26 replies to this topic

[Strum Wealh]

Karel Spaten, on 09 April 2012 - 02:25 AM, said:

Indeed.

For the benefit of those who've never operated a sustained fire weapon - the multiple barrels on a minigun are intended to reduce wear and tear on any one individual barrel. Burst fire makes gun barrels hot - if the barrel gets too hot, it will warp. This is bad. Standard single barreled machine guns usually have the means by which to remove and replace the barrel quickly if needed (keep swapping them, allow them to cool). WW1 and 2 era heavy machine guns often had water jackets to help keep the barrel cool. The minigun has a separate motor rotating them so only one bullet in [number of barrels] passes down the barrel at a time. Usually, only one barrel is firing at a time.

Alaskan Viking, on 09 April 2012 - 02:38 AM, said:

Of course they are gatling designs! A revolving cylander is just a primative means of storing cartridges in a firearm, a revolver has no faster firing rate then any other automatic loading mechanism. (such as spring loaded rounds from a vertical magazine column) The reason is that each time a round is fired from a gun the barrel heats up, eventually it will warp and the firearm will become inoperable this is true if the gun is a revolver or locking-breach design. This is usually countered in machine guns by water cooling systems, or air cooled barrels that can be changed rapidly. The gatling design is used in modern weapons because it disapates heat from the barrel faster. The rotating barrels share the heat among them and the movement circulates cool air around them faster...

SO WHY WOULD IT BE A REVOLVER?!?!?!

EDIT: I just noticed the post above this, which renders mine redundent...

Actually, revolver-type autocannons are real-world weapons, commonly used in aircraft since at least WWII.
Examples include the Mauser MG 213 and the Mauser BK-27 (Germany), the M39 cannon (US), the ADEN cannon (Britain), and the DEFA cannon and the GIAT 30 (France).

Quote

A revolver cannon is a type of autocannon commonly used as an aircraft gun. It uses a cylinder with multiple chambers, like those of a revolver handgun, to speed up the loading-firing-ejection cycle. Some examples are also power-driven, to further speed the loading process, but this is by no means universal. A revolver cannon differs from a Gatling gun in having only a single barrel, so the spun weight is lower and lends itself to gas operation. Automatic revolver cannons have been produced by many different European manufacturers, whereas the U.S., and to a lesser extent Russia, generally favor the Gatling gun.

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Automatic revolver cannons generally have a lower maximum sustained rate of fire than Gatling guns, as all the rounds are fired through a single barrel, which suffers from much higher heating loads. Cannon-calibre Gatling guns have a rate of fire of up to 10,000 rounds per minute or less, while revolver cannon typically have a rate of fire of up to 2,000 rounds per minute or less. On the other hand, revolver cannon generally have a high initial firing rate due to the lower moving mass involved – only the chambers are being spun. Gatling type guns spin the whole multiple barrel and breech assembly which in equal calibre versions can weigh hundreds of kilograms. Also, the external power source of US gatling guns provides less power in a burst than the gas-operation of a revolver cannon, so that about half a second of spin-up time is required until the maximum rate of fire is reached. As it avoids the additional weight of multiple barrels, a revolver cannon can fire a larger calibre projectile than a Gatling gun of the same weight.

That said, BT/MW Rotary Autocannons are multi-barrel, Gatling-type weapons.

[Uncle Totty]

So, UACs are revolver types then?

[CCC Dober]

@Strum

Yeah, just imagine a multi-barrel AC20 design, where each barrel is as thick as that of a standard AC20. The resulting total weight would easily double or triple. That said, single-barrel revolver style makes a lot more sense for the heavier ACs. More economical and technically feasible. I do wonder however, if the heavier UACs could be possibly done as double barreled standard ACs. That would look beyond awesome =)

[osito]

If i remember my lore right most original ac are single barrel cannons. They tend to jam and overheat in extended battles. So most newer ac used a multi-barrel system but kept the near same rate of fire of the original ac. This meant the barrel rotated after every shot allowing each barrel to cool. This lead to a lot less jamming and over heating. Now the rac took this to the next level by speeding up the rof and barrel rotation. Turning it into a massive Gatling gun. The problem it brought back the jamming and over heating problem the old ac had. But with the damage profile it can do has many warriors seeing it as a fair trade-off.

