fast twist 270 Winchester

[assasinator]

yes i agree. get it throated for the long 175 bullets. keep the relative freebore IMO. i am seating 150 ABLR where BT just impedes past the neck. obviously the 165,175 are seated deeper, but it still saves powder room. i am sure i will get it rechambered to either 338-270 or 270bee. time will tell.

8 or 8.5 twist seems to work for most. i went with 7 because of the 277 sig. does. i have 140gr ablr in the mail to see how they shoot shallow seated. the ogives are what have given me fits....
175 TGK have a relatively short ogive, and a VERY long bearing. ABLR have a steep ogive. 170 bergers have the best tangental ogive and really have a long jump to my rifling. i gotta get them figured out.

i talked to a sierra engineer, and the 175s were designed strictly for the 6.8 western. they DRAG. i got the pressures down, but it took careful loading.

 

[assasinator]

changing to the long 277s is not as straight forward as i had hoped. be careful.

 

[Rule 303]

yes 6.8 western has opened up the 270 world. my 270win is ONLY for 140 and heavier.

i am limited by 308 magazines unless i load a round by hand so i have to use 358 WSM. 35 cal is awesome.

It is a very good good round.

 

[AWLee]

I’ve got a 9 twist and a 8 twist.
I think the sweet spot is going to be in the 8.4-8.7 range for balance of accuracy, pressure, velocity.

If a rifle manufacturer would pair up with a ammo manufacture to work on development of faster twist barrels and higher BC bullets for the upcoming century mark of the .270 Winchester, it would spur a whole new generation of excitement and sales.

 

[Bob Nelson 35Whelen]

i am always considering 270 weatherby shallow seated. may rechamber at any time lol. have dies, brass, etc on hand.

i also have 257 weatherby brass,dies, etc resized to 338/270 lol. gotta get the chamber cut long to clean up the win case cut. always thinking.


building a ar10 also lol. got a magnum BCG and getting a freebored 358WSM made in colorado soon. X shots of 358. my favorite caliber.

@assasinator Glad to hear .358 is your favorite caliber. Get a Whelen and load it to its potential, you will be one happy little Vegemite. Plenty of good posts here on how to get the Whelen performing.
Bob

 

[Bob Nelson 35Whelen]

A standard 1 in 10 twist will stabilize most 150 grain 270 bullets but start using 160 grain or heavier and you can run into stability problems. Is it the new 6.8 Western is made to shoot 165 grain or heavier and uses a faster twist

Assasinator I have a 35 Sambar what one of the original versions of the 358WSM was called. It was my favourite cartridge but it is now my second fav. it has been superseded by a 358/338RUM all have a good length of free bore.

@Rule 303 That 358/338RUM will have some get up and go mate. It would be ideal for the 275gn and 310s. I have now managed to get 2,544fps with the 275gn and 2,455fps with the 319s out of the Whelen SAFELY so yours will be screaming.
Bob.

 

[colorado]

I did a 270 WBY with 1-9 twist. Had free bore removed. Just getting it going but it’s looking good with 170 Berger.

Nice! Please keep us posted

 

[assasinator]

so i took my 27" 7 twist long throated 270 win to the range for a zero session. i put a Meopta 3-18 56mm 30 tube scope on it.

the loads were 150 ABLR and 47 grains of win 76 ,with a 3.44 and 3.54 coal. the barrel has .500" freebore.

both coal loads had the same powder charge. as expected the 3.44" loads were spraying pretty bad at 100 yards. 1.75" shot 15 rounds to get the scope zeroed to 100.

shot 5 rounds with 3.54" coal and it shot .2" center to center 3 out of 5 rounds. the barrel was pretty hot and i expected a few fliers for the longer coal. it was still 1" center to center for all 5.

remember that even at a 3.54" COAL there was .300" freebore (throat)

 

[assasinator]

i used the 150 ABLR bullets because they are long enough to get closer to the rifling AND there are Nosler published 'most accurate' loads. they publish 46 grains of Win 760 as a most accurate load for that bullet. i have a bunch of different powders to include win 760 and 748 so i used 760. i did add one grain for 47 grains. no pressure signs and the accuracy really responded to getting that bullet closer to the lands.

 

[assasinator]

i have 24n41 powder for the 175 sierra TGK and 170 bergers and a coal of 2.54 or longer. with the bullets so shallow seated there is a lot of powder room. it's gonna take care to get this gun to use the new .277 bullets to work and get the speed where i want it.

 

[Red Devil]

Am again looking into a Pac-Nor 24" stainless R5 1:8 twist Bbl. in .270 Winchester, throated for the Nosler 150 gr. and 165 gr. ABLR.

The M700 has a 3.6" magazine, so it should be easy to keep the bullets out of the powder.

