gatnerd

Military Guns and Ammunition

Hosted by gatnerd

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

  • 3346
    MEMBERS
  • 190040
    MESSAGES
  • 3
    POSTS TODAY

Discussions

For Your Amusement   General Army topics

Started 15/9/21 by stancrist; 14516 views.
JPeelen

From: JPeelen

10-Aug

The calculator you link to, is on J.B. Millard's web page, a man who has made available very useful, previously unaccessible data to those interested lerning about small arms ballistics. 

The problem is clearly shown by the graph in Emeric's message. (Thanks a lot, Emeric.) The calculator on the JBM website is set up to handle the red (G7) and black (G1) drag curves (and a few similar others).

But the real drag of the round nose bullet is represented by the green curve. I think it is obvious that the red and black drag curves will not be able to correctly calculate a trajectory governed by the green curve, execpt at short ranges.  

It would of course be easily possible to make the green curve part of todays ballistic calculators. But nobody does it, because everyone thinks the black (French from around 1890) and the red (UK from WW2) drag curve are all we will ever need. 

In my opinion, the only improvement the green curve needs is expanding its base from a ingle projectile type and caliber to include other calibers and similar shapes.

Why do you think obtaining radar data for 6.5 Carcano is unlikely? Rifles and original ammunition of this type abound here in Europe. New cases (PPU, Norma) for mercury-free primers (a dominating consideration over here) are readily available. The same applies to 7.35 Carcano, by the way. I have a rifle, more than a hundered rounds and also modern PPU cases. All we need is a management decision that says: "We want to examine this green curve further, because its unkown territory in ballistics and to know ballistics is our job."      

P.S.: Not to be misunderstood, the last sentence does not have the institution where Emeric works in mind, but any institution that considers exterior ballistics as its domain.                   

  • Edited 10 August 2022 16:53  by  JPeelen
stancrist

From: stancrist

10-Aug

JPeelen said:

Why do you think obtaining radar data for 6.5 Carcano is unlikely?

I would opine the answer to that question is in your next sentence:  "Rifles and original ammunition of this type abound here in Europe."

6.5 Carcano was developed long before radar testing became available.  There has been ample time and opportunity to obtain the data.

Despite still being used in abundance, there has apparently been no interest in getting radar data for it.  Otherwise, we'd already have it.

For a more authoritative answer, I'd suggest that you ask Emeric why his institution has not bothered to obtain radar data for 6.5 Carcano.

JPeelen

From: JPeelen

11-Aug

Thank you for your thoughtful off-topic advice. In my mind, air drag figures of older bullet types are at the core of our exchange, not motivations of institutions.  Anyway, Emeric's institution and he personally have to be lauded for doing something of substance in this matter.     

  • Edited 11 August 2022 2:12  by  JPeelen
stancrist

From: stancrist

11-Aug

JPeelen said:

Thank you for your thoughtful off-topic advice.

Not sure why you feel the need for sarcasm.  I gave an honest answer to your question.  However, as it was just opinion/speculation based solely on my observation and analysis, I suggested you ask Emeric since he may have firsthand knowledge of why his institution has not obtained radar data on 6.5 Carcano.

JPeelen said:

In my mind, air drag figures of older bullet types are at the core of our exchange, not motivations of institutions.

Motivations of institutions appear to be the reason for absence of the data you want.

EmericD

From: EmericD

11-Aug

JPeelen said:

It would of course be easily possible to make the green curve part of todays ballistic calculators. But nobody does it, because everyone thinks the black (French from around 1890) and the red (UK from WW2) drag curve are all we will ever need.

The "Oehler Ballistic Explorer" v6 software is able to use custom drag curves, for only 80 USD it's one of the most useful program that you can buy.

JPeelen said:

All we need is a management decision that says: "We want to examine this green curve further, because its unkown territory in ballistics and to know ballistics is our job."

Unfortunately, "unknown territory" is not enough to induce interest, unless we start fielding cartridges with round nose bullet again.

JPeelen

From: JPeelen

11-Aug

There is even a high quality, free-of-charge program which accepts individual drag models. The author is  professional ballistician Jan Krcmár, Ph.D., formerly of ISL. It can be downloaded from ballistics.eu 

Indivdual drag models can be input as text files. Same format as used by the Broemel program QuickLoad. Because I liked it, I wrote an English and a German indroduction, both also downloadable from the website.       

In reply toRe: msg 81
schnuersi

From: schnuersi

18-Aug

Recently I have realised that the 6,5 Swedish when loaded with the 9 g service spitzer boat tail is pretty close to the .276 Pedersen.
If loaded with a 8 g spiter boat tail its MV and ME are for practical purposes identical. Concidering the smaller diameter of the bullet would the 8 g 6,5 perform better? It seems likely that it would be better at range.

It also raises the question if the Swedes have been sitting on a near ideal infantry cartridge all along without realising.

stancrist

From: stancrist

18-Aug

Perhaps they did realize it.  6.5x55 AP reportedly had a 7.3 g spitzer boat tail.

The Swedish Military Ammunition Site (amkat.se)

graylion

From: graylion

18-Aug

schnuersi said:

It also raises the question if the Swedes have been sitting on a near ideal infantry cartridge all along without realising.

If I was the EU and was integrated enough to standardise a rifle catridge, I'd probably go 6.5x47. Kurz und dick ... ;)

Farmplinker

From: Farmplinker

18-Aug

Didn't Moltke want the German army to go to a lower powered 6.5 pre-WW1?

TOP