I am in the process of building a couple of new uppers for my AR. One of them is going to be a 6X223 and the other I have yet to decide. It will be one of the following: .30HBR, 6.8 SPC or a 6.5 Grendel.
Has anyone here actually built a complete upper Assy. for an AR?
What I am planning is:
1) new bolt & carrier with a .223 & PPC sized bolt. This way I will be able to change the bolt itself in the carrier when changing uppers with diffrent case head sizes and the bolt will be matched to the barrel.
2) Adjustable gas block so I can adjust each barrel for optimum performance.
3) Flat top upper for the best ability for mounting optical sights.
4) Free float forward handguard with lower rail for mounting bi-pod as needed.
5) Medium to medium heavy 18 - 20" SS barrel & target crown, no break/flash hider as they actually hinder optimal accuracy.
About the only thing that I've done in the past with ARs is build up lowers and changed barrels in the uppers in the same caliber - 5.56/.223 and each time I changed the bolt in the carrier as each blot wears with the original barrel.
I am asking for opinions & ideas, What cha think?? Thanks