PERM Test Firings for 120mm EFSS

A couple years ago, URR posted this introduction to the Marine Corps combat use of the rifled 120mm mortar Expeditionary Fire Support System.  It’s light weight (relative to other fire support options) has led to its adoption as the primary direct support indirect fire weapon in Marine artillery regiments.

One major potential shortcoming of the EFSS is its short maximum range of about 8500 meters. Given that shortcoming, the Marines began the development of PERM, or the Precision Extended Range Munition.

PERM is a guided mortar designed to provide greater precision and wider range than existing ballistic mortars.

Not only does the use of a guided munition increase the first round accuracy of a shot, the fins allow the trajectory to be shaped to dramatically alter the path of the round, greatly extending the range, to a quite respectable 17,000 meters or so.

Last month, Raytheon, the developer, fired four PERMs in successful tests. An additional 42 rounds of test firing are due this year. If successful, the PERM should begin to show up on the caissons of the EFSS shortly thereafter.

Tank Battles

I’m feeling poorly today, so here a “best of..” post from way back in the very early days of the blog.

I wrote earlier about bringing enough gun to the fight, but not too much. A prime example of this was the M-1 Abrams tank.

When this tank debuted, people were aghast at the cost. What they didn’t realize was it was acutally the result of an extreme cost cutting program. For 20 years, the Army had been cooperating with Germany to develop a sucessor to the M-60 series of tanks, but each iteration had become too complex and too costly. The Army finally decided that they would develop a tank using technology shared with the Germans rather than develop a tank to be used by both countries.

One of the sticking points was the main gun. The standard US tank gun was the 105mm M68. The Army thought this was sufficient to defeat current and projected Soviet armor (and were pretty much right).

The Germans had developed the excellent 120mm smoothbore, and wanted both countries tanks to use it. Our Army resisted for a couple of reasons. The biggest was cost. The new gun would have to be license produced here, with associated setup costs. Even more expensive would be providing stocks of ammunition for the gun. The Army had a huge stockpile of 105mm ammunition already. Buying an entirely new stockpile in the tight budgets of the 1970s wasn’t an attractive option.

In the end, the 105mm won-sort of. The decision was to place the M-1 into production with the 105mm, but make provision to add the 120mm in the future. As it turned out, for various reasons, this was a lot harder than anyone expected. Still, partly as a sop to our German allies, and partly over concern about the ability of the 105mm to defeat future Soviet armor, the 120mm was adopted for the M1A1 that entered service in 1988.

One disadvantage of the 120mm was a reduced ammo load. An M-1 with the 105mm carries 55 main gun rounds. An M-1A1 carries 40. As it turns out, however, few tanks will shoot their entire basic load in a single battle. In fact, not a single tank in Desert Storm fired its entire basic load.

Tankers, ever wonder why the coax on your tank has that massive 4000 round load? Because that’s where the designers originally wanted to put the 25mm M242. The only reason it didn’t make it into the final design was cost. Leaving the 25mm out saved about $100,000 just for the gun, and made the fire-control system simpler, and hence cheaper. 

Good News for 11C’s

The Army has been trying to come up with a workable guided mortar round for about 20 years now. It looks like the time has finally come:

The Army is fast tracking a GPS guided 120mm mortar round to Afghanistan in response to an urgent request for precision mortar fire from commanders on the ground there, and should be fielded by the end of the year. Called the Accelerated Precision Mortar Initiative (APMI), it improves upon the current round’s 136-meter Circular Error Probable (CEP) reducing it to about 10-meters.

That’s good news for grunts on the ground. The 120mm mortar is the battalion commander’s “hip pocket” artillery, and it packs a good punch. The problem has always been that mortars are not terribly accurate. Their high angle of fire and their low velocity leaves them vulnerable to wind drift, among other things. This, of course, addresses that.

There’s another consideration. Most of the time, if the first mortar round doesn’t drop right on the enemy’s head, he’s got some time to seek cover. Now, he’s liable to be caught in the open with the first round, which greatly increases the chances of killing them.

Flikr goes Green

Many of you have an account with Flickr, the image hosting site owned by Yahoo!

Did you know the US Army had a Flickr page? One of my consistent complaints about the Army’s public affairs efforts is that they have a ton of people taking great photos, but rarely do people find any good pictures. Yes, there are a ton of pictures of things less interesting, such as the Secretary of the Army watching the first day for cadets at West Point. But there are also some great photos of soldiers in their natural environment. You just have to dig a little to find them. Here’s a taste. Click on each to enlarge:

Here’s a little more “Boom” for you.

It’s a mashup of some footage from Iraq. Most of this looks to be from 2004 or early 2005. There’s some small arms, Bradleys, TOWs, Javelins, AT-4s and 500lb bombs. Interestingly, there’s a brief bit of Blackwater MD530 helicopters.


H/T: Military Videos.

HEAT Rounds and Sabots redux

I don’t know why I spent all that time typing about HEAT rounds and sabots when National Geo covered pretty much all the high points in just over two minutes.


H/T: From my position…

Warheads on Foreheads, redux

We’ve seen a similar video before, and couldn’t resist stealing this one from the Armorer over at The Castle. There is, not surprisingly, a good deal of NSFW language, so you might turn down the volume, or wait till you get home to watch.

What we see is a mortar team firing their 120mm mortar at Anti-Coalition Forces that are (presumably) attacking their Combat Outpost. Since the idea is to suppress the incoming fire, they are laying down both High Explosive and White Phosphorus rounds on the enemy. The HE of course blows up real good, and while the WP may cause casualties, the primary effect is the dense white smoke makes it hard for the enemy to aim their weapons.

Note the professionalism of the crew. Just as soon as the fight is over, they start clearing up the pit, counting their ammo, cleaning their tube, and generally getting everything set for another round. Impressive.

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