If your wanting to hunt only 165 to 168 grain .308 deer bullets what would be your preferred twist for a custom barrel?
Thanks in advance

Call the barrel maker and ask them, you may be shocked.

10 twist is your huckleberry.

For 30/06, I use 1 in 12.Rick.

1-10"

Finally I get to agree with Steelhead about something, 1-10"

Damn, 8 years plus of stupid.

Without a doubt 1-12 twist. It will stabilize 180's with possible exception to VLD's. 1-10 is faster than needed in most all 30 cals. 1-11.25 will do about everything.

Here's a blurb right off of Shilen's website...I think they underrate the 12 twist though as 180's will do fine in the 12.

.308
- 7" * for heavy VLD bullets and/or subsonic ammo.
- 8" for bullets heavier than 220 gr.
- 10" for bullets up to 220 gr.
- 12" for bullets up to 170 gr.
- 13" * Ratchet rifled 4 groove
- 14" * for bullets up to 168gr.
- 15" * for bullets up to 150 gr.
- 17" * for bullets up to 125 gr.

Compelling.

And what would be the downside to a 1-10 in a hunting rifle, ace?

A 1-12" is akin to buying a vehicle with a towing capacity of 2000 pounds because your trailer weighs 1,995 pounds.

None to speak of, just that I've had some 12 twist custom barrels that just shot so incredibly well in that range of bullet weight that it seemed to be a great match. It is said it's no big deal to have an over stabilized bullet, but also that you may gain some velocity with a more suitable slower twist... For me there's no question in a 308 Win/30-06 sized chambering where I'm not going to shoot 200gr bullets...If given the choice I'll use a 1-12. That said if my barrelmaker had a 1-10 on hand and I would have a wait on the 1-12 I'd probably spin on the 1-10.

It's a myth that any significant velocity is gained with a slower twist, but recent research has shown that a faster twist will result in a higher BC if the "over-stabilized" bullet has a stability factor (Sg) of 1.5 or over. And some 168-grain .30 will not get to 1.5 with a 1-12 in some conditions.

I have yet to own any .30 caliber from .308 Winchester to .300 Weatherby with a good 1-10 twist barrel that didn't shoot 165-168 grain bullets very well.

All Sako .30 cals use 1:11, so I don't argue...;)

Works for me...

FYI, my 700 308 Varmint with a 12 twist spun 190 SMK's just fine.

Also, Msalm has been around more than his share of 308's.....

I'm pretty sure a 190gr SMK would be my first choice in a hunting bullet.

1-10"

Point is, the 12 spins a 190 just fine, and he ain't going there.

11.25" Rock.....

The Sierra 190 is designed to work in a slower twist, but a 1-12 won't fully stabilize a 168 Berger VLD, 165 or 168 Tipped TSX, or even a 165 Nosler Ballistic Tip in all hunting conditions. And yes, Bryan Litz's latest research demonstrates that it's better to over-stabilize than marginally stabilize.

such as John ?

Nough said!

RD,

When it's really cold.

The OP's question was about hunting rifles, not target rifles. We can probably assume it will be shot in different conditions than the average target match, and might just be shot with different bullets.

That was the reason I asked John because you named the 165 BT and I happen to own a Hart barreled custom Husky that I shoot mostly in cold weather and have had pretty spectacular accuracy with. Not talking about minus 0 cold when developing a load.

As I noted earlier, Bryan Litz has found that while accuracy can be good or even great, when a bullet isn't what many would consider "over-stabilized" then BC is reduced, sometimes enough to make a difference at longer ranges, and certainly enough to make a difference in wind-drift. He's come to the conclusion that a little too much twist is far better than the "minimal ideal" twist.

But whatever. All he done is work for the U.S. Air Force on missile design, thanks to his aerospace engineering degree, been the head ballistician at Berger, started his own company to scientifically study rifle ballistics, and shot on the U.S. Palma team.

Wasn't doubting you John. Just trying to learn something new.

The mystery to me is why some rifles seem to be more accurate with one weight of bullet, while another barrel of the same make and twist will do better with a different weight bullet.

