Question about the 270 Win

[SUPRX22]

I am curious about the development of the 270 caliber.I'm not doubting the capability of the caliber or the cartridges built around it.They have certainly proved their worth many times.
My question is how did anyone settle on .277 as a caliber or.308 for that matter?I can see the 24s,26s,28s etc with the metric measurements.Even the .257(near 1/4") and .375 at 3/8th make sense.Is there a fractional equivilent to the lands or grooves?
I guess it really doesn't matter but I just wonder.

 

[mcb]

Not sure where it came from but 270 Win is 7mm major diameter grooves are 7.035mm/.277 inch. 7mm Rem Mag, RUM, -08 etc is 7mm minor diameter 7.035mm/.277 land diameter.

 

[Captcurt]

One that always threw me was the 333 OKH that Uncle Elmer used. It was a 30-06 case necked up to 33 caliber and used the .333 Nitro bullets that the British had. Now we have a close relative in the 338-06. I want one!

 

[Slamfire]

I am curious about the development of the 270 caliber.I'm not doubting the capability of the caliber or the cartridges built around it.They have certainly proved their worth many times.
My question is how did anyone settle on .277 as a caliber or.308 for that matter?I can see the 24s,26s,28s etc with the metric measurements.Even the .257(near 1/4") and .375 at 3/8th make sense.Is there a fractional equivilent to the lands or grooves?
I guess it really doesn't matter but I just wonder.

If you were to develop a cartridge you would examine ballistic tables, having decided on an "effective range". You would also have to decide on lethality, just exactly what bullet size gives you the minimum lethality. (You are not looking for the maximum lethality, because no one can carry a 16 inch cannon!) Lethality is very contentious, at least with ballistic tables you can show bullet drop for distance and velocity, but what bullet weight and diameter gives you the minimum lethality, that would be very tough to determine or even agree on. You would also look at cartridge weight, how many cartridges constitutes a combat load. Civil War Soldiers carried 25 rounds in their cartridge box, and there are numerous examples where they ran out of ammunition. Is 200 rounds a combat load? Ever carried 200 rounds of 30-06 in bandoliers? Our oldest WW2 veteran, he said in combat there would be cries from guys wanting ammunition, and to supply their buds, they would fling bandoliers over foxholes and craters. You better be wearing your helmet when a bandolier comes down on your head. A Vietnam Vet buddy, he said he would not deploy with less than 400 rounds and he had fired 400 rounds in several bad days in the bush.

Other factors would be armor/dirt/wood penetration, amount of tracer compound in the bullet, etc. Recoil is important. Someone has to decide what factors are the most important and how to weigh them.

Anyway, that's what I would do, assuming tooling was not an issue. Tooling could be an issue. I read a short summary by Ludwig Olsen why the Swedes adopted the 6.5 mm. It was a tie between the 6mm and the 6.5 mm and it was easier to get a cleaning rod down a 6.5 barrel.

Now what commercial firms do, who knows. It is doubtful Winchester conducted any meaningful analysis or tests, more like back of the envelope ideas. It is possible that the 277 round was based on it being about 95% of the diameter of the 30-06. Maybe it was based on a velocity number that would sell. Faster is better, from a sales viewpoint. Commercial firms exist only to maximize profit, and that requires convincing the consumer that this new round is "better", or "more desirable" than what is out there. Marketing is based on emotions and feelings, so there may have been no valid technical reasons for the 270 Win at all, it is possible the only reason for its existence may be that someone thought it would sell well, and that it was different from another round.

 

[old heeler]

I am curious about the development of the 270 caliber.I'm not doubting the capability of the caliber or the cartridges built around it.They have certainly proved their worth many times.
My question is how did anyone settle on .277 as a caliber or.308 for that matter?I can see the 24s,26s,28s etc with the metric measurements.Even the .257(near 1/4") and .375 at 3/8th make sense.Is there a fractional equivilent to the lands or grooves?
I guess it really doesn't matter but I just wonder.

I've read few articles over the years about 270 and this is just one.

https://www.ballisticstudies.com/Knowledgebase/.270+Winchester.html

 

[Laphroaig]

Actually, the .270 Win wasn't the first .277 cartridge. The Chinese had started to develop a 6.8x57 military cartridge in conjunction with Mauser in the early part of the 1900's. Some rifles were made in that caliber, but shortly thereafter the project was abandoned.

Did Winchester engineers catch wind of those efforts and copy the bullet diameter? Or was it just a coincidence? We'll probably never know

 

[Laphroaig]

There was another thread on this same subject a couple of years ago:

https://www.thehighroad.org/index.php?threads/270-caliber-why.794258/page-3

The following is a post from exactly two years ago, today:

There was actually development of a 6.8 mm cartridge by the Chinese in the early 1900’s. There were two variants, 6.8x57 and 6.8x60, developed by Mauser in Germany. The Chinese had a contract with Haenel of Suhl Germany who produced a 6.8x57 1907 Model rifle based on the Gewehr 88. A number of these rifles were built and shipped to China, but production stopped in 1914 due to WWI. Shortly thereafter, China abandoned the 6.8 in favor of the 7.92x57.

