Has anyone run a .458 in full auto? how hard do you think it is on the gun? Recoil doesnt matter much as I relize what it would be like my concern is for my “Cheap” Colt RR M16.
no body?
There is always a chance that you could have a slightly mis-timed, or abusive action, just naturally inherent to your registered receiver. Meaning that even with 5.56, over time you may egg the holes on your lower receiver. Possible, though not really common.
This dynamic would be magnified with the 458 SOCOM in full auto.
You can certainly run 458 SOCOM in full auto, but I wouldn’t do it on a $10,000+ transferable registered receiver. The only people who I have seen do it were using 07/02 demo lowers/post samples.
Again, the risk may be very slight to your lower, but your lower is not just a run of the mill $115 Stag/CMT/Bushmaster/ArmaLite either.
If you can afford to shoot enough 458 on your registered lower to cause problems with the receiver, you can afford to buy another registered receiver 
458 is not cheap to shoot, even with handloads
Nobody ever said NFA was a cheap hooby
Ahat Shivan said. There is NO way I would ever run a 458 SOCOM (or any other big bore AR round) on my transferable M16 lower. Too much potential to FUBAR a very expensive lower than can never be replaced. Just not worth it. Now a post-sample or with a DIAS…that would be a different animal entirely.
Years ago shot about 30 rounds of .499 through a old LWRC gun. Lots of thump, good times, but hell I like 12 gauge slugs in a M1super 90.
Matt