Home Forums Hunting & Shooting Custom Rifles & Wildcats .270 barrel twist

My son is building a .270 win on a pre-64 action. He’s probably going to use a Pacnor but doesn’t know how many grooves or what twist to order. He will mainly shoot “normal’ bullets, but doesn’t want to handicap himself if he wants to shoot longer bullets later. Any words of wisdom?

Have a look at Berger’s twist rate calculator and order a twist that will fully stabilize the highest BC bullets available.

John

If he's using Pac-Nor he only has one choice, a 5 groove 1:8 twist. Every thing else is a 1:10 twist or slower.

To use the really long .270 bullets, he may need a longer throat than the standard reamer. He should decide what he wants to use (not what he may try down the road) and tailor his barrel and chamber to that.

I wasn’t aware of that Berger page. It looks very useful. Thank you.

Nice catch. Thank you

I’m really ignorant on what the number of grooves does. I need to dig into this further.

5R 1-8

There's no reason not to go with a 1-8. Normal .270 bullets are unlikely to come apart due to increased barrel twist.

I'll disagree with you on this. I recently owned a 6.5 Creedmoor with a 1-8" twist and I was unable to shoot the light Speer TNTs. With max loads they'd disintegrate in flight. At 100 yards pieces were kicking up dust on both sides of a horizontal 4 foot by 8 foot target "platform." I'd expect a .270 with a fast twist to do the same with light varmint bullets.

I'm considering picking up a .270, with the 1-10" twist, specifically to avoid the limitations with light bullets that the 6.5 PRC, which I currently shoot, imposes on me. Though there are high BC .277 bullets now, the selection is better with 6.5 mm or 7mm and I'd recommend anyone wanting to focus on fast twists and high BC for long range to go with either of them over .277. Let the .270 Winchester do what it does best .. flexiblity. 90 grain TNTs through 160 grain partitions. If someone really insists on going with fast twist in a .277 bore, do the 6.8 Westerner.

I just had a Pac Nor #2, 1:8 twist, 5R put on a rifle. Got the rifle back last week.

Have some 180gr Woodleighs, 175 NBT, and 150gr Badlands bullets to try. I would have zero hesitation running any standard 270 hunting bullets through it. I actually think the faster twist will help 130/140gr mono performance on game.

I used to run 90gr hollow point bullets out of my 270 way back when it was my only rifle. Will an 8 twist tear this bullet apart? Possibly. I will never find out as I have zero desire/need to run that type of bullet out of any of my 270's every again.

Hence why I said normal .270 bullets. I don't consider a Speer TNT a normal .270 bullet. Sure any light jacketed varmint bullet has the possibility of coming apart. Much better tools than a .270 to varmint hunt, IMHO.

It isn't so much about the bullets coming apart, it is about to throat for 175s. if you want to shoot those bullets, it may limit your options with the shorter bullets. Talk to your gunsmith about what bullets you INTEND to run and optimize for that.

1-9 is what I'd do.

Thanks for all the advice. I’ll pass it along and recommend 1 in 8.

Looking at prints the freebore of chambers designed to shoot the long, heavy .277" bullets has a freebore diameter for 0.001" and about 0.100" of freebore length, meanwhile traditional .270 chambers are freebore diameter of
0.0013" if I'm reading it right and 0.080" of length.

Might have been a 5 groove but not a 5R
Most 5R barrels are cut rifled and Pac-Nor's are button rifled

stand corrected

I have a 1-7.5 Krieger I’m looking forward to booting up to something 270 in the future. I have 0 worries about it hurting hunting bullets.

An experienced member here (I won't use his name out of respect) went down this path trying 1:8 and 1:9s and found 1:9 to be the best compromise.

I have had around 15 270’s assembled over many years and have used it on hundreds of BG animals. This was all in search for the ultimate 270.

I found a 1-9 twist 22” .560 muzzle just right. I do extend the throat to match the magazine length of the magazine box. I think of the 270 as a BG cartridge so terminal bullet performance is more important than BC. Likewise, I don’t load varmint bullets.

I have had excellent results with the 130 TTSX and 160 NP for a general purpose hunt or mixed bag hunt. For a single species NA hunt for sheep or mule deer or pronghorns I would pick a 130 or 140 Berger.

The super high BC bullets are great on the ballistic charts but not so great on terminal performance.

A lot of it depends on the typical conditions you hunt in.

