What size should I drill gas port to or does it matter?

[Keith1863]

Thanks to tp555 I now have a Daewoo DR200 upper barreled in 300 Whisper. My only question now is what size to drill the gas port in the barrel?

This thing has been SBR'd and will ultimately look like this:

http://www.gunbroker.com/Auction/ViewItem.asp?Item=123497181

I guess it could oversize it some and still be okay since the Woo has an adjustable gas system...that little plug under the front sight? Right?

Thanks,
Keith