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Military Guns and Ammunition

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

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NGSW Phase 2 Consolidation and info   Small Arms <20mm

Started 30/8/19 by gatnerd; 553302 views.
roguetechie

From: roguetechie

15/8/21

The entire grenade launcher example was deliberately meant to be as absurd and exaggerated as possible while still illustrating why time of flight matters.

This is what we've been arguing about right?

It's meant to illustrate how time of flight:

1. Is actually important

2. Only somewhat correlates to muzzle velocity

3. Because muzzle velocity only somewhat correlates to time of flight, it must necessarily mean that there is at least one other factor which affects time of flight.

4. There are in fact multiple other factors that inform a round's time of flight between the muzzle and a target.

5. Time of flight whether you're talking about mortars grenades or rifle bullets DOES MATTER.

This is why I picked 40x53 vs 25mm xm25. In that comparison you have all 5 of these points kinda more clearly shown in ways that are obvious to someone than you do in something like a rifle bullet.

So let's keep working with this 40x53 mk47 versus xm25 comparison because it's already here.

We can see that even though the US already has mk47's fancy sights and all they still for some reason want basically xm25 2.0.

The justifications listed pretty much talk about the fight from 1000 meters inward.

On paper the mk47 should already cover 1000 meters inward right?

Then why do they still want yet another thing that appears to cover only a small fraction of what mk47 covers?

At this point you brought up muzzle velocity which is not time of flight.

Because muzzle velocity does not actually = much less function as a passable stand in for time of flight, it took the entire conversation off the rails and now everyone is confused. (I will not apologize for saying that you missed the point entirely here and this is incredibly frustrating)

There is still a reason why they want something more xm25 like when they already have mk47 with the cool gunsights even though it would appear that an xm25 like thing will have vastly worse stats on paper. It has a smaller blast radius, can't reach as far etc etc and even worse is that just looking at paper stats like MV etc the xm25 appears to be basically the same thing only worse and more limited!

Yet in reality the xm25 and mk47 are different weapons that do entirely different things even though on paper they can at first glance appear to be broadly similar with the xm25 being all around worse and more limited.

The xm25 may start with the same or even less muzzle velocity for all that this matters in the slightest, it's trajectory and time of flight though are so different that you get much different performance from it all the same!

You can do things with an xm25 you just can't with a mk47 and the reverse.

This is why they started the process of potentially resurrecting the xm25 in 2020 even though they already have the mk47.

If time of flight and it's much more closely correlated than muzzle velocity factor of trajectory by extension really didn't Matter you just outright wouldn't even see calls for something more xm25 like to be procured when the mk47 is already being used.

Again I'll point out that In my initial post I deliberately said Im going to use this as an absurd example that illustrates my point wrt time of flight and this comparison does do exactly that.

Time of flight and trajectory don't even appear in the star blocks most people use to compare and contrast a given weapons system or caliber against another and thus in most people's minds these can't possibly be a major factor that could determine the suitability or unsuitability of a given gun or caliber.

This is outright wrong.

They are some of the bigger driving factors that can differentiate between things that appear similar on paper now but in reality are world's apart.

QuintusO

From: QuintusO

15/8/21

I asked him about it and I didn't understand his explanation so I give up lol.

stancrist

From: stancrist

15/8/21

roguetechie said:

We can see that even though the US already has mk47's fancy sights and all they still for some reason want basically xm25 2.0.

The justifications listed pretty much talk about the fight from 1000 meters inward.

On paper the mk47 should already cover 1000 meters inward right?

Then why do they still want yet another thing that appears to cover only a small fraction of what mk47 covers?

Because (as I said in my response to your original post) the Mk47 is much too heavy and bulky for the purpose. 

They want a weapon that, like the XM25, can be carried and operated by one man.  That fact is clearly stated in the RFI:

-------------------------------------------------------

The PGS is envisioned to be a man portable integrated weapon system that enables precision engagements to destroy personnel targets in defilade and in the open with increased lethality and precision compared to the legacy M203/M320 grenade launchers.

  1. Maximum overall system length not to exceed 34 inches.
  2. System weight not to exceed 14.5lbs.

SAM.gov

-----------------------------------------------

EmericD

From: EmericD

16/8/21

roguetechie said:

The entire grenade launcher example was deliberately meant to be as absurd and exaggerated as possible while still illustrating why time of flight matters. This is what we've been arguing about right?

I don't know if "arguing" is the right word.

A US designed HEDP 40 x 53 mm grenade needs 6.49 sec to reach 1000 m. What is the ToF of the 25 x 40 mm at this same distance? Even using the better FF of the 25 x 59 mm, I can't do better than 6.55 sec.

  • Edited 16 August 2021 3:13  by  EmericD
stancrist

From: stancrist

16/8/21

FYI -- This is the only statement in the RFI about time of flight:

After trigger pull, time of flight to target no greater than 3 seconds to 500 meters.

SAM.gov

DavidPawley

From: DavidPawley

16/8/21

Epic troll

Sten556 said:

Trying to steal the limelight of the superior caliber by taking its name is the sort of underhanded tactic the Grendel cabal used to kill off the competition.

Well played.

stancrist

From: stancrist

16/8/21

roguetechie said:

Again I'll point out that In my initial post I deliberately said Im going to use this as an absurd example that illustrates my point wrt time of flight...

Baloney.  You said no such thing.

Here is what you actually wrote:

"We see this issue much more acutely with grenade launchers whether they are LV or HV so I'm going to use them as an example.

The US military right now is looking to buy something like the xm25 again because they need an HE flinger to service urgent targets up to 1000 meters. So why would they be looking for something with a much shorter time of flight and higher velocity even at the cost of drastically reduced explosive payload and blast radius when they have the fancy striker AGL with very advanced grenade sights which can reach out to way past 1000 meters Tony?"

https://forums.delphiforums.com/autogun/messages?msg=7519.1248

EmericD

From: EmericD

16/8/21

stancrist said:

FYI -- This is the only statement in the RFI about time of flight: After trigger pull, time of flight to target no greater than 3 seconds to 500 meters.

The ToF of the US 40 x 53 mm HEDP is 2.78 sec at this range (500 m).

DavidPawley

From: DavidPawley

16/8/21

roguetechie said:

between a 22 and 24 inch barrel that does oh let's say no more than 2600 fps and is let's just call it between 270 and 280 caliber.

Ha. Sten556 is your sock puppet! I see it all now.

roguetechie

From: roguetechie

16/8/21

I wish I was that talented.

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