Need some grip help

I purchased a Wilson Combat ADP. I know many are asking, why? Well one I kinda like the gun. Small enough for cc and packs a heavier punch than my
.380.

Problem I had at the range yesterday was hitting the target way left. I am convinced the reason is I had to really grasp the gun to keep it from turning in my hand. The polymer grip is way too slick.

Today I stopped by the local shop and bought a Hogue Handall, slip on rubber grip.

Big improvement in shooting, matter of fact, I was overly pleased with the performance. The rubber grip does not fit tight enough and had the tendency to slip, so about every 3rd - 4th mag, I had readjust the grip.

That said, is there any product on the market that I can use to bulk up the grip a bit?

Thanks.

Those come in two sizes IIRC. Get the smaller one and have another go. Otherwise, try a bicycle inner tube. Cut it to the size you want and try as many times as you have tube.

You can always try cutting some grip tape (skateboard stuff) and applying it to the sides, front strap, and back strap. Not necessarily the prettiest solution but certainly economical and usually effective. It won't add too much width though. You might want to look into AGrips. No personal experience but they seem to add some bulk.