[AZshooter]

The iron/rag procedure works for small dings & dents. If you need to work on the really big & deep dents that occurred from careless handling of "old junk" rifles thrown into a scrap bin to sell to US collectors, you need some serious steam.

I have an old pressure cooker that works great for dent removal. I simply fill it with water, put it on the fire with the pressure regulator left off the stem on the lid and wait for trhe pressure to build. Once a steady stream of steam blasts forth from the stem, I'm ready to commence steaming. It not only swells dents like no other method, but also helps minimize scratches, and work out excess cosmoline from the wood.

 

[AZshooter]

Where did I get my pressure cooker? Out from under the counter in the cabinet where all the pots & pans are stored

Actually, my wife had it, so it must be at least 16 years old.

Yard sales are a good source, since people dump them when the lid seal begins to leak under pressure. Since you're not using it under the pressure intended for cooking, but only to generate a directed column of steam, the seal is no big deal.

Otherwise, Target, Walmart & anyone selling pots & pans & kitchenware should have them.

I've actually cooked some stuff in the pressure cooker & it is pretty quick for rice dishes & casseroles.