Iron sight distance: carbine vs. classic AR?

[Ignition Override]

My rifle experience 'pretty much' began in '07, age 52.
Have done limited shooting with my Garand, but more with Enfield #4/#5 and mostly the SKS. All shooting is with original sights, and the 'family' was acquired Only because of their original, military character.

With a tiny bit of time on ARs, my impression is that the carbine M4s always have a clearly shorter sight distance than the classic AR-15 .223 Colt, which my friend owns (keeps in my house).

Considering Only factory iron sights, is there a clear relationship between sight distance and carbine vs. original length?
The standard length seems to have the sight post near the end of the barrel-but never on the carbines.

 

[Mobuck]

rifle barrel is 4" longer than carbine to begin with

 

[Ignition Override]

True.
And so the sight distance is almost always proportionate to the barrel length (?).

 

[Dragline45]

It depends, if you have a fixed front sight base, your front sight distance will only be as long as your gas system. Carbine gas systems are the shortest, hence shortest sight distance, than mid length, and rifle length which will have the furthest front sight distance.

If you don't have a fixed front sight and have a low profile gas block, you can add a free float rail/forend that can be just about any length you want it. So a 16" rifle with a full length forend can have the front sight distance greater than a 20" fixed front sight base even though the barrel is shorter.

 

[DMK]

If you want to shoot with iron sights exclusively, you really can't go wrong with the "A2" pattern AR.

A lot of guys complain about weight and assume that these all have heavy barrels, but actually a true A2 pattern rifle should have the barrel milled down under the handguard.

Another option is the A1 pattern gun, but these have a simpler the rear sight and a 1/12 twist barrel. Though they are lighter and better balanced IMO.

 

[DMK]

If you must have a 16" carbine, one option is a Midlength gas system. That will give you a slightly longer sight radius vs a CAR/M4.

 

[Model12Win]

Get a red dot optic (RDO/"rido").

Better target acquire, more lead on target, more fast.

Barrel length won't matter.

 

[Ignition Override]

Interesting. Thanks for your time, especially for the links.