A faster .270 (.277)

that would be pretty awesome....

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But not for long...an Ultra Mag in 270 would give the word "overbore" new meaning....barrel might last 500 rounds, maybe.

That's at least 500 rounds of "awsomeness"!

That would be 500rds of bench rifle. You'd need a 30" barrel to really see any benefit worth writing home about. If I'm toting something that silly around I'd just as soon it be in a larger caliber.

Even the 7 RUM is on the wrong side of efficiency and needs a barrel considerably longer than most anyone uses to get any real benefit.

One guy here, if you search, IN A CUSTOM ACTION
turned his 270 in a ray gun, I think he got some up to 48-5K range

why, well, cause he could, he was concerned about the bullets, I guess once you start pushing that fast, you need to switch to something like the copper/bronze monolithic (ie. solid, not jacketed) bullets, as they just don't hold up EDIT: in the barrel.

I dunno to me who actually uses and reloads for the .270 WSM it seems to have potential right to the sensible limit of caliber. I see 200+ fps over (both 24" barrels) the hyper efficient .270 Winchester I been loading for for 30 years and I am not even getting near max load areas. At 3375FPS for the 130 grain load I worry about close in bullet performance with anything xcept bonded premium or monolithic bullets. I load 140 grain bullets at 3200 fps with no fuss and fabulous accuracy. What more can one ask with matter projectors as we currently think about them!

I don`t know, but the 7x75 R Super Express Vom Hofe is pretty bad azz....................

I like 270 wsm

270 WSM 130gr bullets at 3,400fps (handloads), Shoots flatter then a 257 Wby, the day I need something faster then that I will build a rail gun

I was only guessing 3250 for my 130 gr load, 3400 is outstanding.

I've got some 100gn Accubonds meant for the 6.8SPC that might find their way into a .270 WSM load just to see what they'll do. The only thing that might be faster than that would be the 85gn TSX.

I had the idea of necking down a 7 rem. mag. or 375 h&h to .277(270).

I had the idea of necking down a 7 rem. mag. or 375 h&h to .277(270).

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Basically a .270wby then..... The only difference is the longer neck on the Wby....and of course the double radiused shoulder. I make .270 wby from 7mm Mag

There is only.007" difference in dia between 7mm and 270. To me given all the other problems of the world .007" is small enough difference that if there was a superfast 7 I liked I would just shoot the 7. Not demean anyone just sayin.

Even the 7 RUM is on the wrong side of efficiency and needs a barrel considerably longer than most anyone uses to get any real benefit.

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This.

In a typical 24"-26" sporter tube, the 7 RUM has no velocity increase over the smaller 7 STW, despite burning an extra 15 grains of powder. Further shrinking the bore size just exascerbates the condition. It's been done, all the way down to .257" on the RUM case (.25-300 RUM).

I like the .338 McMurdo for absurdly overbore myself. Essentially a cut and necked down 50BMG case with a .338 bullet at the front. Incredibly fast (from a 36" barrel) and barrel life around 250rds.

And then there's the .50 FatMac...

What would you want it to do that a .270 Win won't do? Do you just want a bigger-louder-boomer? If so, just move up to a .340 Weatherby Mag.

More velocity means more range...

sure, but in a lighter bullet it's limited
you still look at drag loss, and the faster you push it, the more diminishing the returns.

More velocity means more range...

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Only when compared to slower catridges of the same caliber.

There are no super-high BC .277" bullets.

If you want the most potent, longest range cartridge under .30 cal, it's the 7mm STW. If you really want .277" bore, I'd suggest using the same case (which is the 8mm Rem Mag case). Burning more than 80-85 grains in sub-.30 cal bores and barrels of practical length only serves to waste powder and accelerate throat erosion.

I'm a big fan of fast rounds. I have a .17 Rem, a .220 Swift, 6mm Rem, .25-06, 8mm Rem Mag, .375 RUM, and I'm about to build a 6mm-06 AI. However, I also understand that there's a point of diminishing (or no) returns when you start putting a humongous charge behind a relatively small bullet. I'm just trying to help you with what I've learned.

For factory rounds, the .270 WSM is king of the hill in .277" bore.

In the hands of 90% of the shooters or hunters, the .270 Win is more than they will ever need or use.

The high BC bullets are coming from Nosler. I have a 270 WSM and 7 WSM. Great cartridges.

Yes with low BC bullets the increase in effective range is marginal for an increase in velocity, but it is there. If it weren't the .220 Swift and .22-250 wouldn't have any appeal over the .223 Rem and the .300 Win Mag would have zero to offer over the .30-06.