Integrity of investment casting??

I am not a gunsmith, or even a handy tool guy. SO, my question is borne out of a real lack of understanding.

I have purchased an Essential Arms AR-15 whose "lower", as I understand it, that is the action, is made by investment casting. Now, I suspect that this is not going to be as strong as something milled out of a solid block of steel, but just how strong is it?

I am not sure how investment casting differs from any other kind of cast metal.

Are there any special considerations or precautions I should take when firing this weapon? I am hoping I did not pick up the "Corvair" of AR's!

It is a beautiful looking gun in an original (before the '68 ban) pre-ban configuration. It looks excatly like the rifle I trained on in the 70's when I was in the USAF. I do notice that it likes to be well lubed when firing and is more finicky than my AK. Also, it is MUCH more accurate and a bit lighter.

Essential Arms is not around anymore, but I believe that one of the other purveyors of AR-15 parts bought their tooling and produces lowers on it. I don't believe that they ever produced uppers or complete guns. Cosmetically, they differ in the shape of the fence around the mag catch. I cannot speak to the quality (or lack) of same with this brand as I don't/haven't owned/shot one.
Investment casting is like any other process. It can be done well or poorly. It can be the appropriate choice for a given product or the wrong choice.
Several of the AR makers do or have used investment casting over the years with no real ill effects. All in the proper machining and fitting. Ruger manufactures most of their guns with this process and they are renowned for strength if not their cosmetic appeal. They do this in steel, stainless steel, and aluminum.
I would expect no issues with your lower related to the casting process.

Thanks BBBBill.... (hope I got the B's right!) I had heard that EA was back in business, but I have no hard evidence on that! YOu are right, mine is a parts gun - it has all uppers courtesy US Army!

The number of receivers that are made using investment casting is far longer than the ones produced by other methods. All stainless steel handgun made are investment castings. The first being the model 60 S&W. The idea of the need for a stainless handgun was sold to the public before the first one was made. Kind of a great idea, you create a need in the public's mind before the product, stainless really lends itself to investment casting. Anytime you see the magic words 17-4PH you can just about take it to the bank you are dealing with a vestment casting (with exceptions). Investment casting is great for a number of reasons, not the least of which is reducing the cost of manufacturing the item. When ever some one tells you that a machined part is stronger than investment casting you know that the person telling you this has no or vary limited knowledge of metallurgy and machine shop practices.