For my new build, I am looking for an upper receiver to mate with a DD chf barrel. This takes me to the following:
After doing research on this and numerous other forums, i am wondering if somewhere something is being overlooked: A lot is made of lower receivers. Considering most are initially made (forged) by the same manufacturers, and the finishing is done by the respective builders, what separates them is tolerances and some details in final machining and finish.
Active use creates relatively little stress on the lower, other than on stock and upper retainer pins, so I am wondering why the upper receiver, which in comparison is handling exponentially greater loads of stress and pressures is (apparently) getting so little attention.
One reason I can think of is perhaps a lower is easier to assemble by the average consumer, whereas an upper may be a little more challenging? So it’s marketing driven?
Which brings me to the question: Am I seeing this right? Do the same rules apply to the upper receivers? Meaning: are they also forged by a small number of manufacturers, is there a difference between these manufacturers, or again does it boil down to the final machining tolerances etc.
I really don’t think it’s an issue of who makes “The Best”. Perhaps more realistically - who make the good stuff, what would be a worthy upper for this barrel, so at the end I can walk away with the most reliable, accurate rifle as allowed by the sum of this equation.
Thanks!
ps - I am impressed by the wealth of objective honest info on this forum, and the relative lack of back and forth bitching. Good stuff!
Most people, myself included, consider the lower to be a low stress part. Upper and lower forgings are made by only a handful of manufacturers. If you do a search there’s a thread somewhere about which markings correspond to the different makers. You can even buy raw forgings and machine them yourself. The final dimensions are determined by the machine shop doing the work and the specs submitted by the retailer. For the most part, any lower is fine. I think DD does all their machining in-house so their lowers are a bit more expensive.
However, not all lower (or upper) receivers sold by various mfgrs are the same, even if they were machined by the same supplier. Different rifle mfgrs have different QC standards. One rifle mfgr may have much more rigid standards for machining tolerances (and cosmetics) than another for the machined parts they’re getting. Naturally, if the first rifle mfgr is throwing more parts away, than the cheaper rifle mfgr, his rifles are going to be more expensive, but the parts are going to be more accurate.