It does have M4 feed ramps, mil-spec trigger, commercial buffer tube. Using 55g out of the Mod 2 Sport 16 in, I was pulling 2,789 with the 62 green tip. I hit 3,150 but was constant at 2,980 and 3,050. I have put well over 900 rds to a thousand, never jammed. Hits 300 yd to 500 yds easy with the right ammo. The Delton Sport Mod 2 is a 1:9 twist, so use 55g for up to 250 yds, 62g or 67g for anything over 300 yds. Now u can switch your barrel to a 1:7 twist, run what the military runs, then you should be good for all sorts of grains.
I love my Delton Sport Mod 2. It never let me down. Even when it's dirty, it shoots straight, never fails or jams, hasn't rusted, no major problems, easy to upgrade. The only thing I recommend is getting a mil-spec buffer system and an H3 buffer set, along with an FRT and, of course, a scope, red dot, magnifier, hologram, IR scope, NV scope, or just old-school iron sights lol, your choice. If you get the FRT and the H3 buffer system, get an adjustable gas system. Otherwise you'll have malfunctions because you won't have enough gas to eject the spent cartridge and push back the bolt.