In the US, there was testing of a “28” caliber cartridge based on the 30-06 case in the period 1910 to 1913. Not much is known of the specifics of this testing. Winchester might have participated.

Then, in the period from 1918 to 1921, Chinese General Liu, commander of the Hanyang Arsenal, came to Springfield armory on at least 2 occasions to participate in tests of a self loading rifle developed in China utilizing the 6.8x57 round.

I checked several sources but much of the above narrative came from this thread on another forum:

http://www.iaaforum.org/forum3/viewtopic.php?f=1&t=4427&start=0

Just looking at the above sequence of events, it seems likely that Winchester might have gotten the .270 idea from the Chinese when they were here at Springfield.

But wait! Check the post by Historian (everybody’s named Historian on that site) on the second page, dated Thursday July 3, 2008 at 2:08PM. He claims that there is a drawing from Winchester Dated January 16, 1917 showing their .270 Cartridge prototype. If this is true, then maybe Winchester came up with the idea independently? Historian gives some references at the end of his post that I might try and check out next time I’m at the big library in Pittsburgh.

I think that world events during and immediately after WWI would make collaboration with Germany unlikely. Unless maybe General Liu corresponded with someone over here during that time period? Liu was apparently educated in America. We’ll never know but I think Winchester knew of the Chinese round somehow.

Finally, one thing is apparent to me. If the Chinese were involved, it lends credence to rc’s post that Harbor Freight was somehow in the picture. Is rc ever wrong?

Merry Christmas everyone!

Laphroaig

 

[Mn Fats]

Is rc ever wrong?

I think I caught him wrong one time years ago when I was under a different user name. Other than that, never! I sure miss that guy.

 

[Clark]

I have lots of centerfire rifles, but only some are getting big game
I have killed 0 with .198" bullets
I have killed 0 with .224" bullets
I have killed 2 with .243" bullets
I have killed 5 with .257" bullets
I have killed 2 with .264" bullets
I have killed 9 with .277" bullets
I have killed 14 with .284" bullets
I have killed 1 with .308 bullets.
I have killed 0 with .323" bullets
I have killed 0 with .338" bullets
I have killed 0 with .357" bullets
I have killed 0 with .400" bullets
I have killed 0 with .452" bullets
I have killed 0 with .458" bullets
I have killed 0 with .500" bullets.

 

[Picher]

I've read few articles over the years about 270 and this is just one.

https://www.ballisticstudies.com/Knowledgebase/.270+Winchester.html

Very good discussion on the .270 and various factory loads. I used Accubond loads to kill my moose and at 270 yards, the 860 lb. (dressed) bull only went about 15 yards. Interior damage was really impressive.

 

[WestKentucky]

Don’t know how they settled on that diameter, but it sure does work well. Seems an odd place to stop in between 6.5mm and 7mm which both are old school military bores. Maybe they went after a 6.75 mm and rounded up to 6.8. Either way I like it, in my .270 and in my 6.8spc. I want an odd .277 round for my contender too but can’t force myself to spend the money on barrel, brass, dies, etc, not to mention the jewelry it would take to calm the wife down.

Toss chocolate and diamonds like grenades fellas, that’s makes them happy, for a little while.

 

[jmr40]

I've seen several of these debates and never heard a definitive answer as to why Winchester chose .277 over other calibers. The best guess is that they wanted something just a little different than 30-06 and 7X57. In 1925 by the way 270 and 30-06 were two completely different animals. The most common 270 load was a 130 gr bullet @ 3000+ fps. Most 30-06 loads were 180-220 gr bullets and they were loaded much closer to modern 308 levels.

Today, with modern bullets and loads the 2 are ballistic twins. The 30-06 is loaded 200-400 fps faster than in the 1920's and with 150's will match 270 trajectory with 130's. The 270 with modern 150 gr bullets will take down bigger game just as effectively as 180's from a 30-06.

But the 270 was not an immediate success. The round and rifles for it had been on the market for 25 years and sales were so slow that Winchester was ready to drop it. Then Jack O'Connor started writing about it and it soon became one of the all time best sellers.

The 270 BTW is based on the 30-03 cartridge, not the 30-06. Of course the 30-06 is a modified 30-03 so they are similar. But for unknown reasons Winchester chose to base the 270 on the 30-03 case instead of 30-06.

I can see the 24s,26s,28s etc with the metric measurements.

The European 6.5X55, 7X57, and 8X57 were all developed before the 30-06. In fact the1st two before the 30-30. It would have made a lot of sense to just use those rounds for both hunting and military use, but I suspect nationalism was the primary reason for developing something different. No one thought a caliber in a metric designation would sell well in this country, and for the most part they are still harder to sell. In England the 7X57 is/was called a .275 Rigby.

 

[Larry Ashcraft]

but I suspect nationalism was the primary reason for developing something different.

Agree. I read, somewhere, many years ago, that Winchester didn't want a 7mm round, because it wouldn't sell. American shooters didn't want a "mm" round, so they chose the .277 cal bullet and called it a .270. I also remember reading about the Chinese connection.