Invasion 
Since I'm fairly new, I don't know all of your playstyles yet, other then the awesome fellas i got to play with in past few days, but if youre a hardcore sniper who likes to take it to the closer to the enemy or if youre looking for a little more punch than just a simple shotgun let me present to you the M417.
Now theres a few advantages in using this rifle and a very few disadvantages when used properly:
(my recommended accessories would be foregrip/kobra or red dot/laser/squad Ammo perk
PROS:
1. Doesn't take up much more screen than any regular assault rifle giving you more field of view
2. With Foregrip attached there's little to no recoil
3. Damage in no vital body parts is about 33%-50% and vital parts over 75% with headshots being 100% guaranteed.
4. If used with squad ammo you will have approx 180 bullets at your disposal which i have had yet to run out even on longest kill streaks (20+)
5. There's practically no horizontal after recoil effects down your sights which means most of your 2-shots or 3-shots will finish of the enemy straight at their head if aimed at upper chest with most bullet-hit area.
6. Has a phenomenal bullet reload speed which makes shooting from the hip (no-scope) much more lethal than any semi-automatic shotgun, plus the lazer will take care of your aiming issues up close.
7. Much faster reload than any shotgun period if used for close quarters battles.
8. Since you're playing recon you will always have a portable UAV with you to engage all your close range targets before they even realized you're in the area and with that much punch from the rifle a surprise jump on your enemies will be beyond lethal.
9. Last but not least - strongest semi-automatic sniper rifle currently in game!
CONS:
1. Requires the player to have a fast tapping finger - no spray an pray game play
2. If you're fairly new to FPS and your accuracy reaction times are slow, i would start with assault rifles instead, this rifle is very unforgiving while engaging without proper target acquisition
3. If you love 12X scopes on your rifles while equipped on m417 its absolutely useless and take days to get used to (i hope its a bug).
Not to repeat myself, but I wanted to say again the punch for the bullet is very outstanding. Rifle comes with 21 rounds per magazine and just a few days ago in Grand Bazaar I have sneaked behind the enemy lines and with just one clip within 7-8 seconds i had 7 enemies down bunched up in one corridor while using just one clip from M417 and one clip from my pistol (Tactical MP443 at that time). By the time I was done and stood there with my knife out ready to stab anything what moved after this enraging moment I realized bodies were already cold to sink my teeth in
