08-30-2014, 08:29 AM
Forged aluminum receivers are stronger due to the fact that they are forged, but the mil-spec dimensions are within a range of tolerance that sometimes ends up with loosely fitted parts. One would need to sit and try many different uppers to find one that is tight to the lower, a matter of trial and error.
Billet is not as strong as forged, but manufacturers can build them with tighter tolerances resulting in a precision fit of upper to lower.
If I was building a competition long range AR, I would choose a matched billet set.
For general use, I would choose forged, due mainly to lower cost.
And , like my DCM rifle, forged lowers and uppers can be tightened up just fine using epoxy bedding and shims, making them as "precise" as billet.
In your case, since you have a billet lower, I would get a billet upper.
There is no guarantee that they will mate up perfectly, but you have better odds of a tight fit, and might be able to send your lower to them and have them find a good match.
Billet is not as strong as forged, but manufacturers can build them with tighter tolerances resulting in a precision fit of upper to lower.
If I was building a competition long range AR, I would choose a matched billet set.
For general use, I would choose forged, due mainly to lower cost.
And , like my DCM rifle, forged lowers and uppers can be tightened up just fine using epoxy bedding and shims, making them as "precise" as billet.
In your case, since you have a billet lower, I would get a billet upper.
There is no guarantee that they will mate up perfectly, but you have better odds of a tight fit, and might be able to send your lower to them and have them find a good match.