I live at 4000' above sea level in Montana, and don't travel as as I used to. About the lowest elevation I hunt at is around 3000' above sea level, but most is above 4000', up to around 7000-8000. I also don't hunt nearly as much at temperatures around zero as I used to.

Have experimented considerably with the newer high-BC .270 bullets such as the 170 Berger EOL in 1-10 rifling twists, and they've shot at least as well as "standard" .270 bullets up to 150 grains, including many of the newer higher-BC 150s. So far the heavier bullets like the Berger have grouped just as well--which is what the Berger rifling-twist formula suggested they might in my typical hunting conditions.

I'm just hoping some high bc medium weight hunting bullets of 135 grain and 140 grain start to come out as a result of the .277 Fury. These will most likely need around 8 or 8.5 twist for stability at sea level and to get the maximum bc from the bullet.

Riflehunter
They exist today!
Find some Federal 136 Terminal Ascents.

It's still only .493 G1 on the 136 grain .270, which is ok but not wonderful. The .277 140 Badlands has a bc of .650 and their 150 .710 - now that's what I call good. A 136 should have a bc of perhaps .550 to be good. But the Federal Terminal Ascent 175 grain in a .308 at .520 G1 might interest me more with a sectional density of .264. Get 'em going at 2700 fps. Then again, the Badlands 175 grain .308 has a bc of .605 which is still a lot better. Thanks for letting me know RinB.

well i know its a little faster,but i have been shooting a custom built 270-300 win mag for about 19 years.its a 1-10 twist broughton 3 contour barrel at 25 inches.it is a small ragged hole shooter with both barnes 130s and nosler accubond 140s.have many rifles but this is all have used for deer to black bear since i got it.

Barnes is now making a 155gr LRX for the 270. Barnes states 1:8 twist. I ordered two boxes, and will give them a try. Going into the reloading room shortly to start putting together some initial load testing rounds.

Starting with the 170gr Nosler Ballistic tips, then will move on to the 155gr LRX and 150gr Badland bullets.

That 155 LRX might be a butt whooper.. I am looking forward to seeing how you make out with it Chad.

A 1:8 270Win @ 22" will push the 140gn Super-BDII to ~3100fps via R-26.

I using Ramshot Magnum for 170gr NBT's. Will see how it works.

Going to using Rel 26 for the 150/155gr bullets.


Thinking the 155gr LRX will be a one bullet do all for my 1:8. Definitely going to give them a run this fall.

I would not have even ordered the Badlands had I known Barnes was going to come out with this bullet.

Chad you’re using the standard SAAMI chamber in your 270 correct?

Yes, and standard mag box. With Magmum powder, plenty of room for the 170gr bullet.

Might run into some compressed powder issues with Rel 26.

This 270 was built as a hunting rifle to shoot heavies and/or spin 130gr monos with higher RPM.

Will post a new thread and pics after the initial range workout.

I have lived with 270s since 19668. I have shot the throat out of 2 barrels and am working hard on a 3rd in one rifle, and have shot several thousands of round through about 7 other rifles.
With all that said I have never found any problems at all with the regular 1-10" twist. If some company was to make 185 or 190 grain 270 bullets there may be a reason for a faster twist. But for what I have used my 270s for up to and including killing horses and cattle on our ranch, I have never seen a problem with 1-10. I have thought about the use of a super long bullet, but the concept is a situation that is so specialized as to slip more into the "what-if fantasy land". It's as if the world wants to ignore the near century of excellent results we've seen from the 270 with 150 grain bullets and find some 'idea" of how it needs to be better.

There are times I want more. In those times I use a 300 mag, or even a 375H&H. I simply can't see a need or even a want for a 270 with a longer heavier bullet. Speer made 170 grain RN bullets years ago and I used some of them and I am very much a fan of the Nosler 150 and 160 grain Partitions as well as the 150 grain bonded core bullets.
To each his own. If someone wants to play with a 270 with very long bullets, so be it. It might be fun. But from results in the field on game killed over 50 years, I have serious doubts that there will be any meaningful gains.

Exactly szihn! My feeling exactly. Holds true for all fast twist bs.

szihn and WCH,

I can appreciate your opinions and thoughts. I have plenty of 1:10 twist 270's. (Seven in addition to the 1:8, plus my son's have three) I have never found them wanting. I have only shot one barrel out, and had I continued to own only one 270, pretty sure that I have burned out more than one.

This is the Fire, and looneyism runs rampant. I figure if my looneyism is down to a 1:8 twist standard 270 WCF cartridge, so be it.

