F front sight base should be fine for a carbine barrel.
Now when sighting in the rifle, you where moving the front sight in the opposite direction that you wanted to move the shot on the paper, correct.
Hence if you need to the move the shot up on the paper, you should have been moving the front sight in the direction of the arrow.
So this means if the rifle is shooting low, you are moving the front sight down in the base and the direction of the arrow.
If the rifle is shooting too high,the you move the front post upwards in the FSB, or the opposite direction of the arrow.
Hence you are asking for a taller FSP (which they make and are .040" taller in lenght), but you stated that you have the front sight already threaded all the way down in the FSB (buried), and would in fact need a shorter front sight if the front sight is all the way cranked down, and you still needed it lower yet in the FSB.
Also, lets make sure that the rear sight is set correctly to start zeroing the rifle at 100 yards (read you try to sight the rifle in shorter than this with the dial set to 3/8 with the large aperture, and it going to be shooting low to start with.
When you set the dial to 3/8, you can put an allen wrench in the top dial part of the wheel set screw through the hole just in front of the aperture, loose the allen screw (#15), and then twist the lower portion of the dial until it bottoms the housing out, click it back up about 3 clicks, and lock the top dial back on 3/8 to the lower wheel part. This should get you in the hunt for a 100 yard zero as you screw the front sight back up to zero out the rifle.
If the rifle is still shooting low at 100 yards with the FSP screwed all the way in the base, then re-adjust the rear sight up a click or two more when it's set to 3/8.