270-300 Win Mag now feasible

[yorke-1]

I am glad I was steered to this thread. I read most of the first 3 pages and several posts between page 4 and 40. I have learned that my idea was not so revolutionary. I like the 270 caliber. do not get me started on 6.5MM and 7MM bores. I will make his short, I do not like them. I like the 0.257" and 0.277" bores with heavy twist rates. I like the thought of a 270-264 Win Mag. Just a 0.013" expansion to the neck and it would be great for me. I would love to work with that parent case. I would use the cheaper of the two cases I am looking at. the 7MM Rem Mag is the same case; I have a huge pile of that useless cartridge case that I was going to turn into a bunch of 264 Win Mag when I was going to make a long range 264 Win Mag.. now I want a long range 270 made with the 7MM Rem/264 Win Mag Case. there seems to be some controversy as to which came first. Ironically the 7MM fans are dead wrong. the 264 win (1958) is the parent case for the 7MM Rem (1962). Now that I know that there is a 270-300 win mag: I think I will pioneer the 270-264 win mag or 270-7MM rem mag. I think a 1:8" twist, 26" #5 taper (.750" muzzle), on a model 70 or Sako A7 with a Chet Brown "pounder" sporter stock would be the perfect rig for me when I get to my new place up north. I reckon I am going to hear from the 7MM guys and the 6.5MM guys..

That's a good idea, but I think Weatherby beat you to it by a couple years. LOL

A 270-264 Win Mag would end up right around 81-82gr H20 capacity which is right there with 270 Weatherby. If you set it up right though you could just fire form 270 Weatherby ammo in it I guess.

 

[Big Jake Duke]

"... I reckon I am going to hear from the 7MM guys and the 6.5MM guys..[/QUOTE]

You know- a 6.8 Creedmore........

Just kidding.

But it is true that a 270 Weatherby is really a 270-264 0r a 270-7mm, just with more expensive brass! You could go 270 STW, or call it the 270-375 HH Magnum Express.

Good luck and go have some fun.

 

[freddiej]

Big Jake Duke,
I have had a dream of having another 270 like the that one I had up north. it was stolen ater a prong horn hunt in eastern Montana. I loved my 270-264 Win Mag. Feenix told me about your cool 270-300 Win Mag and I thought I would say howdy to a fellow 270 fan. I loved my 270-264 W/M when I owned it. I never needed to make it full tilt boogie to reach out to 600-700 yards with the Berger 160's or the Barnes 150's. I took Elk, Deer, Pronghorn, a few coyotes, and a singular ground squirrel (pink mist). I had a 1:8" twist barrel to stabilize the long slugs. McGowen barrels barreled the Win M-70 with one of their great 26", #6 profile, 8 flute barrels with a muzzle brake. My employer supplied a nearly unlimited 7MM Rem Mag cases for forming the 270-264 W/M case. This gun was my first "custom" gun. it was lack of a better description my "go to" gun for pretty much anything with the right slug it would make short work of anything I was hunting. If your 270-300 W/M is anything like my rifle it should be a real flat shooter and every bit the Elk hammer with heavy slugs and deer with anything light. hats off to you. I hope this gun serves you like mine served me and will again once mine it's built/back from Kalespell, MT..

 

[freddiej]

That's a good idea, but I think Weatherby beat you to it by a couple years. LOL

A 270-264 Win Mag would end up right around 81-82gr H20 capacity which is right there with 270 Weatherby. If you set it up right though you could just fire form 270 Weatherby ammo in it I guess.

I do not care much for the 270 Weatherby, I have owned one int he past.. too much free bore to keep the pressures down. I have owned and shot the 270-264 W/M also known by the 270-338 W/M. I know the 270-264 WinMag works and the 270 weatherby not so much. It all comes down to what you know and trust. my hats off to Roy W. he made some real barn burners and his 460 is nothing I would personally fire ever unless my life depended on it. I do like the 257 Weatherby. that one seemed to work much better than any other of Roy's magnums.

 

[Renegade70]

I have been wanting to build a 270-300 for a while. I have a solid old Winchester 770 with a used up 300 WinMag barrel as a good candidate. It shot really well for a long time until it was loaned out to the wrong person.

Unfortunately, it looks as though Pac-Nor may not chamber the 270-300 again. My guess is that the reamers were lost in the fire, and with new 0.277" chamberings, they don't feel the demand is there. It is however my preference, as I have multiple rifles in 300 WinMag and 270 Winchester.