I can expound on the small perceived benefits of the heavier bullets and faster twist for the monos. But it falls under minutiae, angel dust and dancing on pin heads.

Ultimately it comes down to this: I built one because I wanted one.

We have shot critters with 85gr to 150gr bullets, and most everything in between. I am of the firm opinion that the 270 plain works.

If I want to go bigger, I have 338-06's, 416 Remington and a 45-70. Smaller would be 222, 22-250, and 6.5x55.

WyoCoyoteHunter and CRS, I believe we see thing much the same way.
As a side note; My old friend Brad (who I've known since we were in the Marine Corps together,) came to Wyoming last year to hunt antelope. He had made himself a custom 270 on a Savage with a fancy folding chaise stock and a 1-8 twist barrel. He loaded the new Sierra 175 grain Tipped Gameking. Very accurate and flies well, but I was unimpressed. Brad shot a doe antelope in the neck over a cultivated field from only about 30 yards and the bullet was angled towards the center of the chest on the other side. The doe dropped dead instantly but that 120 pound animal was enough to tear apart the bullet into fragments and we found no exit at all. The line from the hit to where the exit should have been was maybe 14 inches. Brad wanted to see on the antelope how the bullets would do and make a decision as to his use for an upcoming elk hunt.
He took my advice and went back the the 160 grain Nosler.

But I am going to guess that many if not all of the new wizz-bang-ubber special, long, heavy 270 bullets are just going to be target bullets and are designed from their inception for flight characteristics and not for real performance on game.
In my life I have made some very long shots, and the longest shots I ever made on both deer and on elk were made with a 270 Winchester, all with 150 and 160 grain Partitions. I don't do it anymore because I don't have to, and I never really had to. I did it because I wanted to --- but in my whole life, in hunting 60 years, in 11 states and in 7 countries, with a game count I lost track of about 40 years ago, not 1 time EVER did I actually NEED to shoot over 500 yards, and I do mean not 1 time, EVER.

Now I don't get upset or angry at those that want to do it, but I guess I outgrew my desire to do so. And even when I was young and did make long shots I never felt any real sense of satisfaction from them. The ones I felt the best about were the opposite. Those I made at ranges under 10 yards, and a handful under 10 feet. Two at under 2 feet.

So I am of the opinion that most if not all of these new long slick bullets are designed to fly well, but the best killing effects for them is not considered by the manufacturers. Brad's bullets are an excellent example A plain Vanilla Remington Core Lokt or Winchester Power Point, in either a 130 grain or150 grain loads would have actually done a better job. All his kills were at 375 yards and less too.
Brad was one of our unit snipers and he is quite skilled at shooting long range. We both like to shoot at 1000, 1200 and 1400 yards and we both do it well. But that's more a military skill. In my hunts I see the game as a blessing from God and not my enemy. I have not shot one at long distance and lost the animal, but I started to think it was only a matter of time if I kept doing it. So I stopped shooting game past 500 yards altogether about 25 years ago. I have never one time had to turn down a shot since I did that either.

I can say from experience however, the standard 1-10 twist made many hits to over 1000 yards very well with 150 grain bullets, (most of which were flat based) and I can't actually see a gap in the performance of the 270 that a longer bullet would fulfill better.

If a standard 270 is not enough I personally would change guns, not just use a longer bullet.

I would not use a Sierra Tipped Game King on anything but targets. Thinking friend would have much better performance with a 170 Nosler ballistic tip, or one of the 150gr monos. In addition to the above mentioned 160 NPt

Longest shot I have ever made was on a doe antelope at 475 yards, 1:10 twist 270 and 145gr ELD-X. Bullet seemed a touch soft IMO, and confirmed when I shot a mule deer with it at 175 yards. Made a mess again.

I like monos, and am thinking the Barnes 155gr and Badlands 150gr will work great, without undue tissue damage. Should have no issues tickling 3000fps with Rel 26. Thinking they will do exactly as I expect them at the intended distances I plan on using them.

Here is the mule deer


For when I want to get really close. I like max helical on my fletching too!

I like the .270 a lot but the gap between .270 projectiles and 6.5 and 7mm in terms of bc is too great to ignore if you need to shoot long-range on some occasions. If you pay a large amount of money and travel to hunt something that you may only hunt once in a lifetime because of the cost, you may be faced with a shot of perhaps 500 yards, or go home without anything. That is why I am looking forward to more middle-weight .270 bullets that have higher bc's and require an 8 twist barrel.

