Recoil in reality

Any light machine gun (MG using assault rifle bullets, such as 5.56) and medium machine gun (rifle cal., such as 7.62) have no upwards recoil while prone. You can check this out on any youtube video with SAW light machine gun for example.

Usage of LMG in reality

Light machine guns are (despite popular belief) supposed to be used at medium and long range. Many medium MGs have ability to shoot up to 2,000 meters, LMGs up to 1,000 meters. In fact US weapons guide specifically says machine gunner should target distant targets. Its quite logic too, because close targets can be deal with by ordinary soldiers. So argument above that LMG shouldnt be used at 800 meters is totaly wrong.

Conclusion

• LMG have no upwards recoil while prone in reality.
• LMG are supposed to be used at long range, MG is not short range weapon! Its not shotgun.