Twist-lock nubbin to small?

Last weekend while I was at the field I noticed that the field paint was so small that it was actually double feeding past my plastic barrel nubbin on my large bore mag twist-lock barrels that are .689-.690. I switched up to a stock RT barrel, that had twin barrel nubbins instead of one like the aftermarket barrels, and it didn't happen as much.

Is there a way to make a plastic nubbin larger? I thought about adding a drop of crazy glue to the nubbin tip, letting it dry, then sanding it down to the appropriate size. What do you think?

Get yourself some black tape. And apply it very TIGHT around the barrel where the nubbins protrude through the breach of the barrel. This will only work for the plastic type nubbins. If you have the wire type then you'll need to make your own with a thin paper clip

If you look at the back of the nubbin, you will see a tiny knob. Pushing on that knob pushes the nubbin farther into the barrel. By wrapping tape around the barrel over that part of the nubbin, you can make the nubbin push farther into the barrel so that it will work better for smaller paint.