Colt magazines and their equivalents (i.e. military surplus magazines) will be interchangeable in any mil-spec 1911 or 1911A1.

That covers a broad range of pistols and magazines. However; this day and time, there are so many new manufacturers and custom suppliers that it is anybody's guess what will interchange. I would hope that an inquiry to the specific maker would result in a straight answer as to whether a standard Colt magazine will work.

As for competitive disciplines using the 1911 platform, I have no information. All my shooting with those pistols has been informal plinking. I used to be a fairly good shot, but lack of practice in recent years has left me lacking. At age 71 I am not as strong as I was at 40!

Curl