I would like to believe it is science, or something that could be adjusted like twist rates that could give a guy a better probability of an exceptionally accurate rifle with the bullet weights he has in mind. But it does seem like it is part mystery, part science, and part luck.

Throating, seating, ogive type of the bullet and bullet length all play a role.

I will say I've never seen a 30 caliber rifle bughole a Speer plinker or the Remington Accererators, regardless of twist.

1-10 for a 308....because eventually the 165-168's get ditched for 175-178's....

Very good statement, John! Probably went over the heads of most.
The key words were "at longer ranges". Bullet yaw due to over spinning decreases B.C. at shorter ranges, as you stated.

Guys shooting the 30BR in benchrest shoot a 1-17 twist that is appropriate for the 117-125g bullets that are VLD's.

Check out Berger's site as a listed for their minimum recommended twist rate for their bullets:

http://www.bergerbullets.com/products/hunting-bullets/

My custom 308 had a 1-12 twist and it would shoot tiny groups with all bullets up to the 168g range that was available back then, which agrees with Berger's Minimum twist required. I also worked up loads for the 180g Sierra BTSP and the 180g Hornady BTSP, accuracy again was fantastic.

The poster started this thread wanting to know what was the best twist for 165-168g HUNTING bullets, does not sound like he is a long range shooter, does he?

A 1-14 twist might be appropriate for him if wants to shoot Nosler, Hornady, and Speer cup and core bullets. Also, as you jack up the RPM's on a bullet, cup and core bullets are more likely to shed their jackets quicker. I saw this on predators and smaller varmints when going from 1-14" and 1-12" twists to a 1-9" twists in 22 caliber and 243 caliber bullets. I also found that slowing down the twist rate can also lower pressures, which can allow you to get more velocity. Every barrel is different, and there are no absolutes.

I put a 1-11 twist on a custom 7 STW that has zero freebore and a minimum SAAMI spec chamber, the velocity in this barrel is so fast checked with an Ohler 35P, I will not speak of it.

If a guy does not know what he may want later on down the line, then an appropriate twist rate for the Heavy 200+g bullets VLD target bullets would be a prudent decision.

The standard 30 caliber 1-10 twist has been a tradition for a long, long time. After Remington got busted on putting a 1-12 twist in the 244 Remington, effectively killing the new cartridge, everyone wants to over twist a barrel, just in case...safer to go to a 1-8" twist, just in case he wants to shoot a 240g VLD.

I figured there would be strong opinions on both sides. The Rock 11.27 Twist aalf speaks of will work for most all practical .308 bullets, current twist of many precision rifle and replaced the 1-12 of the old M40 sniper rifle. Litz's work on stabilization factors and bc is more than very interesting. But how much more drop or drift one would experience at normal hunting ranges would still be minimal and not sure one would notice it when the rifle shot bugholes. Not saying the 1-10 wouldn't either, but a buddy of mine makes a hell of a 12 twist .308 barrel and with the exception of my long range 300 RUM, I'd use that given the choice. Well not totally true, I am building a lightweight 300 Win Mag for elk on a Pierce Ti action and I will go with a little faster twist to shoot the 200gr Accubond. Just my opinion and I'm just a small time (nobody) rifle nut.

Spinning a 190gr SMK ain't the same as spinning a 168gr TTSX.

Do they teach stupid in Wisconsin? I've had 1-12" 30/06's, I'll never have a 1-12" again.

Agreed, it's a [bleep] stupid decision.

"Do they teach stupid in Wisconsin? I've had 1-12" 30/06's, I'll never have a 1-12" again."


Steelhead, so what were the issues with your 1-12 30-06? Barrel/rifle etc? I'm going to try the 168gr TSX mentioned above in a 1-12 308 because now I'm curious....I did say curious, not butthurt enough to to start name calling.

Barnes does recommend 1-11 for that bullet (just checked their website) so I'll try it in both, 1-11.27 and a 1-12. I am curious...I don't consider myself stupid by any measure.

Issues where that it would stabilize a bunch of the bullets I wanted to use in it.

