Of all the ARs, I have the highest accuracy with the M16. It is one of the lowest KDR guns I have, but I think that's the result of a few things. For starters, I just went through to complete all the attachments recently. Matching those up to perks and proficiencies takes a while.
But here's some combinations I found helpful with the M16.
On CQC maps, I found the Heartbeat Sensor helpful. Be careful: either Blind Eye or Assassin (I don't worry about those perks enough to know which it is) is immune to the HBS. Don't let that scare you though. Instead, use Steady Aim in Tier 3. for proficiency I used Kick. Don't bother to ADS if someone rounds a corner. Instead, hipfire and the M16 is pretty damm good.
On maps that were a mix of engagement situations, I ran either Steady Aim or Stalker in Tier 3. For me, on these kinds of maps I run into a lot of situations where I have to engage multiple opponents so extended mags was a big help. I ran Quickdraw, as well, because there's still times when you're not going to have time to reload. Of course, SoH is the Tier 1 perk to run. With extended mags I also found running the Attachment proficiency and using Rapid Fire was a big help.
On long range maps, the way to go was using the M16 with the HAMR scope. Yes, its a pain to switch to the RDS/Reflex site, but really, you're not likely to be pressed for time when you spawn on maps like Bakaara. But the HAMR became very helpful on long range shots. With this combination you can run breath and Marksman ... but you won't have the most kills in the match. You can still get a lot of kills, depends on how careful you are moving around the map.
Another good combination for the M16 is to run attachments with Silencer and Rapid Fire. Using that combination you have a lot more flexibility in your perks. In fact, with this combination I could run just about any perk arrangement I wanted.
Another good combination with the M16 is using it as a Recon class. Run Recon, Hardline, and SitRep. The key to this combination is to focus on painting targets, not a high kill count. As far as kills go, just be determined to stay alive. Doing that, you don't take the big risks you do under normal run & gun situations. Let a team mate lead the way and before he rounds corners, pop off tubes, toss 'nades or tactical 'nades, etc. Cover your teammate's rear approach (you'd be surprised how many flankers' day you can ruin!). If you don't already have Recon Pro doing this, it won't take you long to get Recon Pro.
Another attachment I found fun on the M16 was the shotgun attachment. Now this thing was tricky to figure out. Amazingly enough, I actually started getting Striker users to back out of games on Dome. Imagine that. SoH, any Tier 2 perk, and Steady Aim. Part of the trick here is that you don't have the range of normal shotguns ... but face to face, the shotgun attachment wins. That's just all their is to it - the shotgun wins. What I would do is lure the other player into areas where I'd have the advantage. Get them to chase you down a corridor where you can duck then pop out when he rounds the corner and doesn't see you. The shotgun is also perfect for flanking. I loved sneaking up on two or three guys camping and taking them out in three shots. Even with an SMG, usually by the time the first one is killed, the other two are turning and starting to open fire. With an M16 and shotgun attachment, you usually come out ahead.
The proficiency that I found the least helpful on the M16 was Focus. I just could not find a combination that could make it work.
And I'm going to tell you something. Once you get the feel for the M16, it is more accurate at long range than the Type 95. If you like semi-auto or burst fire guns, the M16 is the way to go on Bakaara and Village. It's a great gun on Interchange, too, but I like the MK14 on that map. If the other team is really good, switch from the MK14 to the M16. M16s burst fire is better than the power of the MK14.
Good luck!
but not something i would keep on it, I think once i have finished up all the attachment challenges i will stick with Ext Mags & Rapid Fire, 
