I was given an Magpul STR stock a number of years ago by my wife as a birthday gift. I decided a while back that it needed to be rattle canned (Rustoleum). While I liked the camo job at first, I started to fall out of love with it. Fast forward to now, and I’ve been trying to get the paint off using a number of methods. I tried aircraft paint remover as a thread on here recommended. However, I didn’t realize that the thread was 9 years old, and since then Klean Strip removed the chemical in the paint remover that actually made it work well. So I tried soaking it in brake fluid for 18 hours. That didn’t work very well either. So, to those experienced with this, what are my other options? Would brake or carb cleaner work well for removing the paint but not hurting the polymer?

It’s a $75 stock - I’d just buy a new one. Or paint over the camo  color.

Try citristrip, and wash it off with pressure washer.

If it’s bonded that well then just scuff it up, wipe it clean with denatured alcohol and paint it the color you want.

Honestly, after looking online at a lot of guys having luck in the model kit community with using Isopropyl Alcohol on plastic with good results, I may give it a try.

ive used acetone with varying degrees of success.

Don't know about rustoleum.

I do know I've taken krylon camo paint off a carbine stock with carb cleaner and a toothbrush.  Spray, scrub to loosen it up, wipe off with a paper towel.  Repeat till it's clean of paint.  Then I wiped it with alcohol and a microfiber rag hoping to make sure I got all of the residue from the carb cleaner off.  Then I put a coat of nufinish car wax on it.  

It's been on another rifle so many years now I can't even tell you which carbine it was installed on now but none of them are shiny so the wax must have worn or just dulled.

Waxed with the ignorant idea/knowledge that the plastic needed some kind of protective layer on it after the carb cleaner, brushing and wiping down with alcohol.  These days I'd probably wipe it down with one of the plastic trim liquids intended for car trim.

Mineral spirits should strip it right off.

Soda blasting or EezOil

Citristrip is what you seek, indeed.  Works like a charm.

Another vote for Citri Strip. If you're just going to repaint it, just paint over it.

Citri-strip + a mild abrasive material (IE a brush of some sort). Expect certain areas to put up a fight and don't expect to get 100% of the paint off unless you want to commit hours to it.

I'm too lazy for that and either paint over it or get some off and call it a day.

I may give the Citri-strip a try. The 91% isopropyl alcohol didn’t work very well. Soaked 48 hours and scrubbed with a brush. While it did work better than the brake fluid, it still wasn’t anywhere near super effective.

Citristrip

And pressure washer

Goof off works great also citri stip. I did a lower I citristrip recently stripped the parts off it and let it sit overnight in Tupperware container so it don't dry up. Clean off with brake clean and plastic bristle brush