I have finally finished this. This gun is one of my most accurate creations, based on its mechanisms and bullet speed. Also, it uses the ImpactForce from the gun weapon (credit to SnoWFLakE0s, I guess)because I had trouble with the reloading and stufff. So this doesn't really work like my other guns.

Also, since school is starting again, this might be my last in a while. Soooo, sorry to all those who asked for tanks(like the MarkIV and Panzer) and guns, because I will not be able to post. Anyway, that was pretty long sooo, here ar the instuctions:

How to activate:

When you have picked an appropriate place(flat gound), Activate AG7. This arms the shell inside the gun and activates the elevation and rotation.

How to Fire:

Press FireGuns(space bar)

How to Reload:

Deactivate AG 7(to set the gun)
Deactivate AG 8(to open the breech)
Retract Landing Gear(to clear the breech; wait for the propellant casing to fall out)

Extend landing gear(don't forget)

Activate AG1,2, or 3(depending on which shell you want to load; I advise loading the first shell first which is AG1)

AG8(close the breech)

and you are ready to fire(FireGuns)

Movement is just like my other tank builds.(It is advised not to move to much when a shell is loaded)

P.S. This is not a self propelled artillery. I just place an engine so you could move. If you want a more realistic one:

https://www.simpleplanes.com/a/kIp75p/203mm-B-4-with-Tractor

203 mm howitzer M1931 (B-4) (Russian: 203-?? ??????? ???. 1931 ?. (?-4), GRAU index 52-G-625) was a 203 mm (8 inch) Soviet high-power heavy howitzer. During the Second World War, it was under the command of the Stavka's strategic reserve. It was nicknamed "Stalin's sledgehammer" by German soldiers. These guns were used with success against Finnish pillboxes at the Mannerheim Line, heavy German fortifications and in urban combat for destroying protected buildings and bunkers. This weapon was used until the end of the war in the Battle of Berlin where the Red Army would bring these guns up at point blank range to smash German fortifications with their heavy 203mm shells. In the spring of 1944, a KV-1s tank chassis was used to create a self-propelled variant, the S-51. The heavy recoil from the muzzle blast threw the crew off their seats and damaged the transmission, and so it was cancelled.

With an elevation angle of up to 60 degrees and 12 propellant loads to choose from, the B-4 virtually met all the expectations it was given, capable of crushing its targets via an optimal projectile trajectory.