Here's my sad attempt at a review. Bear with me as I'm no gunsmith and I may get some of the terms wrong. If so please do correct me.
When I saw the S&J Bobcat forend, I thought it was so darn cool I just had to buy it. After getting the forend and some other accessories it only made sense to buy a gun to mount them on, so I thought I'd give the cougar a try based on some positive initial reviews. The S&J forend WILL NOT work on the cougar unless you run a remington o-ring. The factory "donut" washer is way too thick and doesn't leave any threads for you to screw the mag cap/extension back onto the mag tube.
Speaking of mag extension, I cut my +2 extension down and capped the end so it only holds 5 shells.
I found this extension works very well for what it costs. Just make sure you keep it in place with a clamp or it will start to unthread itself as you shoot. In fact this $20 extension is (in my humble opinion) far superior to the factory remington +2 extension that came with my 870 tactical. I have had zero issues loading to full capacity on the cougar, while on the 870 tactical the spring and/or follower always seems to jam up and I cannot load the 6th round into the tube. I've tried with the factory and S&J No-jam follower but the results were the same. I can only load the tube to capacity maybe 1 out of 15 times. I'm thinking I'll toss the remington extension and run a DA one instead on my 870.
The ghost rings work well, but on my cougar rear site keeps loosening up after a couple dozen shots.
I've tightened the screws to the point of almost stripping the heads and they still come loose. I gave up and put loctite on everything. It's no longer adjustable but that sucker will stay put. If it still moves I'll TIG weld the damn thing in place.
Some people have asked if there's 1 or 2 ports in the barrel. It has 2.
I figured that with 2 large gas ports it should have no issues cycling target loads, but I figured wrong. Cycling on the cougar is a hit n miss, more so the latter. Quite often I would get a failure to extract, other times when the empty shell ejects the next round would get hung up and fails to go into battery. I'd have to pull the bolt to lock it back and hit the release to load the next round. When it does cycle properly it's pretty fun. Takes me back to when I first learned how to ride a bike. But then everytime I get a FTF it reminds me of the moment I fell off my bike and knocked out my front teeth on the curb.

I've read that a lot of feed issues has to do with the gun being dirty. I'm pretty meticulous with stripping down and cleaning my guns, but just to be sure I did a complete strip and cleaned it again before taking it to the range for more testing. I've done this 4 times now and the extraction issue has gone away but the feed issue still persists.
I suspected that the feed issue has to do with the sloppy "ramp" (if that's the term) that leads into the chamber.
You can sorta see how rough the "ramp" is (sorry for the poor pic). Everytime I had a feed issue the lower edge of the shell would get caught on the flat spot on the barrel. So I made the "ramp" more prominent and polished it in hopes that the shells will feed properly.
So far it seems to feed much smoother. I will have to do a range test before I can report back on whether this fixed the issue or not.
Given that my gun didn't like to cycle target loads I thought I'd try some 3" slugs. They cycled fine for a few rounds, and for a brief moment I felt like there was hope for this gun. That was short lived as the bolt locked up half open and was stuck in that position. Once again I'm left cursing at the gun as I pull out my tools to strip the gun down and diagnose the problem. No more sunshine and rainbows, my world is a sad sad place. If the damn gun had a face it would giving me a big s**t eating grin as it took delight in my misery. The issue with shooting 3" slugs is the recoil spring in the stock gets battered too much and the "wishbone" looking fork thingy (one of you guys have to correct me on that one cuz even I know that's not the right term) no longer stays in the "cup."
One of the prongs ends up popping out of place and gets caught between the "cup" and the tube causing the bolt to lock up in mid cycle.
I assumed that the recoil spring was just dirty so I took it out for a good wipe down and gave the tube a thorough scrubbing. With high hopes, I was off to the range for another test. Again the gun reminded me that the greater the hope, the greater the disappointment. Out comes the tools again...
I have tried various 2-3/4" slugs and buckshot with some success so now I just don't bother shooting anything 3" in this gun.
After stuffing the cougar to the back of my gun cabinet for the last 2 months I decided to take it out for a test run. This time I was only running 2-3/4" slugs as they seemed to be the only thing that cycled properly.....so I thought. Fired the first round and the bolt jammed again! This time when I removed the trigger group to fix the jam I found this:
At this point I've concluded beyond a reasonable doubt that this gun just hates me. I managed to wedge that bar back into place and it seems to be quite sturdy. If necessary I'll just TIG weld that sucker too, but with the trigger group installed it doesn't really have anywhere to go so it's not a huge issue.
I've read many favorable reviews on the cougar so I honestly believe that mine is just a lemon. I didn't expect a flawless gun for $400 new, and sometimes it's true that you get what you pay for. If you're fortunate enough to get a proper functioning one, then you get MORE than you pay for. Will I continue to buy Norinco/Dominion Arms products..... absolutely! Despite all my grief I don't consider my cougar a complete right off....yet. I think I can fix most of the issues and get the gun cycling properly. Personally I enjoy tinkering so I don't really mind having to troubleshoot and fix the issues I've had with this gun. The only thing is it can be annoying when it fails while I'm at the range trying shoot like a superstar. Little embarassing when you have to tell all the girls watching you that "I don't know what's going on, this usually doesn't happen" LOL. (I'm talking about the shotgun).
