Since the 1970’s investment cast steel receivers for commercial M1 carbines have been common, with satisfactory performance. My I-J has mostly cast parts; slide, bolt, hammer, trigger housing, in addition to the receiver. Cast steel alloys, whether 86XX or 41XX series, duplicate metallurgical properties of equivalent wrought steel. Just because a new commercial carbine has a milled receiver, doesn’t make it superior to a casting. In fact, if the receiver has not been forged from the billet before the machining, optimum physical propertied won’t be attained.
This being said, you can’t ignore the subsequent heat treatment, which provides the final strength properties. Unless the hardness range of parts, especially the receiver and bolt meet original USGI specs, it might be unsafe.
If you want to see a replica M1 carbine receiver, subject of this thread, see this website, a well known replica parts provider:
www.riverbankarmory.com/parts1.html . Scroll about 1/3 down the page.
Correct spelling is ROCK-OLA, photo looks more like ROCX-OLA, and note the rough machining on the lower right of the slide surface. That font is even close to original, but on the other hand these are not real Rock-Ola products from 70 years ago. Wouldn’t be surprised if these Rocx-Ola’s had a cast bolt, hammer, and trigger housing.
Retired metallurgist
