Why did Winchester use .277 for the 270 in 1923?

Dr T

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Many years ago (like in the 1960's) when I was beginning to lust for my first REAL (i.e. not a 22 rimfire) rifle I began to ponder: Why (at that time) were there only two commercial cartridges using a 0.277" bullet: The 270 Winchester and the 270 Weatherby. There were lots of rifles using other bullet diameters in 6.5 mm (0.264") and 7 mm (0.284"), but only those two with 0.277. It seemed to me at the time (and still does) that for all practical purposes that the performance from 0.277" and 0.284" would be identical. Literally volumes have been written on the technical hairsplitting.

Was it something that was driven by a non-technical issue for advertising? Did "270 Winchester" roll so easily off the American tongue that Winchester thought it would sell better? Were the memories of the Great War so fresh that Winchester thought that using the same bullet as the 7 mm Mauser would be considered as some how traitorous and un-American?

Is there some other reason?
 
Funny, Brian Pierce just published an article about the 270 Winchester in the current edition of Handloader, but doesn't attempt to explain the why behind the then-unique bullet diameter choice.

I think it could very well have been a marketing decision -- as the only commercial .277 cartridge at the time of introduction, it set Winchester apart from the competition. I like the .270 a lot, and have just finished assembling a new rifle from components in this chambering. Still, I can't really see any particular ballistic advantage to .277" bullets over .285".

Remington700270.jpg
 
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I think they decided to call it a
.270 Winchester first and then decide .035 inch depth of of groove for rifling was optimal. The actual bore if you could accurately measured across lands is .270 I believe. Hence the Theoretical engraving depth available for bullet diameter. At least my thoughts.
 
I've always wondered where the idea for a .277 bullet came from . I've always thought if Winchester had used a .284 bullet at the same pressure they used for the .270 , it would of outsold everything else since 1925 . Remember , the 270 and 30-06 both came out at the same time in bolt action sporting rifles . A .280 Winchester would of probably prevented the Win and Rem mag's from being launched .
 
7mm converted to inches is 0.276". The Winchester guys might have been confused by the Brits who named their 7mm cartridge 276 Enfield which came out in 1912 or so. The Brits did use a 0.282" bullet but called it the .276 because they use the diameter inside the lands, I believe.
 
7mm converted to inches is 0.276". The Winchester guys might have been confused by the Brits who named their 7mm cartridge 276 Enfield which came out in 1912 or so. The Brits did use a 0.282" bullet but called it the .276 because they use the diameter inside the lands, I believe.

There might be something to that , also the .276 Pederson was projected to become the next service rifle cartridge at the time. maybe they thought they were getting out in front of the curve . I can't imagine that Winchester wouldn't of had actual bullet diameters of both cartridges though . A lot of what we think of as "standard " wasn't so standard at that time , the model 95 was the only civilian rifle available in 30-06 , and it was available in at least 5 .30 caliber options ! 30-40 , 303B ,30-03 , 30-06 and 7.62X54R .
 
There might be something to that , also the .276 Pederson was projected to become the next service rifle cartridge at the time. maybe they thought they were getting out in front of the curve . I can't imagine that Winchester wouldn't of had actual bullet diameters of both cartridges though . A lot of what we think of as "standard " wasn't so standard at that time , the model 95 was the only civilian rifle available in 30-06 , and it was available in at least 5 .30 caliber options ! 30-40 , 303B ,30-03 , 30-06 and 7.62X54R .
The only problem with this theory is that the ".276" Pedersen, was also a .284/.285 diameter bullet.
 
The British are a confusing lot.

The .303 rifle used a .311/.312 bullet, the .455 pistols used .455/.456 bullets, the .380 Rook uses a .375 bullet, the .450 Martini was a .455 bullet, the .577 Snider used a .570 bullet, and .577 Nitro has a .585 bullet.

We Americans aren't much better, the .30-06 and the .308 Winchester both use the same bullets, as do .222 Remington, .223 Remington and .224 Whetherby.
 
Winchester did not invent the .277 bullet diameter for rifles - Mauser produced the 6.8x57mm for China ca. 1907. More recently, the U.S. military has 'rediscovered' the 6.8mm. Not much new under the sun...

PRD1 - mhb - MIke
This is the story I have heard most often as the explanation for the “obscure” .277….the Chinese had it first, and imitation is the sincerest form of flattery.
 
120 years ago every country had its own state owned arsenals, so odd calibers weren’t a problem, it even seemed like an advantage that other countries couldn’t chamber them. Two world wars later , we realized that sharing ammo with allies was kind of a good idea and more advantageous than the enemy not being able to use yours (if they stole your bullets, they probably also stole some guns to use it in too).

Now as to the 277…. I’m curious why they settled on that too. Winchester was big enough to make up whatever cartridge they wanted to. It’s a good middle ground, but so is .284 or .264.
 
No one really knows. Whoever made the decision never documented why they came up with 277 instead of some other number. One article used simple ratios to make the case that .277 was picked just to be between existing bullet diameters. At the time, 0.277 was a unique bullet diameter.

Cartridges are introduced to make profit for the manufacturer. Whether the cartridge actually fills a niche, does something, is secondary to its true profit seeking purpose. Therefore, there does not have to be a legitimate technical reason for the thing. It just has to appeal to the public and sell.

It was "new and improved". And it sold well. Many believe that an animal can tell the difference in being hit by a bullet 0.031 inches smaller than a 308. Must be true, I read it somewhere.
 
