270 WBY Mag to ?

[C.O. Shooter]

The 6.5/270 wby mag sounds interesting! I may have to do some research for some data!

 

[backwoods83]

Doing a 6.5x257wby is the same as a 6.5x270wby except your expanding the necks .007" instead of necking them down .013". If you have a bunch of 270wby brass then use it, if not you will only be working 257 brass about half as much. It is a good choice, its like adding a 150 fps to a 264wm and still having the barrel last longer because of case design!

 

[Buffalobob]

You can use the 300Wby case necked down to 6.5 and get some real zip out of it. There are reamers for it.

 

[Trickymissfit]

The 257, 270 and 7mm wby's are all the exact same case. So you can interchange any of those with your magazine and bolt throw the same as it is now.

It depends on what you want to do with it. For a lights out flat shooting deer rifle to 650 yards or so it is hard to beat a 257 wby shooting a 100 grain bullet 3750+ fps. My load with the 100 grain hits 3760 fps and regularly shoots groups under 2" at a quarter mile. My son shot a 2" 600 yards group last year with it getting ready for his antelope hunt. It is an off the shelf mk 5 wby rifle.

I have shot the 270 and 7mm wby's long range for 35 years. The better bc's in 7mm are why it is a better choice. The 7mm-300 wby was extremely popular as a hunting round and 1000 yard rifle back in the 70's setting 1000 yard world records. It is 200+ fps faster than the standard 7mm wby. Remington coming out with the 8mm rem mag in 1977 making cheap brass available caused the 7mm-300 wby to lose popularity. Necking the 8mm remington gave the same ballistics with cheap brass. After that wildcat became extremely popular for about 20 years Layne Simpson decided to pull his weight with his magazine and make it a standard cartridge giving it the magazine name, shooting times westerner or STW.

I have several of the 257, 264 and 7mm STW's and they are all top shooters and way fun to shoot. The ballistics of the 264 STW are among the best in the business for long range shooting to 1000 yards or so. It can drive the 140 Berger to 3400 fps making it a super long range deer/antelope cartridge. I have one with near 1000 rounds on it and it seems to just get better with age. As newer powders become available the 264 STW just keeps getting better and is one of my all time favorites since before anyone ever heard the wildcat called an stw.

If I had to pick a super long range deer/antelope cartridge it would be the 264 STW because a brake is not needed for pushing the little 140's where it is needed in 7mm pushing high bc bullets. The 6.5 STW with 140 grainers will ballistically outshoot the 7mm STW with 168 grainers.

If I had to pick a long range elk rifle it would be the 338-378 wby. It basically just blows away the competition in a hunting weight rifle and makes hits at long range far easier than with the little stuff off the RUM and Lapua cases. You can use the strong Lapua brass and push it hard to try and get close to the 338-378 wby with an improved Lapua or just shoot faster safely and easily with the 338-378 wby.

So, there are my two rifles for long range hunting weight rifles and I own or have built or shot at my range about everything talked about on this forum with hands on experience.

Tony and I went thru the STW phase about twelve years back (maybe more). He went thru a barrel about every 700 rounds, and shot mostly 140 grain bullets (that area). As far as I know he's still shooting one, as I have not spoken with him since 2006. He tried necking one down to 25 caliber and another at .264. The 25 caliber ate barrels every 500 rounds like clockwork! The .264 wasn't anybetter. Last time I spoke with him he had a reamer ordered to build a .300 Jarrette (same case). He also built a .338/8mm mag rifle, but how well it shot I don't know. It would have been similar to a .340 WBY mag. Told him over and over to forget that STW crap, and simply build a Weatherby mag without the free bore. Cases are already made (he wore one barrel out forming cases and doing load development!)

Just looking at the #7 edition of the Hornaday manual I see that the 7mm STW will push a 140 grain bullet to 3400 fps. But on the otherhand so with the standard 7mm WBY mag will do the samething with a better shoulder and neck design. There's no doubt that with the 162 grain bullets the STW round should be better, but it's not. They come out very close
gary

 

[Trickymissfit]

The 6.5/270 wby mag sounds interesting! I may have to do some research for some data!

very similar to the .264 mag from Winchester, but with a better neck and shoulder
gary

 

[Trickymissfit]

436, I agree that would be a super cartridge without having to alter his rifle. I did one of those for a guy back when I had my shop. The only difference was not that fast a twist. It outshot the 7mm remington magnum ballistically by a good bit. I went back and looked up some old data from working up loads with it and we were pushing 130 grainers into the 3400's and 140 grainers into the 3300's. The weatherby radius is a good design and freebore can work well if the gunsmith works with it regularly and knows what he is doing.

