You should try a different bullet design. I have an RCS (C3 dehorned with night sights) and it will feed Winchester PDX1 bullets just like they were round nose. Some 1911's can be finicky about wide open hollow points as the front edge of the hollow point catches on the rim of the barrel throat. The PDX1 has a much more rounded profile which is why I chose that design for the RCS. The Hornady ammunition with the XTP bullet is about the same profile.
If you want it to "feed anything" - then either send it back to SIG with a box of bullets you want it to feed and they will rework the barrel and feed ramp, or as suggested, take it to a local smith who knows 1911's.
My suggestion? If you're wanting it as a carry gun, try several different bullet designs, find the one that works and use that ammunition. First in my book would be the PDX1 or the Hornady XTP as I've never had a problem with them feeding in 8 different 1911's. If you're loading your own ammunition, then I'd use the Hornady XTP bullet.
As a side note - when I got my RCS the first thing I did on day one was lube it up, take it to the range, and put 300 230gr, FMJ rounds through it. 1911's really do like to be "exercised" a bit when brand new. There are parts that need to seat and mate with each other even on $5000 guns - and the only way that happens is by shooting a well lubricated gun.
I usually take at least 4 magazines, load all of them shoot all them reload, repeat, etc. Getting the gun hot and running it a bit on the wet side is the best thing you can do for a 1911. I now have close to 750 rounds through my RCS in two weeks, and it is running like every other 1911 I have - flawlessly.
Last time I took it out was with 100 PDX1 bullets for proof of operation with my carry load - run 4 mags, reload repeat, rapid fire, double taps, etc. In about 1/2 hour I'd put all 100 through the gun with no malfunctions.
If you haven't shot the gun to 300-500 FMJ rounds, do that first before feeding it hollow points - then be selective about what you're using.
