Nah M4 has better control, less freeze, and spread. It's also got some pretty nice perks, M4 is great for sparring and pretty much anything if you know how to use it. Sten is a nice gun, but recently it doesn't seem as useful with the no spread, but don't get me wrong, I've seen people dominate with the Sten. it really depends on what your doing, but for your range I'll show what I think is best.

M4
^stats already shown

Sten

Pbp Auto Rifle
Damage-6
ROF-High
Spread-High
Auto- No (lol)
Clip-High
Freeze-Low
Summary-This gun isn't auto, surprisingly by the name. This gun rules in spar, all you need us the basics of dodging, perfect condition, and this gun rules. The massive spread and ROF makes a great deal, and even sports some low freeze.Great gun for the price. ($55,000)

FN P90
Damage-6
ROF-High
Auto-Yes
Clip-Medium (Fast Reload)
Freeze-Medium
Summary-I love this gun. It's fun to use, it's got a little bit of freeze, but has a sweet ROF and spread, feels very nice, highly recommended, and the suppressor is pretty fun to play with also. ($55,000)

AA12
Damage-7
ROF- Very high (this gun RULES)
Auto-Yes
Clip-High (It's like 32)
Freeze-High (When spamming you can't move, but it works out better than it seems)
Summary-Great! Nice for PK, I have pretty much all the good guns in the game, but ones things for sure, this gun rules for the price. Not even my pbp stacks like this extremely fast shotgun.($60,000)

Ab8
Damage-8
ROF-Medium-High
Auto-Yes
Clip-Medium
Freeze-Low
Summary-Okay, before you judge this slow expensive gun ($65,000), this gun can be good. Now, when auto this gun is super slow, when you use Tap fire ( Semi-Auto ) this gun is very very fast. Almost the opposite of what you think. Still, there are many guns that are better that don't require a neat "trick" to use.