I have both Models of MVP the Predator and the Varmint.
I find (as far as accuracy is concerned) they prefer bullets between 40 and 55 grains.
They both have an affinity for the Hornady 50 grain ZMAX/VMAX line of bullets and tend to shoot them very well at just about any speed.
I have gotten good accuracy with Sierra 65 Spitzers as well but most bullets above 60 grains tended to not shoot as well as the Sierra's.
I have used them both for Coyote hunting and they perform well for me.
I haven't had any problems in several thousand rounds through each and find they are accurate and rugged enough for my purposes.
The only criticism I have is that the Predator model's length of pull is fairly short (I'm 6 feet tall).
I added length to the stock here of late by using a Hogue slip on but pad that lengthens it about an inch or so and that makes it a perfect fit for me.
Other than that there's been no negatives with mine and I think you will enjoy yours immensely.
I am of the belief that the action is a great deal stronger than a M-4 so it would be safe [ I hope & believe ] to shoot 5.56 X 45 rounds through this.
These rifles have 5.56 chambers per factory specs.