You see 1-10's, 1-11's, and 1-12's, I had a Rem model 7 in 1-10 that would not shoot much of anything well, 150's to 200's. What twist rates in the .308 match up with which bullet weights? It would seem to shoot 180's or 200's or Barnes bullets you would want at least a 1-11?

I don't think the 308Win has enough case capacity to effectively shoot bullets heavier than 168 grains. When shooting the standard cup and core bullets the 1/10" twist is hard to beat unless shooting the lightweights, for bullets less than 130 grain a 1/11" or even a 1/12" would probably be in order. TO shoot the mono-metal bullets such as Barnes you may want to back off one weight size of bullet because it is really not the wieght but the length of the bearing surface of the bullet that determines barrel/bullet stabilization.

If you want to shoot 180's or 200's buy a 30-06, not a 308.

AD

If your 308 has a 1-10 twist and it's not shooting well the answer is most likely not in the rate of twist!

Sheesh... .308's not shoot...

1 in 10 will shoot 180's and 200's just fine.

twist rate is used best for length of bullet not weight.
this works for cast ond jacketed.

I have owned 5 308's! All of them shot well exept a model 7 remington the old blue one with 18 inch barrel. My point is that some manufacturers (Remington) twist a .308 barrel at 1-10, while Kimber, CZ twists 1-12, Sako 1-11. Someone said if you want to shoot 180's or 200's then buy a 30-06 as the case capacity of the 308 is too small for the heavier weight bullets, that is funny as you can get 2600 out of a 308 with a 180 and 2700 from a 30-06, not that much difference, but the 1-12 twist in the Kimber .308 must just about guarantee that a 180 grain barnes bullet will not fly well? I have noticed people complain about rifle accuracy from time to time where some complaints may have to do with the rate of twist and the bullets used. I am not disputing 308 accuracy, simply that many manufacturers gear the barrels toward lighter weight bullets when there is no need to do so.

Although I use 168s for coyotes, 308s are fine with heavy bullets. The favorite bullet in the 30-40 for hunting was the 220 gr round nose at 2000 fps and it killed exceptionally well; the 308 will out run that by several hundred feet.

I would want 1-10 and never look back.

quote:

Originally posted by tiggertate:
Although I use 168s for coyotes, 308s are fine with heavy bullets. The favorite bullet in the 30-40 for hunting was the 220 gr round nose at 2000 fps and it killed exceptionally well; the 308 will out run that by several hundred feet.

I would want 1-10 and never look back.

That's absolutely correct. I'm almost positive that even the 1 in 12" twist will handle round nosed 220 gr. bullets just fine. In fact, with 44.0 gr. of W-760, I get 2310 FPS and .375" to .50" groups from my Winchster M70 in .308 and it has a 1 in 12" twist. So much for gun writer BS!
Paul B.

I like 1 in 12" myself but that's mostly because the .308 I was loading for really liked the 165gr TSX in that gun (M70 Featherweight). It also shot the 150gr Ballistic Tip very well, it would regularly throw then into .8" or so. The TSX would go .5" to .75" with predictable regularity. 180gr Fail Safe did MOA as well and worked very well for moose and elk for the owner.

the greenhill formula says otherwise, for instance a 180 grain .308 diameter Hornady Interlock at 1.265 inches in lenght requires a 1-11 twist if the bullet is going slower than 2800fps and a 1-13 if going faster than 2800, a Nosler accubond at 180 grains and 1.495 inches in length calculates to require a 1-11 if faster than 2800 and a 1-9 if slower than 2800 fps, I don't know how long a 200 or 220 is but it has to be longer than a 180 and it has to go slower than a 180, so it at least requires a 1-10

I used to be way into the arm chair 308 expert stuff years ago when I bought an FN SPR. I will try and run from memory. Standard twist was 1:12. 1:12 is optimal for 168 grainers. I believe the 1:10 came out for the 173 grain ball match load, which was not all that good a projectile in the 308. I bought 500 before I read that far in the books.
Then came the 175 Sierra SMK, and the folks decided that the best twist rate for this bullet was the 1:11. These optimal differences are for things happening with the bullet when it is crossing the trans-sonic line out around 600-700 yards. Things can get wobbly.
I have shot maybe 250 yards with my FN bolt action with 168 Sierras and 175s. No real difference that I can see. It is more like running a drill press than shooting a rifle. I think a 1:12 is fine. I would think that the 1:10 would steady the big boys allright at any reasonable speed.
My interest in 308 waned appreciably after I got a 338 lapua and a 25-06. 308 is like a lexus, near perfect but short on personality, unless you have a finnwolf, and i gave mine to a buddy as a graduation present.

Based on my experience, I'd prefer 1 in 10, but will take 1 in 11. I have not had good luck with 1 in 12 at all.