Has anyone gone elsewhere for the 270-300? I'd like to have a match grade or better barrel, 26", nitrided.

 

[sloone]

i will tell you this much.i had a 270-300 win mag built in 2005.i shot barnes 130 mrx which are no longer made and 140 accubonds.the most accurate hunting rifle i ever owned.possibly because my smith also made my dies.with those 130 mrx the rifle was capable of groups in the low zeros to mid zeros.the 140 accubonds would shoot .2 or less.had a broughton 1-10 twist.i believe it was just a hummer barrel.kevin weaver in colorado built it and i believe still has the remer for it.tell him mr bob sent you his way.

 

[The Hock]

I was talking to Kevin last week. Broughton might be outta buisness. He said the last one was a 3 year delivery.

I've got one in 270 WSM that hammers but go to cut rifled barrels these days.

 

[sloone]

hi hock.yes tim shut down couple years ago.used many others before that 1st broughton.then 3 more on other builds after that.as far as accuracy i belive if both quality you cant shoot the difference.many great barrel makers today.my next build in 6.5-300 wby will run a benchmark.cut rifled.they are excellent.

 

[sloone]

if your shooting 130 or 140's try 72.6 grs of reloader 22,thannk me later.good hunting to all.

 

[Brad Norman]

I know that the 277 caliber bullets have been victims of their own success. There are millions of 1-10 twist barrels so bullet manufacturers have been slow to add high bc bullets for long range that would require a faster twist, believing that the market share is too small to be a vaild market. But this year- should be this summer, Berger is entering the field with a 170 gr .704 tested bc. We also have the newer Nosler LRAB 150 gr with a .625 bc.

I heard Bob Beck on Firing Line Radio Show talking about the Berger Bullets he was testing in a 270wsm. And i got the bug.

I just rebarrelled my favorite 300 win mag with a 28" #6 1-8 twist barrel in 270-300 Win Mag from Pac Nor.

I believe i will have a velocity on the 170s of close to 3300fps, the 150s a little over 3400fps. Only step is annealing and necking down a 300 win mag to .277.

Let me know what you think. I have nitrided the barrel, so im not worried about a short life .

I agree. Manufacturers have been slow to modernize the .270 Winchester and other .270 cartridges. I'm sure they thought "Why mess with something that works so incredibly well already?" Now many shooters and hunters are showing interest in reaching "out there" farther than they'd considered previously. Long range and ELR sports seem to be booming (pun intended) and I think the cartridge you've developed will work very well for you. There is something unusual and special about a properly-placed .277 diameter bullet when it comes to making quick clean kills on game.

Not too long ago I was studying the concept of the 6.8 Western. I decided to stick with the .270 Winchester cartridge I've had such great results with for decades. Since I had my Grandfather's old Remington lying around with a worn barrel, I just replaced it with an 8-twist and long-throated it. Now I can shoot the Sierra 175 TGK with full neck support on the bullet while seating it out far enough to maximize powder space. The rifle turned out to be wonderfully accurate. My rifle with the new barrel also shoots just fine with the old standard 130, 140 and 150-grain bullets designed for the ubiquitous 10-twist barrels everyone produced since 1925.

My old .270 Winchester can't compare with the velocities you'll get with your magnum case. So, I'll just dial on a little bit more vertical and not worry too much about the wind as the new heavy-for-caliber .270 bullets have really good BC numbers. I have LOTS of .270 brass so sticking with the grand old Winchester cartridge was an easy decision for me.

Best of luck to you Sir and happy hunting!!

SF -
Norman
Nevada

 

[Brad Norman]

Thr barrel is back, i met with Jim Gruning today to screw on the barrel, set headspace and cerakote it. Now i am going to work on loads.

I have Matrix 165s and nosler 150 lrabs.

I am planning on trying imr7828 and h1000.

I have had great luck with imr4350 in 300 mag but i think it will be a little too fast for this cartridge.

Thoughts?

Even in a standard .270 Winchester case, with the heavy 175 Sierra bullets, 4350 is too fast. H4831 was only a little better. If you want to stick with temperature insensitive powders there are some slow ones from Vihtavuori. I think H1000 and Retumbo will likely work well for you. They are slowly becoming available again. Good luck Sir!!