Now do keep this in mind! I ran into a problem with my .270 mag a few years back with the Hornaday SST's exploding on impact, and a few even doing a dissappearing act while in flight. Many modern bullets are not made for those velocities. The SST in .270 was built for 3100 to 3200fps, and I was exceeding that limit a bunch! (130 grain).
gary

 

[Trickymissfit]

Now that remington , nosler and others are making wby brass at the same price as all the others you would think the wby's would start showing up more. They will flat outperform most stuff talked about regularly on this forum. What killed them was the expensive wby brass. That is not an issue any more. I have every wby cartridge except the 224 and 460. Several of some. I do have the 220 wby rocket and the old 375 wby. I have several wildcats based off wby cartridges. They are some of my favorites and some of my best shooters. For some reason the 7mm-300 wby will outperform the 7mm STW by nearly 100 fps. I have no idea why since they are virtually the same with powder capacity. Is it the shoulder design? I have two of one and six of the other and love both cartridges. But the 7mm-300 wby's are faster.

all Weatherby branded brass and loaded rounds are built by Norma, unless something's changed in the last two or three years. There is a difference between the Remington brass and the Norma brass, and the Norma is worth the price.
gary

 

[C.O. Shooter]

Say I go to a 257 wby mag, will barrel length make a difference when it comes to rate of twist or vis versa? Obviously looking for maximum performance!

 

[Long Time Long Ranger]

Norma still makes the wby brass as far as I know. But you can get the brass for wby cartridges cheaper from other makers. Your right, the norma is better.

 

[TOM H]

Hello All,

I am new to the forum, but not to shooting. I have a 270 WBY Mag, Mark V Sporter, sitting in the closet taking up space. I am considering another long range gun and wanted to turn this into a custom. I am looking for something unique, however, easy to convert. I understand for the most part WBY's case are some what similar and would be easy to go up or down in caliber. Not that there is anything wrong with the 270, however, not something I want any more. The rifle means to much to me to get rid of it. I would imagine the .257 would be a nice conversions or go on the high end of a 7mm/300. I currently shoot a .300 Remington Ultra Mag which is very accurate, so I do not know if I want another of that similarity. If I were to go on the larger end of calibers, I am looking at the 338 Laupa! So I don't know, I am just throwing it out there for some other insight!

Thanks for your help!

I think I'm having something build which is alittle unique it a 270Wby on a Rem action. Rock Creek 5r 1/10 twist barrel, No wby freebore and case be headspace on the shoulders instead of the belt. Plan on shooting berger 150gr VLD bullets. Only reason I didn't do a 7mag/7Wby I'm shooting a 280AI and 284. I know the 270Wby won't be what's called real LR rifle be a nice addition to my deer/elk rifles.

 

[bigngreen]

I think I'm having something build which is alittle unique it a 270Wby on a Rem action. Rock Creek 5r 1/10 twist barrel, No wby freebore and case be headspace on the shoulders instead of the belt. Plan on shooting berger 150gr VLD bullets. Only reason I didn't do a 7mag/7Wby I'm shooting a 280AI and 284. I know the 270Wby won't be what's called real LR rifle be a nice addition to my deer/elk rifles.

Take a look at the Matrix Ballistics bullets if you haven't yet, the 165 in a 1-10 twist is far better than the 150 Berger.

 

[FEENIX]

If you load one of the 165+gr 277 bullets in that it will out run the 6.5's and 7mm in just about any form.

+1! The static BCs are very impressive: 165ge VLD = 0.7381 and 175 = 0.7828.

.277 Caliber Rifle Bullets Built for Accuracy | Matrix Ballistics

Good luck!

Ed

 

[Long Time Long Ranger]

I have loads for my 270 wby's with 160 grain noslers at 3200 fps. So with those 165 matrix bullets now at .7381 bc it would be one of the best long range rifles out there. Has anyone verified the bc to be accurate.

I guess I need to order some and bring out the old 270 wby again.

 

[bigngreen]

I have loads for my 270 wby's with 160 grain noslers at 3200 fps. So with those 165 matrix bullets now at .7381 bc it would be one of the best long range rifles out there. Has anyone verified the bc to be accurate.

I guess I need to order some and bring out the old 270 wby again.

The Matrix Ballistics BC is a calculated BC only good for comparison within that product line. I've run the 165's out of my 270 WSM and 270 win and a .650 BC gets me real close at 1435 yrds, when I get my barrel back I'll put it on paper out there and finalize the BC, others have had it in the .660 range. The 175's are running around .700 I guess but I have yet to confirm it myself. They are the most accurate bullet I've ran out of either rifle as well and easy to tune, the WSM runs nice at 3050 fps but can be pushed over 3100 with the 165's