autogun

Military Guns and Ammunition

Hosted by autogun

This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons.

  • 3232
    MEMBERS
  • 183536
    MESSAGES
  • 36
    POSTS TODAY

Discussions

True Velocity polymer case ammo   Ammunition <20mm

Started 17/11/17 by gatnerd; 11546 views.
EmericD

From: EmericD

19/9/20

Only a few years prior to .30-06 (which really had its COAL set by .30-03, not by any aerodynamic principles) the French with their heights of understanding thought that the lowest drag ogive possible was a 2 caliber long tangent, based on atomic newtonian principles. 

Depends on what you call "a few years prior".

In France, nearly all the work on modern bullets was done between 1893 & 1896, and i7 bullet form factor as low as 0.82 were achieved at this time (and they had access to better instruments than only ballistic pendulum, electricity was known at this time).

So, 7 years before the adoption of the .30-03 everything was known (but kept secret), so ok let's say that the .30-03 and the .30-06 were just a bad timing...

The USA produced the Mle1898D bullet during WWII, and were perfectly aware of its ballistic advantage. By 1917, they did know that the shape of the Mle1906 bullet was not as good as it was supposed to be, so they copied the Swiss GP11 to make the .30 M1. During the '20s, when the "impoverished" US ordnance developped the .276 Pedersen, the bullet shape was following the best recipe known at this time.

They reverted to the Mle1906 shape for the .30 M2 excatly because the M1 had too much range, and not enough drag...

During the development of the M59 bullet, the US did known that better shapes were available because they used a secant ogive instead of a tangent ogive, but it was a very short one and didn't even cared to use all the space available. They selected a 1.8 calibre secant ogive when they have space for a 2.5 calibres ogive.

During the production of the .223 Remington, they did know that the 5.5 radius ogive used by Remington to load the cartridge was very inferior to the Sierra bullet used during development.

So, did they know that better shapes were available, I think the answer is "yes".

Did they cared? Not really.

QuintusO

From: QuintusO

19/9/20

EmericD said:

Depends on what you call "a few years prior". In France, nearly all the work on modern bullets was done between 1893 & 1896, and i7 bullet form factor as low as 0.82 were achieved at this time (and they had access to better instruments than only ballistic pendulum, electricity was known at this time). So, 7 years before the adoption of the .30-03 everything was known (but kept secret), so ok let's say that the .30-03 and the .30-06 were just a bad timing...

Correct, but these would have been secret for quite some time, correct? The US had no such ballistic program during this period.

 

EmericD said:

The USA produced the Mle1898D bullet during WWII, and were perfectly aware of its ballistic advantage. By 1917, they did know that the shape of the Mle1906 bullet was not as good as it was supposed to be, so they copied the Swiss GP11 to make the .30 M1. During the '20s, when the "impoverished" US ordnance developped the .276 Pedersen, the bullet shape was following the best recipe known at this time.

Correct, and it really confuses the heck out of me why the projectile shape for .276 Pedersen wasn't inherited by the .30 T65 program. I honestly have no answer to this, they simply went back to the M1906 shape in 1944 for seemingly no reason and then they kind of half-assed a secant ogive in there last minute.

EmericD said:

During the production of the .223 Remington, they did know that the 5.5 radius ogive used by Remington to load the cartridge was very inferior to the Sierra bullet used during development.

The .222 Remington Special was really a crash program. The people designing it (Stoner, etc) had never designed a small arms round before and were using what they knew. Should more effort have been put in? Sure. In fact, I demonstrated casually that they could have had an 0.73 i7 ogive at the time using only features present in extant bullets in the early 1950s.

EmericD said:

So, did they know that better shapes were available, I think the answer is "yes". Did they cared? Not really.

When I said they didn't know, I meant specifically during the development of the .30 M1906. Anytime after 1925? Yes, they knew, and it's extremely frustrating that they didn't seem to care.

Farmplinker

From: Farmplinker

19/9/20

I would blame the NRA. As long as the bullet was good enough for target shooting, why bother with further development? Especially if it results in higher ammo costs.

EmericD

From: EmericD

19/9/20

QuintusO said:

When I said they didn't know, I meant specifically during the development of the .30 M1906. Anytime after 1925? Yes, they knew, and it's extremely frustrating that they didn't seem to care.

You're right for the Mle1906, and I extended the discussion too fast.

I agree that reducing the ogive height from 25 mm down to 23 mm in 1906, while a move in the wrong direction, can't be regarded as a bad decision at this time.

Further reducing the ogive height from 23 mm to 20 mm for the T65 cartridge, while at the same time focusing on bullet penetration up to 1800 m, was really a bad move.

QuintusO

From: QuintusO

19/9/20

I don't think they had anything to do with it.

QuintusO

From: QuintusO

19/9/20

EmericD said:

You're right for the Mle1906, and I extended the discussion too fast.

No worries.

EmericD said:

I agree that reducing the ogive height from 25 mm down to 23 mm in 1906, while a move in the wrong direction, can't be regarded as a bad decision at this time.

Not sure I understand. Ogive space got longer with .30-06, not shorter.



 

EmericD said:

Further reducing the ogive height from 23 mm to 20 mm for the T65 cartridge, while at the same time focusing on bullet penetration up to 1800 m, was really a bad move.

I understand why they did that, what I don't understand is why they seemingly made no effort to produce a streamlined bullet within that format. Even more bizarrely, the British made exactly the same mistake, and the 140gr Type C bullets for the .280 are no more aerodynamic than their .30 cal counterparts.

The only excuse - and it is a thin one - that I can think of is that during this time the science of supersonic aerodynamics was only just maturing, so maybe there wasn't enough institutional motivation? Certainly a large brain drain occurred in the Army after WWII, as those people left to go to the Air Force and private sector.

QuintusO

From: QuintusO

19/9/20

Sending this because I don't really trust private messages on delphi (they seem to get eaten a lot). I imagine you only check emails at your work address during the week, but I sent you some things yesterday I think you would find very interesting. I don't know if you can check it, or shoot me some other address I can forward them to.

EmericD

From: EmericD

19/9/20

QuintusO said:

Sending this because I don't really trust private messages on delphi (they seem to get eaten a lot). I imagine you only check emails at your work address during the week, but I sent you some things yesterday I think you would find very interesting. I don't know if you can check it, or shoot me some other address I can forward them to.

use the same address but with "@def.gouv.fr" for the domain.

QuintusO

From: QuintusO

19/9/20

Thank you. Sent.

In reply toRe: msg 46
autogun

From: autogun

26/9/20

Some more info about TV ammo posted on TFB.
 

TOP