Does altitude affect weaponry?

[Torquila]

I made a gunsite for my 410 and it works great on the deck, but at 25k the bk5 isnt hitting where it "should".

Is this modelled?

[branch37]

from what i've seen, bullets fly straighter at high altitude due to the thinner air.  Thinner air=less bullet drop

[Torquila]

Yea, thats basically what I saw; I was hitting b26's 1.5 out with just putting my crosshair center on them at 25k (convergance 650)

[bustr]

Yes, rounds hit higher becasue they drop less in the lower density air. I think I know one of the sources HTC uses for the US 20mm in the P38's.

20mm HEI MkI
IntV = 2,700 ft\sec
Sea Level 300TA 1333yds drop 698 inches 2.2sec
30,000ft `300TA 1333yds drop 405 inches 1.53sec
50,000ft `300TA 1333yds drop 357 inches 1.4sec

Why don't you spend the time getting to alt offline and perform screen captures auto level against the target at 25K? The german data for the 5BK was pulled at ground level at Rechlin. I've never seen german docs for drop at other alts. Who knows maybe Hitech can post his formula so you can calc the difference in Vloss time\drop due to air density. For a 2.5k shot your aimpoint is about (-25Mil). One of my squadmates was hitting B17 at about 27K over the strats with a Revi I modified with a numbered Mil ladder. If you downloaded my latest gunsight pac you have a tool in it to aid you in your offline shooting. All of those gunsights are 512x512 1Mil = 2Pixel. Makes it easy to add in Mil ladders later on.

[Lusche]

Yes ,alt effects are implemented.

HiTech

[bj229r]

affect

[SmokinLoon]

A quote from Hitech from 7 years ago.  Nice.   

This is the type of thing that should be a part of any gunnery tutorial in the AH Trainer's Website.

The other thing is I wonder just how much difference trajectory is in a .50 cal at 25,000ft vs sea level.  Is it enough for fighters to change convergence ranges?  I've not ever really taken too much of a notice, but now I will. 

[WyoKId]

affect

effect....affect is a facial expression

[bustr]

US .50 cal AP M2 2700ft\sec

`SL drop at 1000ft 000ta is 30 inches time .4sec
`SL drop at 1000ft 300ta is 21 inches time .34sec
`7k drop at 1000ft 300ta is 21 inches time .34sec
15k drop at 1000ft 300ta is 21 inches time .34sec
30k drop at 1000ft 300ta is 21 inches time .33sec
50k drop at 1000ft 300ta is 20 inches time .32sec

US .50 cal API M8 2870ft\sec
15k drop at 1000ft 300ta is 18 inches time .32sec

You realy should test offline to see what your dispersion is at different ranges. In theory Hitech is modeling something like a 4Mil cone of dispersion out to the max range of each round 30mm and smaller except for the Mk108 which is more like 40Mil@1000yds. Even when you have that pipper dialed in from offline testing. If Hitech is going with the minimum of a 4Mil cone thats 12 feet at 1000 yards. The 5cm round closest to what the 410 is shooting has about a 15ft dispersion at 1000yards with a 15ft drop. But, getting out to 2000 its about 75ft by 140ft. The offline target is 180ft in diameter. (.target 2000 360 359) your 2000yd shot won't fall below the bottom edge of the target.

[Lusche]

Quick test:
At 300ft, the maximum range of he .50 cal (shooter and target stationary) is about 1150 yards. At 30,000ft, the max range turned out to be ~1400 yards.

[RSLQK186]

And here I was thinking strat runners were just more practiced in catching my egress from a guns pass on them. I try to intercept before they are in bomb site , so that is in their favor as well. But knowing that "point and shoot" and for a farther distance out is working for them at 25K explains some of my bad fortune.
Probably will not change my K4 tactics though. Man, I love that plane. 

[bj229r]

effect....affect is a facial expression

http://public.wsu.edu/~brians/errors/affect.html

[tunnelrat]

http://public.wsu.edu/~brians/errors/affect.html

"Yes ,alt effects are implemented."

That is the correct usage of "effects".

If he would have said "Yes, alt affects bullet trajectory" then affects would be correct.

[Mar]

"Yes ,alt effects are implemented."

That is the correct usage of "effects".

If he would have said "Yes, alt affects bullet trajectory" then affects would be correct.

bj229r was talking about the title of the thread.

Before Torquila made the edit, the subject line was incorrect.

"Re: Does altitude effect weaponry?"

[tunnelrat]

bj229r was talking about the title of the thread.

Before Torquila made the edit, the subject line was incorrect.

"Re: Does altitude effect weaponry?"

I think the real winner here is the English language.