Basically, they made the FR-8 from old Mausers they had around.  They built them up with the sights, flash suppressor, and bayonet mount (the purpose for the tube) of the CETME, so that they could train on a cheap bolt gun that was set up more or less the same as the semi-auto CETME.

The only reason for the tube on the bottom is to support the rear of the bayonet.

-Troy

Quoted: I am still trying to figure out how to adjust the sights a few people tried to tell me how in writing but I just dont under it yet. Do I have to loosen that screw in front of the sight in oreder to adjust elevation. Six

Yes, but first clean thoroughly both the screw on the front of the sight housing, and the front sight post itself.  You want to especially clean out the notches in the front sight post with solvent and compressed air.  Get out as much as you can.  Next, apply the best penetrating oil you can find to screw and front sight post.  Leave rifle in level position, and let soak for a few days.
Reason for this is that both screw and post have such FINE threads, and they corrode easily.
Adjustment:  Loosen front screw.  Use CORRECT screwdriver!  Using selected NATO-spec ammo, fire for group at 100m.  Rear sight in open notch 100m position.  Adjust initial elevation AND windage using front sight post.  It is OFFSET for windage adj.  Once you have initial elevation a little high, and windage right on, you can snug up front screw.  Rear peep is 100m notch, and 200m, 300m, 400m peep apertures, depending on heights.  E-mail if you have Q's.
P.S. The sight tool linked above would be handy.

OK, Sixgun.  You will need to adjust the FRONT sight to set your windage.  Looking down on it, you will see that the conical front sight post is off center with respect to its base, the threaded part.  Following the directions above, adjust your windage by turning the post down slightly (probably no more than 1/4 turn, and lock it.  The reason for adjusting down is to raise the point of impact slightly (remember, the FR-8 sight is calibrated in meters which are longer than yards) whilst correcting the windage error.  Correctly sighted-in, with its metric-calibrated sights, the FR-8 will shoot slightly high of point of aim at 100 yds, and ideally right on at 100m.  The difference will be very slight.
Restated: your goal is to turn the front sight post however much it takes to get the windage right on and the elevation slightly high at 100 yds.  Hope this helps.