Since I have an M4A1 I'm gonna comment about it.
Safety - you do NOT have to look at the weapon to move the safety. Opening the safety shouldn't take more than 0.2 seconds to semi. To auto may take a bit longer, but the default for the safety should be semi, since it's faster to reach and more effective in combat - which leads to the next issue:
Recoil - All M16 type weapons (M16A2 especially, but also M4A1 and M16A4) have incredibly low recoil, which makes full auto and rapid fire unrealistically effective in the game to ranges longer than what would be effective IRL.
Sound - Way too weak. All rifles in game need louder sound, but the M4A1 especially. This might be 1 of the reasons it's said to be too powerful with a suppressor.
Mag sound/anim - Some people would hit the bolt catch rather than pressing it, but some say it's better to click it with your thumb. Anyway, the bolt going forward should definately be much louder than inserting a magazine. Also just putting the magazine inside will never have it in all the way. You have to either push it hard from the bottom or tap it for it to sit all the way in.
Trijicon - I think you need to make your trijicon based on a specific model. I personally know the TA01 and TA31 (I think these are right). That way it'll be a realistic one, with a realistic view.
Stock: Why always fully retracted? You never fire with it fully retracted. Some people use its differnet positions for comfort - shorter means less collision when shouldered while longer means more stability and with iron/reflex sights some more accuracy (since the hole/dot looks smaller). For acog 4x it only matters for stability as you move the scope forward on the rail anyway when u shorten the stock so that you have correct eye relief (3.9 cm with trijicon acog 4x). If you don't want to make it 4-position, at least make it always at 1/2 length (usually used for CQB and by SF units) or at fully extracted (standard). I can't understand from the model what kind of stock it uses - the 1 seen in
www.ar15.com on the upper left corner, or the one seen in
http://www.isayeret.com/weapons/assault/m4/m4.htm (btw u can also see the m16a4 there to fix its model). The latter originally comes with the rifle, while the first one is designed to sit better in the shoulder when standing/crouching and holding the rifle higher - in those positions the stock usually doesn't fully sit in your shoulder, and that's where the longer butt of the stock helps stability. If u google M16 stocks u should be able to see details about each. Another use for the 4 positions is when using lvlII and lvlIIIa vests, as they put the stock further from your shoulder. When wearing a lvlII vest you'd either keep it the same or shorten it by 1/4, and when wearing a lvlIII vest you'd shorten it by 1/2.
The 4 positions work like that in case u didn't know:
Where 1 is fully retracted, 2 is 1/2 extended (first "click"), 3 is 3/4 extended (2nd "click) and 4 is fully extended.
Model (obviously less important, but still, graphics matter):
Flip up sights - Why blue?
Trijicon acog 4x - read above
Stock - I've never seen such a stock. The M4A1 comes with a stock like u can see on
http://www.isayeret.com/weapons/assault/m4/m4.htm and can be replaced with better stocks such as the one on the upper-left corner at
www.ar15.com. Also nobody ever fires with stock fully retracted.
Safety - when u open the safety u can see it for a fraction of a second, but it stays on safe...
