It would seem that the easiest way to go would be to neck-up the 5.56 case to some larger size, e.g., the 6.5mm MPC comes to mind. This would allow continued use of magazines, assuming OAL of the round could be maintained, and all parts of the existing rifles, except the barrel and parts of the bolt assembly. The firearms designers can comment on mass-of-bolt problems with heavier, slightly slower projectiles. The same case will allow identical magazine capacities with slightly increased weight due to the increased bullet weight.
As someone who has used older military rifles, I find that firing the M16 was much more pleasant and much easier. The report is much reduced and recoil is about non-existant. Full auto was reasonably controllable and the rifle was a feather relative to a BAR [about 20 pounds, loaded]. Of course, the BAR has a much greater effective range and even brick walls will succumb to a 20 rd magazine, but a compromise between the power and ballistics of the .30-06/.308 and the 5.56 would be a 6.5 to 7mm.
Looking back even further, the effectiveness of the military 7mm and 6.5 rounds is well known from two world wars.
Caseless ammunition is a questionable fix for something that isn't broken and will require much more development.
I find that the bullpup design would seem to have little advantage in most situations. I have fired the civilian version of the Steyr and found that an extended magazine was awkward when shooting from the prone position.
As someone who has used older military rifles, I find that firing the M16 was much more pleasant and much easier. The report is much reduced and recoil is about non-existant. Full auto was reasonably controllable and the rifle was a feather relative to a BAR [about 20 pounds, loaded]. Of course, the BAR has a much greater effective range and even brick walls will succumb to a 20 rd magazine, but a compromise between the power and ballistics of the .30-06/.308 and the 5.56 would be a 6.5 to 7mm.
Looking back even further, the effectiveness of the military 7mm and 6.5 rounds is well known from two world wars.
Caseless ammunition is a questionable fix for something that isn't broken and will require much more development.
I find that the bullpup design would seem to have little advantage in most situations. I have fired the civilian version of the Steyr and found that an extended magazine was awkward when shooting from the prone position.