I just ahot a large boar through both shoulders with 175 sierra tgk out of 6.8W and exited. I shoot a lot of pigs wirh different bullets and do not get many exits on large boars unless monos so the seems a pretty stout bullet but ex of 1. For comparison I shot a large boar with Mule Deer’s old Gentry 280 a few weeks ago with 160 Accubond and did not exit. Neither do 180 or 162 hornady interlockts typically exit big boars out of 300/7rm. The BC on the Sierra could be higher I expect but it is a pretty stout jacket on it vs some of the very thin jacketed bullets with higher BC

Lou

Lou 270,
Interesting anecdote on the 175 Sierra. That is not what I would expect from that bullet.

Loaded up some of the 150gr Badlands Precision bullets and LRX's tonight. Tuesday should be a good day to hit the range and run them through the rifle and over the LabRadar.

The Badlands bullets are just about too long for my rifle. Have 5 thousandths jump when seated just past the ogive.

I dropped off a Krieger 1-7.5 .277, action and a McM Hunters EDGE to my smith yesterday.

It’s CRS’s fault

Like Chad, I have and have used 270’s and love them. Bullets like the 155 LRX and 165 Nosler ABLR are sorta what I wanna focus on.

I love being an enabler.

CRS

Badlands look pretty good. Not tried them yet. I have 1-8 twist so probably go 140s though I think the guy said 1-8 ok.

Riflehunter

Plenty of good high bc hunting 270 bullets now. Pretty much every manufacturer offer heavy 277 bullets in their hunting lines now but Hornady. True 7mms and 6.5
Have more high bc match bullets. Some folks like them and more power to them. Personally I would not risk a “once in a lifetime” hunt with a bullet that is not designed for hunting even if little higher bc

Lou

My thoughts exactly. If I want 160grs or 175grs I’ve got 7mm rifles for those.

The .270 may have been about the best tool around for deer size game for 90 years with 130's, 140's and 150's but other calibers on either side now have similar weight bullets that perform slightly better at longer distances because of their bc. For example looking at what Sierra offers in hunting bullets, their 140 TGK 6.5mm has a bc of .563, their 7mm TGK 140 grain has a bc of .545 but their .270 140 TGK has a bc of .508. Surely it's not much to ask for a slight improvement in middle-weight (e.g. 130, 135, 140 grain) .270 bullets so they have comparable bc's. If they made some 140's that work in an 8 twist that have a bc around .550-.560, then that would be better. As it is, there is only one bullet in .270 at 140 grains that has a very good bc- the Badlands SuperBulldozer at .650 and that's a long mono. It doesn't make sense to have bullets that have more wind-drift, more drop and less impact velocity unless you're always shooting at close range.

Seems like it’d just be a lot easier to just use a 280 or 6.5 if long range shooting is what you like doing.

Even at 350 yards, middle-weight bullets with high bc's show an advantage over poor bc middle-weight bullets.

Exactly, the farthest I have shot an animal is 475 yards. Long range hunting does not apply to me. I am a 270 looney, nothing more, nothing less. If I was to start competitive shooting I would re-evalute. But for my needs, I am set.

I stretch my my rifles out to 1000 on our property. But am not too serious about it, nor successful. Out to 600, watch out. Even though I never plan to shoot at a critter that far.

This new rifle is going get some serious LR work, just to see if I can.

General info for those shopping barrels. My preference for barrels, especially their prefit for Remington 700 and Savage Target Actions is the PacNor Super-Match using the PacNor barrel nut, and polygonal rifling. In the .204, .224, .6mm, and .308 these barrels are the most consistent and accurate I have installed. They also foul less than others and clean easily using only solvent and patches. Just a suggestion for consideration.

You do good work

The 155 LRX will drift around 2" less than a 129 LRX at 500 yards in my typical hunting conditions, when launched at speeds that temperature stable powders are capable of sending them (i.e. not Reloader 26). A 129 LRX will already bust through elk shoulders and exit, and both reach that 500 yard distance with enough speed to open, so not sure what all there is to gain from a practical perspective, but building new rifles is always fun!

I have an extra 1-9” Benchmark .277 #1 if someone needs one

Exactly, I have 129 LRX's on the bench too. Along with 130gr TSX, TTSX, and CX's. Might be some 110gr TSX, TTSX, and 100gr CX's if I really want to speed things up.

