Thanks for all the help offered and suggestions.
I'm using the .490 balls as the .495 dont fit at all, I"m allready using a thin commercial patch made locally.
I"m thinking my homecast roundballs can maybe be the problem since they have a higher tin content, I ordered 2 boxes of pure leadballs last night and will test them next time I visit the range.
Hopefully everything will improve then

Be sure to post the results. And try some Hornady 240 grain XTP's with a sabot.

I thought about sabots but they are expensive, to give you an idea the US$ vs ZAR Rand are 1:8. They cost around R250 for the Hornady's, 20 per pack.
Another thing, my rifle is a frontloader(no breechplug to be removed) and it has been reported that the barrel fouls easily with the plastic from the sabots. It scares me a bit to try them.
I found a source with felt wads, now to organise a lift for them. From what I understand they can solve my problem.

Thanks anyhow for all the advice, I really appreciate it.