The fact that you boys are spouting 1-12" without actually ever used a 1-12" with HUNTING bullets is some funny shiet.

190gr SMK, really? Bullets aren't getting shorter and I've NEVER had a problem making a 1-10" 30 caliber shoot everything well.

Again, we are talking HUNTING rifle. Extra twist will always trump JUST NOT ENOUGH.

And I'm not butt hurt, just tired of folks that don't know offering suggestions on what they don't know and wearing the don't know like a badge of honor.

Again, comprehension......

I never suggested a 12 twist, it was a point of interest on the 190's.

My choice was a 11.25", and I built one on it...your's a 10"...deal with it.

aalf,

While I have nothing but respect for your experience, why go as slow pass possible, or refine twist down to 1/4", for a HUNTING rifle? Especially when there is no downside to a 1-10" for the OP's purposes?

Right now I'm working on a article an article on "over-engineering" for a well-known periodical that basically specializes in hunting rifles. I'm going to discuss a lot of things, including triggers, magazines and safeties, but am now going to add rifling twist to the list, because this thread is a perfect example.

John,

In reality there's nothing wrong about going 10, but the OP never really defined his cartridge, what was his intended "deer" bullet/s were going to be, the terrain, comfortable/average shooting distances, etc. Although he's from Tx, it still leaves the questions, whether you assume a tower blind over feeders or not. Kinda like asking "I'm buying a new truck, what trailer should I buy"?

As to "down to the last 1/4", for years, Rock's standby twist is a 11.27", just by design of the gearing on the Pratt and Whitney machines.

While somewhat relevant to most loonies, accuracy is the is the defining barometer of a new barrel/build. So while Litz says over spinning has no downside, in reality, matching the twist to the bullet yields the best accuracy, a proven fact.

A lot guys don't have the knowledge, desire, ability, or platform to milk the best accuracy from their firearms, so the differences could never be utilized anyway.

I've changed my views on this due to Litz's research. I used to be in the camp of optimizing twist to the bullet weights I was going to shoot but now think the increased BC of a faster spinning bullet is going to benefit me more down range than a .1" smaller group at 100. I have an 8.5" twisted .260 and a 12" twisted .308. Both shoot very well with any bullets I care to put in them, up to 140gr VLDs in the .260 and up to 175gr VLDs in the .308. In fact, my best 10 shot group from my .308 was using 168gr VLDs. This one measured .662 MOA for 10 shots at 100m:



Even with the slower twist shooting this well for me, with the quality of bullets nowadays I highly doubt that spinning them too fast is a concern. Next time I'll be going 8" in a 6.5 or 10" in .308.

John

Well, he's partly right. A 1-12 will handle most lead-cored bullets up to 190 grains, but it's right on the ragged edge of even stabilizing at all for a 168 Tipped TSX in colder Texas hunting temperatures, say 25 degrees. And in a 1-11 twist a 190 Berger VLD will be leaving some of its BC behind at that temperature, even if it's very accurate, so would be more susceptible to wind-drift.

So whether the OP is shooting deer at "normal" ranges with something like a 168 Tipped TSX, or wanting go longer with a Berger VLD, a twist slower than 1-10 isn't any advantage.

Have you read any of Litz's research?

I've been thinking 1-8" twist just in case you want to thread, suppress, and go subsonic! I'm sending off an action and barrel (Brux 1-10") to do up a 308 with a 16-1/2" barrel just to be a suppressor host. I'm now wishing it was a 1-8". But the 10 twist will be fine with 208 A-Maxes and I can take those subsonic if I so desire.

I would never go less than 1 in 10 twist in 30 caliber.

1-10 out of a 30 cal is like peas and carrots, covers a lot of ground.

Another popular twist is the 1-8" with a 223 AI shooting the 75g A-Max, hands down winning combo. 1-9" twist is border line on a good day with the 75g A-Max, while the 1-8" twist is spot on perfect.

However, since I could go to 90g 22 caliber bullets in my 223AI and 22/250 AI, why should I not put a 1-6 twist on my rifles to accommodate the 90g? Answer: The 1-8" twist is perfect of the 75g A max, that's why!!! I don't have any intention of ever shooting a 90g, but maybe I should go ahead and order 1-6" twists just in case I really don't know what I want.