It cracks me up, I think some folks think you have to use the longer, heavier bullets just because you have some extra twist. 6.5's have had 7 or 8 twists for years and folks have shot everything out of them from light stuff up to the most aero bullets they can cram in them and that's cool. Add some extra twist to a 270 and it's like it'll be hamstrung to one or two bullets..

Yep. If I were to build a 270, it would likely be an 8 twist or faster. Not like I'd be worried about nuking light jacketed varmint bullets, as I've rifles better suited to those pursuits.

More pointing out that the current .277 bullets available for faster twist don't gain much over more common bullets at 270 Win speeds. Like the 170 Ballistic Tip - the BC doesn't make up for the lower speeds. Regarding some of the other choices....I don't know about you guys, but I've not had the best of luck with boutique bullet dealers, so tend to stay away from them until they've been around long enough to establish themselves as a viable business (remember Wildcat bullets?), and let someone else do the beta testing performance on game.

For sure PG, I’m okay with what Barnes, Nosler, Sierra, Hammer and some others make and to be honest I’m not likely to shoot 10 different bullets out of it, more than likely I’ll find one I like that works for me in regards to hunting and use that.

I have a big stash of the old 130 and 150 grain Bitterroots and I have a good feeling the extra twist won’t hurt with how they perform there either with extra RPMs.

But I guess I’m in the camp that since I’m putting a new barrel on the rifle the extra twist won’t hurt anything and opens doors if I’d like to try a heavier bullet as well. Your comparison of 2” at 500 yards between the two makes a ton of sense and since I am a dialer with most stuff over about 250 yards I’ll take the little extra if everything else makes sense as far as wind drift is concerned.

PG,
I understand exactly where you are coming from.

This is not about pragmatism at all. I have shot thousands and thousands of rounds through all my 270's. I could easily live with a 130gr mono seated over 60gr of H4831 for the rest of my hunting. Or a 150gr Hornady Interlock, or partition or..... Looney is as looney does.

I have one rifle that shoots the 145gr ELD-X into tiny groups way out there. Will the boutique Badlands precision bullets be significantly better? I do not know, but will have fun exploring it.

My ultimate goal is not a one rifle/bullet combination that does it all. It is to have fun, try different things.

But I needed a barrel and I thought why not go faster twist. I am not so much about the long range high BC bullets as I am about the heavier bullets at this time. I will certainly stretch them out.

Heavy for caliber bullets have performed for a hundred years. Monos have changed the game a bunch and are my preferred any more.

I am also of the opinion that a faster twist helps monos work better.

When I built my last three 338-06's I went with a 1:9 instead of the standard 1:10. The extra twist has not been a detriment at all, near as I can tell. Especially with 210gr monos I like to use.

I started shoot faster twists around 1988 in 27, 28, and 375. The only way to get one was from a cut rifling mfg. With the bullets then available I had best results with 1-9 in the 27 & 28. I found the 1-8 to be a little fussy with the lighter weight bullets (130-150) compared to the 1-8. I tried several different 1-8’s and they didn’t stay around for long.

In the 375 I used 1-12 and 1-10, which I preferred. In 375 1-8 and 1-9 were not great. I you gave me a 1-14 I would immediately change the barrel.

Today bullet quality is better. If a bullet is slightly unbalanced a fast twist will really give poor results. The Juneke machine has improved core and jacket quality.

Like most everything I concluded one is best served by a balanced approach.

Terminal performance is really changed by faster twist. The tin foil jackets will really come apart.

Here is my new 1:8 twist 270 WCF with initial range report.

New 270 WCF hunting rifle with 1:8 twist

RinB,
I do not foresee any issues with tin foil bullets in my new rifle, it will get fed a steady diet of monos or lead core bullets designed for the faster twist.

I have been using Proof pre-fit barrels for my DIY builds and I'm looking to build another 270 but they don't offer pre-fits for the 270, only carbon blanks. I found their twist offerings interesting, ideally, I'd go with 1:9 but they offer 1:7.5, 1:8.4 and the traditional 1:10. I guess I'd go with the 1:8.4 if I went the Proof route.

135488 22 7.5 2.5" 1.20" Sendero 2lbs-13oz

130513 24 8.4 2.5" 1.20" Sendero 3lbs-1oz

133859 24 7.5 2.5" 1.20" Sendero 3lbs-0oz

105788 24 10 2.5" 1.20" Sendero 3lbs-0oz

I have a 1 in 9 on my .270 and about the only bullet it's ideal for is the 150 LRAB, which I don't use. I would definitely go 1 in 8 if I had my time over.