Dan

From Chuck Hawks...
Rifling twist rates

The rate of twist, expressed as one turn in so many inches (i.e. 1 in 10"), is designed to stabilize the range of bullets normally used in a particular caliber. It takes less twist to stabilize a given bullet at high velocity than at low velocity. At the same velocity in the same caliber, longer (pointed) bullets require faster twist rates than shorter (round nose) bullets of the same weight, and heavier bullets require faster twist rates than lighter bullets of the same shape. It is undesirable to spin a bullet a great deal faster than necessary, as this can degrade accuracy. A fast twist increases pressure, and also the strain on the bullet jacket.

Fortunately, the rate of twist chosen by the rifle maker is usually appropriate for the intended cartridge. Anyone ordering a new barrel for a rifle will generally do well to specify the standard twist as supplied by the major rifle manufacturers for that caliber.

Once in a great while, though, a manufacturer makes a mistake. One such case involved the .244 Remington. When first introduced, barrels for this caliber were made with a 1-in-12 twist, because Remington anticipated that their new cartridge would be used primarily for varmint shooting. The 1 in 12" twist is ideal for best accuracy with varmint weight bullets (70-85 grains) in a high velocity .24 (6mm) caliber rifle. The heaviest spitzer bullet that a .244 with a 1 in 12" twist barrel could stabilize was 90 grains. The customers, however, also wanted to use their new .24 caliber rifles for hunting medium size big game, with 100 grain bullets. Needless to say, customers ignored the new .244 Rem. Remington soon saw the error of their ways, and changed the rifling of their .244 barrels to 1 turn in 9", but the damage was done. Sales remained so slow that eventually Remington had to discontinue the .244. The following year they reintroduced the exact same cartridge as the 6mm Rem., and produced all 6mm rifle barrels with 1 in 9" twist barrels, which can stabilize all .24/6mm bullets. This solved their marketing problem, and 6mm rifles began to sell.

The usual twist rates for some of the more popular rifle calibers are given below. (For a more comprehensive list, see "Common Rifle Barrel Twist Rates" on the Rifle Information Page.)

.22 Short = 1 in 24"
.22 Long Rifle = 1 in 16"
.223 Remington = 1 in 12"
.22-250 Remington = 1 in 14"
.243 Winchester = 1 in 10"
6mm Remington = 1 in 9"
.25-06 Remington = 1 in 10"
.257 Wby. Mag. = 1 in 10"
6.5x55 Swedish Mauser = 1 in 7.5"
.260 Remington = 1 in 9"
.270 Winchester = 1 in 10"
.270 WSM = 1 in 10"
7mm-08 Remington = 1 in 9.25"
7mm Rem. SAUM = 1 in 9.25"
7mm Rem. Mag. = 1 in 9.25"
.30 Carbine = 1 in 16"
.30-30 Winchester = 1 in 12"
.308 Winchester = 1 in 12"
.30-06 Springfield = 1 in 10"
.300 WSM = 1 in 10"
.300 Win. Mag. = 1 in 10"
.300 Wby. Mag. = 1 in 10"
.303 British = 1 in 10"
.32 Win. Spec. = 1 in 16"
.338-57 O'Connor = 1 in 10"
.338 Win. Mag. = 1 in 10"
.35 Remington = 1 in 16"
.350 Rem. Mag. = 1 in 16"
.375 H&H Mag. = 1 in 12"
.416 Rem. Mag. = 1 in 14"
.444 Marlin = 1 in 38"
.45-70 Govt. (Marlin and Ruger rifles) = 1 in 20"
.450 Marlin = 1 in 20"
.458 Win. Mag. = 1 in 14"

Not all rifle barrels of the same caliber have the same twist rate. A fellow ordering a custom rifle may have his own ideas about twist, as may the builder. For example, some .270 Win. barrels are rifled with a 1 in 12" twist, some .30-06 barrels are also rifled 1 turn in 12", and some .300 Magnum barrels are rifled 1 turn in 14". Usually these variations make no great difference. These slower twists may give slightly lower pressure, as well as very slightly better accuracy with the lighter bullets in each caliber. They will still stabilize the heavy bullets over practical hunting ranges. However, they might not be such a good choice, or quite as accurate, for shooting heavy bullets at extreme range (like 600-1000 yards).

Steyr makes the SSG's, tacticals and scouts w/ a 1-12" twist and factory test with 168 gr GM308M ammo.

They also produced an interesting special version of the Scout for sale in Switzerland where some Cantons mandate a minimum 20" barrel. This particular model is fitted with a 20" (50.8 cm) barrel with a 1:10" (1:25.4 cm) twist and its muzzle is threaded to accept sound suppressors which are legal for Swiss citizens to own. The 1:10 twist allows the stabilization of 200 and 220gr sub-sonic loadings.
Limited firing with 1:10 twist rifle yielded the same sub-moa capability as the standard version using Federal 168gr Match ammunition, but it is really designed for optimum performance with the longer 200 gr and 220 gr bullets.

