Before you bend it, lay a straight edge along the right side of the barrel and measure the gap between the barrel and the straight edge. Use number drills. When you get one that will just pass in the gap, measure it and write the number down. You can set up the barrel on a stiff bench and "V" blocks made of wood at the ends, and then use a big "C" clamp to introduce a bend into the barrel. When you've tried to bend it, remove it from the blocks and again, measure to see if you have bent it. Hopefully, you'll be able to pass a larger number drill, but again, write it down. Now shoot the gun to see if there is an improvement. If not, repeat, introducing more bend until the gun shoots where you are looking.
You said you removed the front sight...you cannot expect measurable results without at least a front sight. Make sure, when you attach your new front sight that it is in the centre of the tube. No point bending the barrel further than necessary.
If that system is going too slowly for you, put your "V" blocks on the floor and step on the barrel so that it deflects top the right. You'll be surprised how much pressure you can apply before you see any results...remember to measure so you can see if you're making headway.
When I needed to bend my Bess barrel, I did it at the range by removing the barrel from the stock, seizing the barrel by the muzzle, and whacking it against one of the upright supports for the Shooting shed...got some strange looks but no one asked me any questions. I think I had to whack it several times before I was happy with the results, but it did work and went from missing the mark to centre punching it. I won many smoothbore matches shooting that old TRS Bess, but in a weak moment, sold it to one of this site's subscribers...regrettably.
