Bullet diameters

[elkeater2]

One of the things that amuses me are the actual diameter differences between calibers, especially the ones people tend to argue about. Example - the .257's some of us like vs. the .264/6.5mm : .007"; .243/6mm vs. 257 is .014";. 6.5mm/.264 vs. .270/.277" is .013". So the jump between calibers varies from about 5% to 18% in terms of frontal area. What we really need is something like a 29 Nosler :roll: to fill that big gap between 7mm/.284 and the .30cal/.308's : .024". That doesn't look like much, but it's a 17.6% increase in cross-section or frontal area. The difference between the .257's and 6.5/.264's is 5.5% - one of the smallest.

What really makes the difference today when choosing cartridges and bullet diameters is bullet selection options and the shooter's own list of things he wants to do with the rifle.
EE2

 

[salmonchaser]

Now you're on to something.

 

[JD338]

Good point. Not much difference between the 270 and the 280 if loaded to the same pressures.
You have a much broader selection of bullets weights and styles of you pick .284" over .277".

JD338

 

[Grundy53]

It really puts in to perspective the actual difference between an"undersized" bullet and a "over kill" bullet. Haha

sent from my typewriter

 

[Vince]

Thank you for the realistic perspective.
Now I need to go find a 105mm projectile and end the debate once and for all.

 

[Songdog]

Someone beat you to the .29 cal....

John Barnsness designed the B-29 cartridge about 10-15 years ago.... it was featured in a Handloader magazine cover article.... pretty amazing if I remember correctly.

 

[sask boy]

As we all know it is mostly what ever tickles our fancy 8) there has likely been more game shot with a 30-30 Winschester then any other calibre and you can almost watch the bullet leave the barrel.
There are just so many calibres and to little time .

Blessings,
Dan

 

[Anonymous]

As much as we hate to admit it… there is very little practical difference in field performance on game with modern bullets from .25 to .32 at common ranges provided the shooter knows what he's about. I do think the .338 and up have a noticeable effect on big game over smaller rounds but double lunged is double lunged.

The whole .270/.280/.30'06 discussion is akin to theologians debating the number of angels dancing on the head of a pin.

 

[DrMike]

The whole .270/.280/.30'06 discussion is akin to theologians debating the number of angels dancing on the head of a pin.

Ha! Everyone knows it depends on the size of the pinhead. And there are always a lot of pinheads around. :grin:

 

[Oldtrader3]

Academically speaking of course, there are always a lot of "pinhead's" around to dance on. That we can all agree upon! This is as someone mentioned about arguing between a .257 and a .264 bullet at long range?

As elkeater refered to: when you think about it, dynamically, there is only .0035 curvature difference per side. Think about this with critical thinking skills and tell me that the bullet company's can not make an optimal grain weight bullet in both calibers with nearly identical Ballistic Coefficients for each of these two calibers which so closely resemble each other?

What (again) were we so sure about in the arguments regarding this topic earlier? Think about it again and tell me that one is superior to the other?

 

[Guy Miner]

Regarding deer, I've seen absolutely NO difference in killing power, from up close to 300+ yards (maybe 400) from the 6mm/.243 size cartridges and the .300 magnums. Or anything in between.

You have? Really?

How does one beat "instant" ?

I can understand on bigger and/or tougher game, that the bigger bores & heavier bullets do a better job. Truth is though that most of us hunt deer, not something bigger.

Regards, Guy

 

[Oldtrader3]

Math games can be fun but drawing dividing lines of numbers like shape factors (ballistic coefficients) gives one a false picture of what exterior ballistics is really about. The contrast of the .25 caliber against the 6.5mm caliber with a .007 difference in diameter shows that figures don't lie but they are misleading because it would be so simple for bullet companies to make a high ballistic coefficient .257 caliber which would mirror the 6.5 mm. Remember the 6mm Lee Navy! These cartridges are only .007 diameter difference, but marketing economies hold these changes back from happening and hold the old decisions about 19th century ballistics in sway, despite good reasons not to continue the mistakes of the past.

For some reason long forgotten, back in the dark ages of 19th century ballistic designs mostly for the various permutations of Mauser rifles, ballistic decisions were made around the design of the Mauser and Mannlicher military calibers which still affect ballistics today. These decisions back then were based on trying to match ballistics of small, short cased military rounds (6mm, 6.5mm and 7mm) which proscribed long, small diameter bullets for these calibers versus the larger diameter, shorter bullets of the .30, 8mm and 9mm calibers in order to control recoil and match ballistic performance on the killing fields of European, post Crimean War, military strategy.

This reasoning still permeates modern ballistics and has lead to the caliber confusion and configurations that we still use today. Hopefully somebody will wake up some day and modernize cartridge design to at least be free of archaic and shortsighted 19th Century military thinking!

 

[IdahoCTD]

Matrix bullets made some .29x bullets for a gun shop is Wyoming not too long ago. It's hard to imagine that we need more calibers.

 

[Oldtrader3]

No, we have plenty of calibers but are stuck in 19th century thinking still in bullet and cartridge design.

 

[SJB358]

Heck, I just want them all. They all have something cool and fun to offer! HA!