I've got an Indian Creek .675 for my Mossberg 935. When I went to install it, it was a very tight fit just getting to the threads. I had to put a little choke grease on it just to get to the threads. But, once it got to the threads it went in just fine. Looking inside the barrel everything is flush with the barrel.
I tried this on a 835 too and had the same results with it being tight. I have used numerous extended aftermarket chokes for waterfowl for years and have never had one this tight. Most of the time they will drop right in to the threads.
I was wondering if anyone else had seen this or if it was something to be concerned with.
Thanks.