Pure speculation, but I wonder if it’s simply to have something “different”. Gun people are goofy as goofy gets. We see it here with guys that go to great lengths and expense to change the shoulder angle 1/2 a degree or bore diameter the thickness of a sheet of paper. Ready to get into a fist fight to defend their baby
 
Cartridges are introduced to make profit for the manufacturer. Whether the cartridge actually fills a niche, does something, is secondary to its true profit seeking purpose. Therefore, there does not have to be a legitimate technical reason for the thing. It just has to appeal to the public and sell.

The 270 was a commercial failure for the 1st 20-25 years after introduction. Winchester almost dropped the cartridge from production until some guy named Jack O'Connor fell in love with it and started writing about it. That is when sales picked up.

Just a theory of mine, but I think Winchester was trying to improve on the 7X57 but didn't want to confuse buyers by giving it a 7mm name. Remington made that mistake when they took the 7mm-06 Wildcat and couldn't decide what to call it. There are rifles out there stamped 7mm-06, 280 then 7mm Express, then back to 280 that all shoot the same cartridge.
 
No one really knows. Whoever made the decision never documented why they came up with 277 instead of some other number. One article used simple ratios to make the case that .277 was picked just to be between existing bullet diameters. At the time, 0.277 was a unique bullet diameter.

Cartridges are introduced to make profit for the manufacturer. Whether the cartridge actually fills a niche, does something, is secondary to its true profit seeking purpose. Therefore, there does not have to be a legitimate technical reason for the thing. It just has to appeal to the public and sell.

It was "new and improved". And it sold well. Many believe that an animal can tell the difference in being hit by a bullet 0.031 inches smaller than a 308. Must be true, I read it somewhere.
Absolutely agree. There hasn't been a need for some new performance level since 1950 or before.

I also feel that in a national defense situation, the fewer chamberings there are, the easier it is to supply them. If our civilians ever have to defend the soil, sharing ammo with neighbors will depend on what interested them in peace time. I doubt that my neighbors have 7x57 to share with me and I don't have .223s or any form of Crudmore. Doesn't matter though. I don't think I would last long in that scenario anyway. 8-(
 
I think Gordon is on the right track. Even today if you take a 7mm barrel blank that has just been drilled and reamed and before the rifling has been cut the inside diameter of the hole is .277. Winchester knew that back in 1923. All they had to do to make the change was to drill and ream a barrel blank to a .270 diameter and cut the rifling groves at a depth of .0035. Thus they named it the 270 Winchester which is the diameter inside the lands. To get to the new bullet diameter Winchester just reduced the size of the bullet by the depth of the 7 mm groves.
 
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.270 bore:

17/64 gun drill, then ream 0.004" over (0.004" to .005" is a good clean up, 11/32" + .004" = .347" [bore diam .357], 19/64 + .004 = .300", 7/16 + .0045 = .442 [bore diameter for .45 cal])

Rifle grooves to 0.0035" depth.

.280 bore:

7mm gun drill, then ream 0.002" over, if you use a 17/64 you need to ream 0.011".

Rifle grooves to 0.004" depth.
 
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Gun/ammo manufacturers have always seemed to me to be a little odd. Like some others here, I think the .277 bullet size/.270 cartridge name was chosen to be a “new and improved” thing to push out to the masses. (Like the .250-3000 Savage created and marketed.)

I love the story, whether it’s true or not I don’t know, behind Marlin only using the caliber designators .25-20/.32-20/.38-40/.44-40 because they didn’t want .35/.32/.38/.44 WCF (Winchester Center Fire) stamped on their guns, and other companies renaming cartridges (or even creating similar rounds) for the same reason. Those old reprinted Sears catalogs had pages and pages of cartridges for sale, some appeared to be duplicates in dimensions and performance by rounds sold by various makers using different names. 🤪

I love my .270, I think its a great cartridge. :thumbup:

Stay safe.
 
The Brits being Brits, many taking the often prescribed cure all, mercurial opium tabs which were opium mixed with mercury tended to see and do things different for some reason.

In the world of caliber designation it was common to use the diameter to the lans as bore diameter not the groves.

However in some circumstances even that wasn’t used. The .404 Jeffries is a perfect example. The .404 designation had very little to do with bore diameter. It was an advertisement for a repeating bolt action rifle of “.40” caliber that held 4 rounds.

The bore diameter on the original .404 was .418, .419 or .423 depending on the maker. Which BTW is why some old classic .404’s are so cheap. Buyer beware all modern .404 ammo and components are standardized at .423.

Anybody ever run across a .256 Newton or a .256 Mannlicher? Both of which are .264 diameter at the groves.
 
The .270 Winchester is not my favorite cartridge in the world but I do like it and have not been without one since before I was old enough to drive. What I think is fascinating is how odd the .277" bore is and how few cartridges use it. For decades there was only the Winchester and Weatherby cartridges. Few have even heard of the REN and then we got the 6.8SPC. With only two major cartridges supporting it, one wildcat and one commercial flop, it has never been difficult to feed one. Meanwhile there are dozens of 6mm's, 6.5's, 7mm's and .30's. Now the military has adopted a brand new cartridge and it's a .277, that essentially duplicates the old .270 out of a 16" barrel and even uses bullet weights in the .270's range.

Truth be told, I bought the Ruger for the wood. :p

1718543671594.jpeg
 
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