Until the OP says what bullets he wants to shoot, it's all speculation on "what if's".

Barnes doesn't put a twist limit on the 165 TTSX, but puts an 11" on the 168's because it's a longer bullet designed to not be mag restricted like the 165's are, and 190 Bergers weren't part of his question.

And no on Litz's writing.

I've never had to read anyone,to see WTF one of my barrels would and would not do,either.(grin)

I've 308's in 10,11.25/27 and 12".

Hell...I even shot one once,in the cold to boot.

I reckon you've shot about 100x more good barrels than poor MD has ever Pretended to Imagine and that's my being charitable.










VERY [bleep] charitable.

Got a 8" on a 300 Blackout and shoot 110 TTSX supersonic and 220 BTHP subsonic in it. But velocity is not on par with a .308.

aalf,
My first preference is the Nosler 168 BT, after that it wouldn't matter that much between the 165 BT or 168 TTSX.

There was some mention earlier about cold conditions. Sometimes I do hunt in Alberta, Saskatchewan, Kansas and northern Missouri. It can be cold in late November in some years.
Thanks,

I used Berger's twist calculator...http://www.bergerbullets.com/litz/TwistRuleAlt.php...and determined that for the 168 Nosler Ballistic Tip, achieving a 1.5 stability factor at 0 degrees and 0 feet altitude (worst case scenario for stability), assuming 2900 fps, requires an 11 twist.

With that said, I have a synthetic stocked, go anywhere, hunt anything 30-06. It has a 10 twist barrel. If I were going to hunt low elevation in cold weather I would want a 10 twist.

I have another 30-06 on the way. It might be done next year. I'm hoping for a beautiful wood stock, nice bluing, etc. It has an 11 twist barrel, but I don't know that I would reach for it first when the weather is miserable.

I would add it's a damn miracle that any animal has ever died after being shot by a 25 caliber rifle. According to the twist calculators 25 cal bullets are basically tumbling by the time they strike a target.

Never known a 10 twist to be a bad thing in a 30, 12 if shooting score, but off the bench you may never know the diff.

Let's see impact test on ballistic media to see what bullets hold nose forward, that is what matters more to me, a hunter, not a comp shooter. I want a bullet to stay in a straight line regardless of what it hits en route to and thru vitals.

I didn't think about magazine restrictions, probably 165's would be better for me.

I don't think of myself as a long range hunter, but I do practice on targets out to 400 yards. The most likely place a really long shot on deer could occur where I've hunted would be in northern Alberta up in a tower blind looking down right of way cuts through the timber. You could theoretically get a shot as far as 600 or 700 yards, after 6 trips to Canada and 4 deer all of my shots have been less than 250 yards.

This has been an interesting thread with a lot of knowledgeable people and I'd like to ask a dumb question about cold weather hunting from a southern guy. This past season in Sask. I was in an enclosed box blind with temps around -25f. I noticed my rifle barrel propped in the corner had accumulated a rather thick layer of frost on the barrel. Probably moisture from my breathing, I didn't think of checking it then to see, but if this frost was also inside the barrel would it effect accuracy or would pressure in front of the bullet blow it out of the way?

Fast twist barrels aids in straight line penetration.

Do a 1-12" and you will leave a BUNCH on the table.

1-8" ain't LESS twist than a 1-10".

Frost on the inside of the barrel does leade to rust in the inside of the barrel. I have bought a lot of used guns for the actions only and it is amazing how many of them have surface rust in the first inch of the barrel(walking with the muzzle up in the rain).

When the hunter comes home from his hunt, he brings his gun in the home where it is warm, rust develops very fast especially if he puts it near the fire place.

Exactly

Its a proven fact that your nuts will dry up and fall off if you go with anything other than 10 twist...

What if you're a chick? I mean.....I ain't, but we don't need to discriminate! (I'm a f'in poet!!)

Yes�... "If my aunt had balls, she'd be my uncle"?!?

This squirrels rifle was 11.25 twist, so bad juju can happen.