gears of war

i abandoned the original gears of war ages ago at the bit where you get wheels and have to switch between driving and blastin the kryll (pitch black much? lol) with the uv. anyway thought i'd give it another bash now i got a wee hd telly setup in my room. managed to get past. i've got as far as the conservatory nice idea for an area. oh great a berserker i might be stuck for a while again

okay i've got abit further on in this.
i'm currently stuck on the train. theres this reaper or whatever you call him and he's got these kryll swarming around him but no matter what i do i get killed. i take it the idea is to get to the machine gun post behind him and let rip

Just noticed yer post here dude, you are in fact on the last boss! If you've still no done this I can give some advice:

First off; the machine gun turret is a red herring, you just get munched by the bats. The basic tactic here is stick to the light spots, shoot until he gets close then leg it to the other end - rinse -repeat.
Try for head shots with yar rifle (and try get the boosted quick-reloads), as I recall you need to blow away the bats that shield him first which can be done with a grenade or the torque bow.

Edit:
I just looked on gamefaqs there and there's apparently a glitch where you can quickly nip back out the fight at the start:

There is a glitch where you can re-enter the ammo room
during the battle with RAAM. All you have to do is open one of the two doors
and then run over to the other door really quick and open it before the
cutscene starts to play. You will hear the door open as the screen turns black
which will leave that second door open during the battle.