. I've shot hundreds (thousands?) of each in Garands and can well attest to the accuracy they produce.

My bottom line is, a 1:12 twist will shoot 155's through 190's the most accurate. But unless you've got at least 29 inches of barrel, the 155's won't leave fast enough with safe pressures to remain supersonic through 1000 yards.

[kahrguy]

bigamehunter93 To help you cut down on the confussion of the rights and wrongs read this artical . http://www.6mmbr.com/308win.html

I bought a new 788 remmington back in 1978 , maybe. 1-10 twist and I have shoot to 600 yards enought to understand why this low cost rifle was the rifle to beet for light weight factory firearms. I found Lapua 155gr scenar is one of the few that will stay super sonic if you shoot to a 1000 yards also out of shorter barrels. The 308 is streaching it at that distance with out 28 to 32" barrels. Hornadys SST loads make very good hunting ammo too.

[FrosSsT]

MatchKings for hunting?
308 for 1000 yard hunting?
Negative.

+1 The .308 sierra matchking (nor any other .308 bullet) is the tool for a 1000 yard hunting job

[kahrguy]

308 with any bullet and 1000 yard hunding is very foolish. Target shooting is somewhat practical but not long range hunting. Missing yardage by only 50 yards at that distance is a clean miss or very baddly place bullet and that makes for a foolish hunter.
http://www.ultimatesniper.com/Docs/32.PDF

[Art Eatman]

kahrguy, I think he left out the word "not". Typos happen...