So why does the M1 Abrams platform use a smoothbore gun? I find it confusing that most modern projectile weaponry uses rifling but for some reason this does not. I know the cannon is still accurate but wouldn't it make more sense to be even more accurate with rifling?
The only downside to rifling that I could think of would be that eventually the projectile is going to sway in the direction of the rifling, however I didn't think with such a short travel time it would be noticeable.
Also I couldn't find a tank general thread to ask this in so I apologize if I just missed the thread.
>So why does the M1 Abrams platform use a smoothbore gun?
Longer barrel life, cheaper HEAT and sabot rounds. Drawbacks being accuracy and more expensive HE-shells.
>Easier to rifle the projecticle.
Are you stupid or something. Ammunition for smoothbore tank guns is fin stabilized.
You're missing a puzzle piece in your brain necessary to making sense of this mystery and it's okay, I'll provide it. Projectiles fired from big guns like those on tanks operate quite differently than a regular bullet. You don't need to grab grooves and spin the projectile when you can literally put tiny foldable wings (self deploying stabilizer fins) on the projectile. The fins provide a similar stabilizing effect to that which you would get from the spinning bullet.
These projectiles also are made of more than just metals. No copper jacketed lead solids here, were talking active explosive payloads. Some of which have a serious problem with spinning. Essentially, projectile tech has gotten to the point that rifling is now obsolete in some applications. Not in general but for this system, it is. More than likely, we'll see further advancement in guided projectile tech and continue to move away from rifled barrels, at least in large applications like this.
1) HEAT rounds get fucked up by spinning from rifling. HEAT is useful against many different targets.
2) SABOT can get kinda fucked by spinning from rifling. There's ways around it* but whatever.
3) accuracy with modern FCS and APFSDS is enough that smoothbore is fine.
*the brits still use rifled barrels because of their fetish for HESH ammo. Their Sabot is some special design that works with rifling.
Go read a few years worth of technical posts on Tanknet and come back later. There you have people with access to scientific papers and know what they are talking about, which you won't find on /k/
Sabot isn't an acronym, fucktard, it refers to the device which holds the penetrator in place and flies away upon leaving the muzzle in its discarding form. It's APFSDS or APFSDS-T
the real difference as far as i can tell is the speed of projectile. under a certain speed (and thus range and penetration) rifled barrels are more economic more foolproof. but after a certain speed the rifling becomes a hindrance. that is why for some guns it works great for others smooth-bore is better.
The K1 is old, the K1A1 uses the KM256 120 mm smoothbore gun.
You also get higher velocity. Which increases range and penetration. Not sure of the actual numbers, or if they are even meaningful in size, but they are there.
That doesn't make it any less of a projectile. And it uses a shaped charge.
Also, I'm pretty sure the 3UBK10 round containing the missile loads as fast as an ordinary round. It's SALH guidance, no need for wires.
Besides, neither the Obus G nor the 3UBK4 are missiles.
Wouldn't say range is a benefit to rifled, as the rifled ones have issues with HEAT shells, HEAT shells being (as far as I know) the best shell for long range in most situations.
HEAT fin stabilised shells has their own issues. Mostly losing stabilisation and accuracy at low speeds at extreme ranges. This why french developed guffy rotation stabilised HEAT round >>28448790 for their gun with internal core mounted on the ball bearings.
So what are some of the weirder tank rounds out there? HESH has always appealed to me because squash is a funny word and canister shot is also amusing, has anyone tried anything like a fuel air bomb with a big pneumatic pump on the front of the shell forcing fuel into the atmosphere upon impact and then igniting it like a mini MOAB?
Because once your projectile`s length:diameter ratio goes above a certain point, fin/drag stabilization becomes more effective than spin.
If small arms had a projectile 10 times longer than its diameter, it would probably be better to use a smoothbore.
The rifling is to stabilize the projetile.
Modern projectiles stabilze themselves, they have little fins.
Also like the other anons said it makes the gun more durable and versatile.