The United States recently sent Lebanon 72 M198 155mm howitzers and 25 million rounds of ammunition (mostly for rifles, but also thousands of mortar and 155mm shells). The U.S. valued the shipment at $25 million but that was being generous. The Americans began replacing their 1980s vintage M198s with M777s in 2007. Thus the United States has lots of M198s that were going to be scrapped or put in storage (and eventually scrapped). Artillery is much less in demand since the 1990s because of the development of cheaper and more accurate guided rockets and artillery shells. That said, the Lebanese were grateful for the American howitzers since these are still useful and Lebanon received them as a gift.
Until recently the M198 was the standard towed 155mm howitzer for the United States and many NATO counties. Each one weighs eight tons, and can fire conventional rounds as far as 22.4 kilometers. For rocket-assisted projectiles the range is 30 kilometers. These unguided shells land anywhere within a 200 meter circle. That's at 25 kilometers range. Accuracy gets worse at longer ranges. It takes 12 minutes for the M198 to be ready to fire after the truck towing it stops. It can pack up and move again in about 4 minutes. Using GPS the M198 can be in position to fire in less than ten minutes and shift to another target in about 8 minutes.
The M198 has been replaced by the M777A1 lightweight 155mm howitzers. The M777s cost $1.9 million each and the U.S. has bought 800 of them so far, for use by the army and marines (who are getting 377 of them). The manufacturer, BAE, has also received a contract to refurbish 33 M777s that returned from service in Afghanistan. This cost $91,000 per howitzer. The British designed howitzer is also used by Canada and Britain. The U.S. Army uses M777s in airborne and Stryker brigades. A five ton truck is used to tow the guns, but a special, 4.5 ton LWPM (Lightweight Prime Mover) is available to do that as well.
The five ton M777A1 is 40 percent lighter than the weapon it replaces, the M198. This is because the M777A1 makes extensive use of titanium, and new design techniques. It fires shells with a maximum range of 40 kilometers (using RAP, or rocket assisted projectile, ammo). A crew of five operates the gun, which can be ready to fire in under three minutes, and ready to move in under two minutes. The M777A1 is light enough to be moved (via a sling) by CH-53E and CH-47D helicopters. Its sustained rate of fire is two rounds a minute, with four rounds a minute for short periods.
What will really makes the M77A1 (and the M198) useful is the new GPS guided Excalibur shell which entered service in 2007. The Excalibur shell falls within a ten meter circle (the middle of that circle being the "aim point") at any range compared to the unguided shell that lands within a 200 meter (or larger) circle depending on range. The Excalibur shell is essential, because ten 155mm shells (of any type, with their propellant and packaging) weigh about a ton. Ammo supply has always been a major problem with artillery, and Excalibur is the solution making one shell where previously ten or more unguided ones were needed.
For users like Lebanon ammo supply is less of a problem because the howitsers will be operating within tiny Lebanon and never that far from a port or airbase were new supplies of ammo will arrive. Besides the U.S. isn’t giving any of the expensive Excalibur shells away.