After all the feedback and suggestions, i spent a lot of time today with some rounds of 243 and the gun (ulp!), observing the cycling. I found if I loaded rounds all the way to the back, and, pushed the tip of the 4th round down a little so that it's butt is over the bolt face, there's no problem to strip and cycle it! And thereafter all rounds cycle. (Of course by now I've sprayed Balistol everywhere and wiped things clean.)
Now, if i loaded all the 4 rounds forward until the farthest they can go, the shoulder of the 4th round is very tight - no more give below it. It's butt is able to flop up/down in the back of the mag well. The butt of round 4 will sit below the bolt-face, and therefore it can't be stripped. I have to be careful to push the tip down, to lift the butt up. But then more often than not, the 3rd round gets stripped at the same time, jamming the action!
I went and stretched the spring good, loaded the rounds all the way to the back, and now the 4th round just sits flat - the bolt face catches it everytime. I can cycle the rounds through completely (albeit the last one seems to bind a bit before I can push the bolt home - but that's another issue i think!).
So with new spring that I've ordered installed eventually, I think this problem will be solved adequately.
Last edited by sirusa; December 15, 2009 at 06:08 AM.