A dedicated 9.5 lb. long range hunting rifle.




Red

 

[Red Devil]

Fast Forward Seven Months...

The U.S. Military as adopted the .277 caliber.

And this from BROWNING:

X-Bolt Speed LR

26" Bbl./7.5T/.270Win.

Elegant solution.

Will this become the Std. .270Win for the 21st Century?




Red

 

[Don458]

Fast Forward Seven Months...

The U.S. Military as adopted the .277 caliber.

And this from BROWNING:

X-Bolt Speed LR

26" Bbl./7.5T/.270Win.

Elegant solution.

Will this become the Std. .270Win for the 21st Century?




Red

I just watched this on R Spoomer show where he did a comparison of the 270 w ordered loads

Fast Forward Seven Months...

The U.S. Military as adopted the .277 caliber.

And this from BROWNING:

X-Bolt Speed LR

26" Bbl./7.5T/.270Win.

Elegant solution.

Will this become the Std. .270Win for the 21st Century?




Red

I was just watching Spoomer talk about this and comparing current loads to using the long heavy bullets that a fast twist would offer. Long story short, the case capacity of the 270 can not get the 170 grs velocity up to where it should be to make a difference. Of course Reloading and testing to get peak performance in the rifle

 

[Red Devil]

I just watched this on R Spoomer show where he did a comparison of the 270 w ordered loads

I was just watching Spoomer talk about this and comparing current loads to using the long heavy bullets that a fast twist would offer. Long story short, the case capacity of the 270 can not get the 170 grs velocity up to where it should be to make a difference. Of course Reloading and testing to get peak performance in the rifle

With enough RL-26, one could get a brick to Mach 3.

8>)

Think that the 150 gr. has always been the .270Win sweet spot.

Shoot a lot of Speer Grand Slams in that weight.




Red

 

[Inline6]

I need a faster twist barrel on my 270 Bee. I'm shooting 150 ABLRs at 3300 fps

Usually the higher speeds will help stablize a heavier bullet in a slower twist barrel. You can always run it through Bergers stability calculator if you really want to see how it compares.

Personal preference, I tend to go with a faster twist. New bullets are always coming out so I try to take that into account. My match rifles well that doesn't really matter. 6-8 months it's time for a new pipe.

 

[Ray B]

My friend, the late Bill Steigers (Bitterroot bullets) was a strong advocate of light for bore bullets spun exceptionally fast. His favorites were 130 gr .277 & 250 gr .375. The 270 had a 1-8 twist & the 375 had a 1-9" the idea was that the bullet would openup * peal back into a ball. the fast spin kept the bullet point forward as it traveled through the various densities of the animal.
It worked quite well for Bill and his lighter bullets but the fast spin would be also effective with heavier bullets.

 

[colorado]

I love the 270 Win, but cause i'm a Dad, gave my favorite rifle a BDL in 270 Win I bought in the late 60s to my son. Shoots 150g Partitions at 3000 fps with my handloads. So I bought a well used 270 Weatherby Mark V. Shoots 150g bullets at 3250 fps, very accurate, but am thinking of having a 1 in 8" 26" Krieger or Hart barrel installed so I can shoot heavier bullets.

 

[Red Devil]

I just watched this on R Spoomer show where he did a comparison of the 270 w ordered loads

I was just watching Spoomer talk about this and comparing current loads to using the long heavy bullets that a fast twist would offer. Long story short, the case capacity of the 270 can not get the 170 grs velocity up to where it should be to make a difference. Of course Reloading and testing to get peak performance in the rifle

View attachment 534883

Think ole Ron's MV numbers are maybe a coupla hundred fps low on the 165 gr. ABLR, especially w/ a 24" Bbl., and right at the top for the 150 gr. (which may or may not stabilize in a 1:10 twist Bbl.).

At ~ 2900 fps, the 165 ABLR should exceed 2,000 fps/1,500 ft-lbs for 20" drift at 600 yards.

Woof!




Red

 

[Rule 303]

I love the 270 Win, but cause i'm a Dad, gave my favorite rifle a BDL in 270 Win I bought in the late 60s to my son. Shoots 150g Partitions at 3000 fps with my handloads. So I bought a well used 270 Weatherby Mark V. Shoots 150g bullets at 3250 fps, very accurate, but am thinking of having a 1 in 8" 26" Krieger or Hart barrel installed so I can shoot heavier bullets.

I would leave well enough alone. A 270 150grain bullet at 3250 fps is no slouch and on the slightly heavy side for the 270Cal. A new barrel is an unknown factory. It might be a slow barrel so you don't get the same velocities and/or it might be nowhere near as accurate as your current barrel. Just my thoughts on the subject and probably worth what you paid for them 0.

 

[colorado]

Good points!