Author Topic: velocity test of guns/cannon rounds (Read 2683 times)

Jigster · « **Reply #30 on:** October 31, 2000, 02:59:00 PM »

Quote

Originally posted by Hooligan:
I don't have trajectory data for Hispano rounds.

There shouldn't be much difference between the trajectories of most HE and AP rounds for the same guns. The reason that there is a big difference for the Mine round and the AP round is that the Mine round is much lighter (around 90g instead of 115g). All the conventional 151 rounds (including HE) that I have information on weigh about 115g and have similar G1-BCs in the range of .44 to .50.

Here are some BCs I have calculated.

45.9g .50 Ball .72
42.9g .50 AP/I .65

(all of the following 151 rounds weigh 115g except for the mine)
151 HE-tracer .48
151 HE-practice .44
151 HE/I .48
151 Incendiary .47
87g Mine .27
90g Mine .27

Concerning the Mauser's AP performance: The 151 AP round has a muzzle velocity of 705 m/s (compared to around 880 m/s for the Hispano or 928 m/s for the .50 AP/I). At short range a Hispano can punch through about 45mm of armor plate, while a .50 and 151 should both be able to punch through about 25mm. .50s don't do much to PzIV's either.

Hispano's do hit somewhat harder than the other cannons, but they should. They fire larger rounds at a much higher velocity. A Hispano AP round will go through most of the aircraft structure in addition to the pilot armor on any WWII fighter at any range at which you can hit.

Hooligan

[This message has been edited by Hooligan (edited 10-31-2000).]

Unfortunately the differences between an AP and HE round grow further apart with size.

As in the case of the Hispano HE round, it is lighter and has 10mm of flat surface area directly perpendicular to flight line (the fuse surface) that adds considerable drag to an already lighter round.

Nearly all of the Hispano HE's mounted Mk 26 fuse caps (on a Mk 7 explosive shell) with the flat nose. (from late '43 onward)

Granted most other HE cannon shells have the same type of fuse, they are generally not quite as large as the Mk 26's fuse cross-section.

Anyway, there is a signifigant difference in ballistics of the two shells.

The HE losses energy more rapidly at long range, and arcs. (not as much as the Mauser however) However,under about 300 yards or so, the flight paths are nearly identical.

Hooligan · « **Reply #31 on:** October 31, 2000, 04:21:00 PM »

Jigster:

Cool information:

I would love to get any hard information on Hispano rounds that you have. MV, weight, trajectories, explosive content, pictures etc...

I would be grateful if you would email me the information you have or the details of the source material so that I can obtain it.

Hooligan

Hooligan · « **Reply #32 on:** October 31, 2000, 06:48:00 PM »

Janjan:

Missed your question earlier. At higher altitudes projectiles keep their speed better. Presumably AH models this.

Hooligan

Toad · « **Reply #33 on:** October 31, 2000, 08:39:00 PM »

Nice post, Mav.

Hey, Fish...you ever grow enough hair to post the name you fly under?

------------------
Toad

If you want government to intervene domestically, you’re a liberal. If you want government to intervene overseas, you’re a conservative. If you want government to intervene everywhere, you’re a moderate. If you don’t want government to intervene anywhere, you’re an extremist.

-Joseph Sobran (1995)

Jigster · « **Reply #34 on:** October 31, 2000, 09:05:00 PM »

Pyro's got a picture of the 3 Mk 4 casing rounds somewhere in this forum.

Btw the differences between the two Hispano shells would only be apparent at long range, and is still much better then the MG 151 and ShVak.

- Jig

[This message has been edited by Jigster (edited 10-31-2000).]

Pyro · « **Reply #35 on:** October 31, 2000, 09:14:00 PM »

Niklas, I'm not sure how you made your observations, but I don't see anything that jumps out at me as being incorrect. Deceleration is not a linear function of distance, but that would only change how it looks inbetween the two points.

There is no issue of Hispano modeling being based on AP rounds while 151 rounds are based on HE. If that were the case, initial velocities would be almost identical, but velocity retention would favor the Hispano even greater.

------------------
Doug "Pyro" Balmos
HiTech Creations

Maverick · « **Reply #36 on:** October 31, 2000, 10:31:00 PM »

Fishu,

You must be a wonderful student for your teachers. I can just see you telling them they know nothing of the subjects they teach as you know it all already.

