I had a TM 1911 last year with nigh on the exact specs you described above and mine had the same issue (I think the most I got was 10 shots with a warm mag) sent it away to get it serviced + fixed and was told there was nothing wrong with it. Gave it to another guy who told me the same thing so I swapped it for a P90. I tried mine different mags, replaced the BBU and spring set but nothing helped. Only conclusion I could draw was all these pretty guns you see in the picture threads with all these nice upgrades belong to collectors and not your average skirmisher. Sorry I can't actually help you but at least you know your'e not alone
Also the jamming problem sounds alot like the problem I just had with my stock MEU. As mentioned above it turned out to be the hammer just lightly catching on BBU where it had happened alot it wore a little lip on on both the BBU and hammer so I filed the little lips down ever so slightly and now it cycles everytime.