Hi
Don't own one, but here is some info on their manufacture:
Charles Daly (CD) subcontracts 1911 pistol manufacture out to Armscor.
So does Twin Pines, which owns the Rock island Armory (RIA) name.
Armscor also now handles marketing and distribution of RIA in the United States and other countries: Twin Pines' earlier arrangements with certain US distributors went sour --the distributors wanting to jack up RIA prices, and Twin Pines firmly standing by the concept of keeping good 1911's affordable to the working person.. a concept they adopted from Armscor and its GI series.
Armscor parts are investment-cast 4140 steel, but done properly --the density is still not up there with forged but I've yet to hear of a real-owner complaint of practical weakness in the metal. Usually it's a matter of needing a break-in, though on older pistols the workmanship/finish is not as good ("--pistol works fine, but there's roughness in places"). Armscor's been aggressive in boosting quality over the past several years, and the postive reputation of RIA's is a result of that, but there's still some old (Armscor GI) stock floating around the US market, tainting the reputation of its own GI line of 1911's. I would think those interested in Armscor GI 1911 pistols should ensure their purchase is of fairly recent manufacture, and NIB, to get the current good quality.
Armscor naturally builds its own pistols start to finish.
The RIA's are assembled from Armscor-produced parts by Twin Pines here in the Philippines and over there in Nevada (by Armscor Precision). I would imagine Charles Daly also does their own assembly of Armscor-built parts.
There would thus be greater chance of difference quality wise, between CD and Armscor, than between Armscor and RIA.
One difference between Armscor and RIA is that Armscor makes its own sights and mags, while Twin Pines' RIA now makes use of US-brand sights and magazines.
I'm pretty sure the house brand gets extra TLC at Armscor's plant and forge in Philippines. The Armscor GI series has been around for ages and has always been intended as an affordable, working-man's weapon. I have to agree that when ii comes to workmanship, the Armscor GI 1911 seems to have a slight edge over the RIA (I've handled lots of such pieces, and sat in on field-strips at the range). RIA's have better (US-made) mags though, and if you're buying Armscor it's for now a good idea to factor in the possible expense of replacement mags.
hth,
horge
PS:
I wouldn't buy a 1911 for defense, as I'm too small/weak to use it.
BUT I am definitely going to own a 1911,
on principle, and choosing between an Armscor GI 1911 and a RIA is driving me batty
PROC-built Norincos are easily obtainable here in the Philippines and have this reputation for hard metal, but the rough workmanship I've seen in the shop units I've looked over turns me off. The Springfield Armory Mil-Specs look very good, but are still a tad too pricey for me. JMO, YMMV