Gunsight bad feeling

[vgilsoler]

Probably it's me and not the gunsight or a bug, but more I practice with the mig15 more bad feeling I have with the gunsight (fixed or gyro doesn't matter)

I used to fly with warbirds (FW190D9, P51D or P47D) and I'm not an ace but I can shutdown a B17, Ju88. C47 or straffing with guns using a reasonable amount of ammo. But with Mig15...I'm starting to think there is something wrong with the gunsight or with the guns.

I attach a track of a training mission trying to fire a C47 and a B17.

practice_mig15_gunsight.trk

[Art-J]

Mate, if you want people to watch a bug-reporting-track, especially developers who have dozens of tracks to investigate daily, you better make it a short, airstart mission already near a target. Watching you sitting on a runway and tinkering with radios and radio-compass is not what guys want and need to sit through. Luckily, your track doesn't de-sync with time acceleration, so it's easier to fast-forward to gunnery parts.

Back to the topic, please keep in mind that:

a) Both cannon types on MiG have noticeably lower muzzle velocity compared to guns you are used to in aforementioned 3 warbirds up to that point. Between about 670 and 690 m/s which is quite low (albeit If you ever buy 109-K4 module, then you will see what a REALLY low muzzle velocity cannon is  . Good luck trying to hit anything with MK-108 beyond point-blank ranges). As such, they require more lead while aiming. Low rate of fire of 37 mm gun makes things even more challenging.

b) ASP gyro gunsight on MiG is supposed to work only  when both you and target turn SMOOTHLY at low G, or preferrably - target flies straight. You're not supposed to use it closer than 180 m either. That AI C-47 pitching up and down like crazy wasn't the best platform to test (although it would be annoying target in any fighter I think).

In either case, who knows, it's possible that recent changes to F-86 gunsight had some negative, inadvertent side-effect on MiG as well. Or maybe gyro sight issues are just "normal" in old Belsimtek-developed modules - I've read that the one in F-5 isn't great either, but I don't own that module to confirm. 

The only way to check it properly is to do the same what was requested by devs during F-86 gunsight investigation - set up a mission with loitering target, constant G, constant speed (like in MiG-15 gunsight tutorial). Turn wake turbulence off and icons on for precise distance measurement. See if gunsight in gyro mode can calculate correct lead at, say 200 and 300 m. If it doesn't - save a track and create a thread in bugs section.

Edited November 25, 2023 by Art-J

[vgilsoler]

Thank you for reviewing the track and the comments.

As I said before, at this moment it's more bad feeling when shooting with the Mig-15bis than thinking there is a bug. I wanted to know if for other users it was the same, or not.

 

[WinterH]

Been a while last I did anything with the MiG, so you may well be right but, I'd echo the other poster in mentioning the difference in guns.

.50 cals on US warbirds are so flat shooting they might as well be laser beams, 13mm + 20mm combo on Fw-190 is a bit less so, but still fairly flat shooting with pretty good muzzle velocity. Also while they are two different gun types on the 190, their ballistics are fairly similar up to reasonable dogfighting ranges.

23mms and 37mm on the MiG are really not flat shooting weapons, they both leave something to be desired when it comes to velocity. Also, unlike the all .50 cal setup on American birds, or 13+20mm on Fw-190, ballistics of 23 and 37s on the MiG are very different if you want to shoot them together in anything further than just beyond point blank. 

So unless your targets perfectly still, and you are quite close, they will require more deflection than you are used to with the other birds.

[Art-J]

I also don't fly MiG often, so just out of curiosity I did two test flights again:

a) Gunnery tutorial mission, which makes you follow the shallow turning Sabre at a meager 1.5-1.7 G;

b) BigNewy's gunnery test mission from F-86 gunsight investigation thread, only with Sabre replaced by MiG. In this one you follow tighter turning Su-27 at 2.5-2.8 G.

In the former test, gunsight in gyro mode worked very well actually, at least in moderate ranges of up to 400 m. The only problematic thing was figuring out if I should "catch" the target with outer of inner diameter of reticle "diamonds ring", that's why I enabled full unit labels for better distance measurement. Tip - turns out it should be neither inner not outer, but somewhere inbetween.

In the latter test, the gyro mode was crap really and couldn't properly compute lead, even when still within reticle movement limits. I had to pull much more lead myself to hit the target eventually. 

I can post tracks if anyone's interested. Looks like the gyro mode is OK only for really smooth and low G maneuvers and close distances. Otherwise, gunnery in this plane is certainly more challenging than in other ones with more flat-firing guns. The 37 mm is bad, especially. Feels like lobbing watermelons rather than shooting air-to-air weapon  .

 

[AeriaGloria]

I can make track when I get home, but last time I flew MiG-15 I noticed that gyro sight corrects for NR-23 G acceleration correctly, but not ballistically. 

In gyro mode; if you get behind a level non turning target, and change range, the pipper does not move up and down at all to account for range, only G acceleration. 
 

So if I use Gyro sight, I must still correct for ballistic drop of NR-23. I would think this incorrect, so maybe I have some MiG-15 manual translating to do. I presume this is why you needed to place target between center of pipper and outer ring, the ballistic compensation is not there. 

On 11/27/2023 at 8:16 AM, Art-J said:

I also don't fly MiG often, so just out of curiosity I did two test flights again:

a) Gunnery tutorial mission, which makes you follow the shallow turning Sabre at a meager 1.5-1.7 G;

b) BigNewy's gunnery test mission from F-86 gunsight investigation thread, only with Sabre replaced by MiG. In this one you follow tighter turning Su-27 at 2.5-2.8 G.

In the former test, gunsight in gyro mode worked very well actually, at least in moderate ranges of up to 400 m. The only problematic thing was figuring out if I should "catch" the target with outer of inner diameter of reticle "diamonds ring", that's why I enabled full unit labels for better distance measurement. Tip - turns out it should be neither inner not outer, but somewhere inbetween.

In the latter test, the gyro mode was crap really and couldn't properly compute lead, even when still within reticle movement limits. I had to pull much more lead myself to hit the target eventually. 

I can post tracks if anyone's interested. Looks like the gyro mode is OK only for really smooth and low G maneuvers and close distances. Otherwise, gunnery in this plane is certainly more challenging than in other ones with more flat-firing guns. The 37 mm is bad, especially. Feels like lobbing watermelons rather than shooting air-to-air weapon  .

 

 

[some1]

Maybe this is the issue: https://forum.dcs.world/topic/341945-gunsight-ranging-is-incorrect/#comment-5366855