[Felix Dante]

William Petersen, on 09 April 2012 - 10:02 AM, said:

I'd take a RAC-5 for the sheer awesome points. B-)

I've been trying to sort a design that has a RAC-5 in each arm, decent ammo stock to keep them fed, while maintaining 5/8 movement, fieldable armour, and a few fall back MLas. It's not really working out. XD RACs are *heavy!*

Sorry, it just isn't possible. You can barely fit 1 RAC in a mech, much less two.

I was able to make an Inner Sphere based 100 ton RAC5 Annihilator with 4x RAC5s with 8 tons of ammo
and 3 MPLs. I used a Light Engine (Not an XL Engine) and it didn't have full armor. But it did work.
The main idea is not to use the rotarys at full speed until your hit numbers are low enough to make it a good idea.
This conserves ammo and prevents locking them up more often.

I have even used it in a couple of board games...Its mainly a defensive or city fighter with it's limited range.

I did make a Clan version that overcomes the range problem using Clan RAC5s, but have never tried it
on a battlefield yet.

[osito]

There are 2 jagermech variants that have 2 racs as its armament. The jm7-f is a upgraded 70 ton version with twin rac-5 as its primary armament. The jm7-g is the 65 ton version packing a pair of rac2's for its heavy firepower.

[William Petersen]

Felix Dante, on 09 April 2012 - 11:39 AM, said:

Sorry, it just isn't possible. You can barely fit 1 RAC in a mech, much less two.

I was able to make an Inner Sphere based 100 ton RAC5 Annihilator with 4x RAC5s with 8 tons of ammo
and 3 MPLs. I used a Light Engine (Not an XL Engine) and it didn't have full armor. But it did work.
The main idea is not to use the rotarys at full speed until your hit numbers are low enough to make it a good idea.
This conserves ammo and prevents locking them up more often.

I have even used it in a couple of board games...Its mainly a defensive or city fighter with it's limited range.

I did make a Clan version that overcomes the range problem using Clan RAC5s, but have never tried it
on a battlefield yet.

Actually, I just loaded up MegaMek Lab, and made a Timber Wolf with Max armour* and its traditional 5/8 movement with the following armament: a RAC-5 in each arm (4 tons ammo, total), 2 MPlas, 2 SRM-6 (1 ton ammo shared), and 1 ER SLas. I'm not sure what problem I was having before. Naturally I use an XL Engine, with ES internals and FF Armour for tonnage.

Obviously I couldn't get quite that much armament out of IS tech (since it's heavier), but still. Also, obviously a non-cannon design, and one I'd never actually be able to use in MW:O, unless they have a less-restrictive set of rules planned for Omnis, since no canon Timber Wolf variant has 8 Ballistic Crit slots in the arms.

But yeah, An ANH-2A with RAC-5s instead of LB-10X ACs would be pretty sweet. =) (And possible in MW:O, as the LB-10X and RAC-5 have the same crit slots). I think I'd swap the 4 PLas for 4 MLas (or 4 ER MLas), though. You can take 8 tons of ammo, another 2 heat sinks (filling your crit space to capacity), and then pack on another 2 tons of armour, of which the ANH-2A is in desperate need.

As a parting note, the ANH was *designed* as a defensive city fighter. But not because of it's range, rather because of its speed. The AC/10 actually has rather respectable range in Tech 1.


* = 230 actually, because the way FF armour works, I have to use a whole 'nother half-ton to get that last point. Worth it? Hell no.

Edited by William Petersen, 09 April 2012 - 01:57 PM.