I wish I knew how copy right things went because I have an old Guns & Ammo article I would scan in that would put this discussion to bed.

This author had a barrel maker make him barrels with identical outside diameter but with different rates of twist from 1-8 thru 1-14 but in 30-06. He used identical proven "average" accuate handloads for each barrel, then shot them with bullets from 110 grains to 220 grains just to discover the "best" rate of twist for .30 rifles. The chart showed it was a toss up between 1-10 and 1-12. The 1-10 shot bullets heavier than 200 grains better, while the 1-12 shot the lighter bullets just a little bit better. The bottom line was if you were going to go above 200 grain bullets, go with the 1-10. If you were happy with 200 grains and below either would do with a slight edge going to the 1-12.

hacksawtom,
You are correct but then look at the length of a Barnes copper bullet! I think a lot of this goes out the window with the long copper bullets and you are better with a 1-10!

quote:

Originally posted by Jimmy P Coaltrain:
the greenhill formula says otherwise, for instance a 180 grain .308 diameter Hornady Interlock at 1.265 inches in lenght requires a 1-11 twist if the bullet is going slower than 2800fps and a 1-13 if going faster than 2800, a Nosler accubond at 180 grains and 1.495 inches in length calculates to require a 1-11 if faster than 2800 and a 1-9 if slower than 2800 fps, I don't know how long a 200 or 220 is but it has to be longer than a 180 and it has to go slower than a 180, so it at least requires a 1-10

That's the problem; a formula is just a formula. Scientists once said that it was impossible for the Bumble bee to fly, yet it does. Igt was also said that the old C-124 Globemaster couldn't fly with a full load, yet I've seen them take off with a full fuel bowser on board.
Formula or not, my Winchester M70 has a 1 in 12" twist and it shoots 220 gr. Sierra bullets into very nice tiny groups. I might agree that 220 gr. bullets in spitzer form might not work, but I've never seen the need for them in anything I shoot.
My custom 30-06 built by the late Cal Albright also has a 1 in 12" twist and it shoots those 220 gr. Sierras just fine.
Formula or not, the empirical evidence seems to prove otherwise.
Paul B.

and so that is fine Paul it works on your rifle, however a man betting on a new gun could be as lucky as you are or it might not work I trust math and statistics over maybe's. I am going with a 1-10 so I don't have to worry about it.

Well I just gotta put my thoughts and observations in here as well. A few years ago I bought a .308 customized for someone else for target shooting. It has a(Hart)bull barrel that is 23 inches long. I found a Rem 40X target stock and had Garland @ Triple G in Stephenville,Texas do the pillar block bedding. This rifle will put boxes upon boxes of 168s(Federal match) into a ragged 3/8 hole at 200yds. Same with 125Corbons. I feel a 308 is at its optimum with 168gr bullets. Yes I have used 180s and 200s in the past with great success. I am sure to get hate mail for hunting with match bullets. When I squeeze the trigger and BANG-FLOP, it makes the point a mute one.

Not sure what point I was trying to make(brainfart) but there you have it. I have 5 other .308s. With twists varying from 1-9, 10, 11, 12, and a gaintwist that seems to be magical. I still don't completely understand the gaintwist. I just know all the rifles from here out will probably wear gaintwist barrels.
Andy

Length not weight is what determins a bullets suitibility for a certain twist. velocity plays a role as well.

drew
I have a gain twist bbl on a Match M-14.

The theory on a gain twist barrel, is that the bullet starts out with a very slow twist, which lessens the pressure as the bullet enters the rifling. by the time the bullet exits the barrel it has the proper twist to stabilize it.

Theoretically, higher velocity should be possible with a gain twist bbl. Also less bullet deformation and longer bbl life.

Some German Artillery had gain twist bbls in WWII.

gain twist is very interesting.

I think 1-12 is fine with all standard lead core bullets but I bet a Barnes 180 would be very long!!

My only experience with a Mod 7 was one of the first 20" SS versions that I played around with and hunted with in 1996. We really battled to get that rifle to do anything under 2" at 100. I remember 165gr partitions being the most accurate we tried.

Could have been us, but we had other rifles in various calibres shooting well with our loads.

I am surprised some folks think that 180gr is too heavy for the .308? Thats all some bushveld .308 owners shoot, and it works really well...

My modle 70 shoots one hole with 5 shots with 168 Grain Amax bullets. I belive it has a 1-10 twist. By the way not one coytoe shot with this load has taken a single step. It is devistating!!

I tested this rifle with bullets from 150 to 180 grains. The 168s were it!!!

Jimmy, make sure your stock is relieved all around the barrel. Take a handkerchief and if it cannot be run all along under your barrel (like you shine your shoes), then your stock is too close to the barrel, affecting the harmonics & accuracy.

I bought a Remington 700 with heavy barrel & synthetic stock that needed work with a Dremel tool, before it would shoot accurately......also a .308.

Jim