You lack experience, knowledge and maturity. Until you gain some of those you cannot claim any credibility on the subjects you speak of. In short, Grow up and get out in the world boy.

Mav

Fishu · « **Reply #37 on:** November 01, 2000, 01:32:00 AM »

Quote

Originally posted by Maverick:
Fishu,

You must be a wonderful student for your teachers. I can just see you telling them they know nothing of the subjects they teach as you know it all already.

You lack experience, knowledge and maturity. Until you gain some of those you cannot claim any credibility on the subjects you speak of. In short, Grow up and get out in the world boy.

Mav

Excuse me, but where are you referring to now?
You didn't answer to my question and you're talking me of teaching someone when I haven't been saying anything worth knowledge in last post.

I think your army career is same as discovery channel.

Ps. at least I will be going to army unlike some discovery channel fans who tells they've been in army.

Maverick · « **Reply #38 on:** November 01, 2000, 02:57:00 PM »

Quote

Originally posted by Fishu:
Excuse me, but where are you referring to now?
You didn't answer to my question and you're talking me of teaching someone when I haven't been saying anything worth knowledge in last post.

I think your army career is same as discovery channel.

Ps. at least I will be going to army unlike some discovery channel fans who tells they've been in army.

Fishu,

The allegation you make, that you "think" is highly suspect. I will say this. You are a very mistaken little boy. I will be happy to provide documentation to a neutral party that proves my service. Your statement is clearly a wild stab in the dark as you have no basis for it other than you mean it to be a defamatory remark.

The only statement you have made that is accurate is this one. "I haven't been saying anything worth knowledge in last post." You are absolutely correct there. You have not said anything with or worth knowledge in your post.

Now who shall the neutral party be that I will send my documentation to?

My nominations are:

Nexx - Britian
Dowding - Britian
Yeager - US
Hangtime - US
RAM - Spain
St Santa (I forgot your country of origin, sorry)

To any of those folks I will be happy to send documentation verifying my Army service. Would any of the named parties please confirm a willingness to be a neutral party in examining them?

Mav

[This message has been edited by Maverick (edited 11-01-2000).]

Fishu · « **Reply #39 on:** November 01, 2000, 05:57:00 PM »

You talk about maturity and 'little boy' things when you don't know anything about me and yourself just keep insulting me.. so whos losing some maturity here?

and back to the topic...
btw. you got little problem with 'army service' things.. I don't know about hispano, mg151/20 or shvak being used lately..
you might well know .50 caliber.. but we're not talking of it in here.

Maverick · « **Reply #40 on:** November 01, 2000, 06:29:00 PM »

You didn't answer the question fishu. Who is your nominee for neutral party. You have insinuated I have lied. I will not tolerate that especially from you.

Mav

Toad · « **Reply #41 on:** November 01, 2000, 06:53:00 PM »

"little boy things"?

At least Mav flies under his BBS posting handle. He's not afraid to be known to all in the arena.

Seems like people that hide their identity might have a little boy thing.

Fishu · « **Reply #42 on:** November 01, 2000, 10:47:00 PM »

Bah.. same as talking to the bricks

Mav, well.. you better begin tolerate such things, because you actually threw the first stone in that case.

Toad, if you read things above, you know why I fly as other.
I don't go into arena to hear BS from this sort of guys like mav etc.

Maverick · « **Reply #43 on:** November 01, 2000, 10:52:00 PM »

Fishu,

Here is a straight out statement for you. You have impugned my honesty and honor. Now either apologize or name your neutral party to examine the documentation. I am willing to prove my background. I am putting up right now. It is your turn to put up or shut up. Unlike you, I can prove it.

Mav

[This message has been edited by Maverick (edited 11-01-2000).]

Fishu · « **Reply #44 on:** November 02, 2000, 12:17:00 AM »

Quote

Originally posted by Maverick:
Fishu,

Here is a straight out statement for you. You have impugned my honesty and honor. Now either apologize or name your neutral party to examine the documentation. I am willing to prove my background. I am putting up right now. It is your turn to put up or shut up. Unlike you, I can prove it.

Mav

Err.. no deal.
I don't strike against other people unless they've done it to me first.
I see no reason to apologize anything because I haven't heard apologize from you, who started it.