Can anybody tell me what it is and how does it increase a guns range?

some of the newer 105mm computer designed shells have much greater lethality, putting them nearer to some 155mm performance. Have you seen the South African LEO 105, that can fire these newer, more lethal shells out to 30km? Gotta love Jane's, but damn! It breaks the piggybank to keep a subscription going!

Aussie check out this site. I think it will answer you questions. http://www.globalsecurity.org/military/systems/munitions/rap.htm

Doggtag: I've heard about those new 105mm shells. They sound pretty impressive. It seems there are a few new options coming around for 105s that the Brits might want to look into. In addition to the Leo, there was an article on the Defense Daily website a few weeks back that talked about a new 105mm gun being developed by United Defense that's suppose to be pretty light and fire out to 30 klicks using M232 MACS charges.

sandbagger, that gun borrows considerably from the SA LEO 105, under a joint memorandum with UDLP (Jane's Defense Weekly). I have seen a prototype turret mounting the weapon on the LAV(ideally, Stryker) 8x8 hull (also in JDW). It is also a contender for the US FCS program if the 155mm concept bellies up. With such improved ammunition, it may be in danger of doing so. Plus, there is an entire tried-and-true family of 105mm ammunition to use also. And the long 52 caliber barrel of the LEO would make it effective to use as an antitank gun with direct fire APFSDS, if necessary. Assuming the system would be incorporating the liquid propellant/laser ignotion system, these could all be utilized instead of full-cased ammunition. Tell the Brits to bring back the Abbots, boys!

"Gotta love Jane's, but damn! It breaks the piggybank to keep a subscription going" I'm lucky in that my university library has a copy on the shelves every week. You need to find a library that does the same!

I didn't realise that base-bleed rounds were just RAP's. Why are they always refered to as a different type of ammo?

A base bleed round has a slow-burning device in the tail to improve the airflow efficiency around the tail, reducing drag and giving a slight range enhancement. But a RAP , I believe, has a bit more "kick" in the form of a small, low-impulse rocket motor to get it up a bit higher in the atmosphere, giving a bit more range (normally at the expense of some accuracy)than just a base bleed element.. Can any artillery people add anything on this? ...

....I'd just as soon have it for my own library to reference, Aussiegunner ...

So does base-bleed come at the expense of bomb size, compared to normal rounds? Does it have a bigger bomb than an RAP?