@Gessler @Johny_Baba its a proven fact that sight radius and accuracy are directly proportional to each other. If its the case why almost all the rifles of present generation doesnt have front sight posted at the barrel tip instead of either over the gastube (Insas, Ak-15/Galil) or at the end of the hand guard (M416).Whats the negative side of putting the front sight at barrel tip just like VZs or AkMs
This question requires historic perspective to answer, and I'm not Ian McCollum of Forgotten Weapons.
From what I think -
Though its true that longer sight radius helps accuracy with irons once you are dialed in, its easier to 'acquire' the sightline (line up the sights) with a shorter radius. So its a balance between accuracy & speed of use. And given the limitations of intermediary cartridges adopted from 60s onwards, long-range marksmanship-level accuracy was never expected from the iron sights, world had already moved to optics for marksmanship back in WW2 and by 60s, even more so.
Since 90s, optics are becoming standard place for all infantry rifles, so iron sights are simply nothing but a back-up option in case of emergency.
Some of the design limitations of having a front sight post at the very front is likely to entail how likely it would be to snag on something (serious problem with AK sight btw, more so than any other front sight). Performance-wise, its better to have the least amount of weight resting on the barrel for best accuracy (barrel should be allowed to move freely under force of recoil viz. barrel harmonics or the idea behind free-float handguards).
Just some stuff I could think of off the back of my mind.