To my knowledge they use it because of compatibility. [Wayne]
Logistical compatability is crucial in military decision making - hence sniper rifles chambered as 7.62mm rather than the tighter .308 Win. At the end of the day, if the specified sniper ammo has run out and you're not able to resupply, the rifle can still be fired with any old 7.62mm on hand.
The Holy Grail for military planners is the 'one-shot hit at 800 metres' so far as sniping goes in recent years. That's a huge step forward from WW2, Korea and the post-war period, where a head shot at 300M was regarded as very good and most WW2 German kit couldn't reliably achieve it. 7.62 / 155gn or 175gn is pushed at 800M - the USMC regard the M119LR as 'falling off a cliff' beyond that range.
In practice, the number of times that shots can be taken at a true 1,000yd or metres in combat theatres is very small, largely through blocked sight-lines. The Middle East is a likely exception to the rule given the scarce vegetation and greater likelihood of being able to shoot over long open spaces. Many of the past so-called 1,000yd shots in times before cheap rangefinders became available are reckoned to have involved rather short steps - a bit like many 500yd deer kills in the past! Snipers who want to stay alive will often pass up a very long shot too if they have moved out into the opposition's territory - what benefit is there in taking the shot, missing, and stirring up a hornet's nest of enemy activity when you've got to withdraw unseen unless you want an artillery or mortar strike brought down on your head. You can shoot the best cartridge in the world ballistically, but 1,000yd is a still long way when it's a single no-sighter shot. Afghanistan may be a bit different again as it's 'asymmetric warfare' - the other side hasn't usually got artillery and certainly hasn't got fighter-bombers to retaliate with - as a western army will nowadays once a sniper is detected.
Our (British Army and Royal Marines) snipers have almost entirely switched to their .338 Lapua Magnum Accuracy International rifles in Afghanistan to make their longer shots more effective. This is a far superior anti-personnel cartridge to .300 Win Mag as well as 7.62mm in this sort of terrain, especially when coupled to rangefinder use. The US military authorities are opposed to the use of .338LM on the basis of 'sound signature'. This says that you might as well put a flag out saying 'sniping specialist present' when you use such a cartridge. This was how US troops knew they had a proper NVA sniper shooting at them in Vietnam - specialist snipers used Mosin-Nagant M1891/30 rifles with the 7.62X54R cartridge, nuisance Viet-Cong 'snipers' had SKS and AK rifles firing the little 7.62X39mm M43, and the two had a quite different signature to those on the receiving end. As noted, it doesn't matter that much if at all in Afghanistan thanks to the other side's lack of heavy weaponry and total lack of air power.
To my mind, what is much more of an issue than specialist sniper kit is 'sharpshooting' at rifle squad or platoon level which has been woefully inadequate in western armies for decades. That is, the general inability to hit anything smaller than a barndoor with the issue 5.56mm rifle at anything beyond 200M. The old Soviet Red Army recognised this with literally thousands of SVD 'Dragunov' rifles issued to troopers who showed innate shooting skills, on the basis of a sniper rifle to every 8 or 10 riflemen, and this continues in the Russian and Eastern European armies. These guys can make reliable hits out to 500-600M and you don't need to expend thousands of .50 Cal machinegun rounds or fire a $50,000 Javelin missile to take out a single machinegun or mortar position if you can't get arty onto the target. The US has recognised the deficiency in recent years with its Squad Designated Marksmanship program and M110 KAC 7.62 SASS rifle. Our guys have resisted asccurate shooting skills for years and won't support civilian accuracy shooting on PC grounds and have paid the price for it - they've finally woken up and bought 440 (wow - all of 440!) L129A1 'Sharpshooter' rifles from the Lewis Machine Tool Co. in the USA, semi-auto 7.62mm semi-sniper rifles like the Dragunov and US M110 to fill the gap.
Laurie,
York, England