The BiL gift finally came together last weekend when Oleg Volk gave me some of his stock of ,458 ammo (which apparently there is NONE in Middle TN) and I ran a function test on the animal. The final configuration was a Palmetto State lower and a Bear Creek Arsenal upper which was given a many fine review for what it cost. The bitch has been magazines, but mostly my stubbornness of trying to use Magpuls with dedicated followers. I was too trusty and ordered two from an online retailer who promised they would fit but didn’t without lot of file work. I ended up using GI mags but have troubles feeding reliably. I am gonna tweak the followers some more or simply eat the expense and buy a couple of truly dedicated (and expensive) 458 mags.
OK, long story short: I took the rifle and the ammo to Oleg’s range and shot several rounds testing the gun which went bang but with feeding issues from the mags. I segregated the one mag giving me crap and used the other one in controlled and aimed shooting some 60 yards to a steel silhouette. First shot rang and shook the target like Vulcan himself used his hammer on it. The second one simply took down the whole set up in spectacular way. With a mixture of elation and horror, I realized I frigging killed that steel apparently by shaking the spikes out of its base halfway out with the first shot and collapsed it with the second. I had a devil of the time trying to stand and keep the darn thing back up.
As for the recoil, as expected was bigger than with 5.56, but very controllable and not uncomfortable.
Later I checked the ballistics of the round and I am impressed: 300 grain Hornady hollow point at some 1,850 fps will most definitely make for a memorable and final impression on its target. But at over $2.60 per round of the good stuff, it makes for a non-plinking long gun.
Now I have the hankering of having my own .458 SOCOM, but I will hold till I get all the necessary stuff for reloading it. Plus, I am not experienced on bottleneck reloading and I want to make sure I know what I am doing. But before all that, I owe the missus an AR-base 9mm pistol and I don’t want her mad at me. And I am eyeing a 7-inch upper that weighs next to nothing and I want to see which part of my body I will need to trade for it.
I recall the words of Stephen Hunter about sticking an AR in the safe, lock it and before you realize it, it somehow managed to multiply.
Regular AR Pmags hold 10 rounds of .458. I was told they work reliably.. Some AR 9mm pistols may require tweaking to get them running correctly.
They MAY work.
You take a double stack magazine designed around a bottlenecked round and use it to load a single stack of straight (.450 Bushmaster) or nearly straight (.458 Socom) rounds at roughly a third of the original the capacity. You need a different magazine geometry for a reliable function.
There are at least two companies that produce dedicated magazines for those rounds – granted, they are more expensive than a PMAG but they WILL feed, not MAY.
I tried both PMags and GI standard mags and both eventually produced malfunctions. I will have to go with dedicated mags.
Admittedly I’m a novice, but I’m confused by the comment about stacking. I would think the stacking of the rounds in the magazine is controlled by the largest diameter, so the body diameter of a bottleneck cartridge, not the neck diameter. The body diameter of .458 is the same as that of .223, that’s part of the point, right? So wouldn’t it stack the same way? At least if the magazine cross-section is rectangular, not tapered.
“The body diameter of .458 is the same as that of .223, that’s part of the point, right?”
No, not even close. The case head is the same as a .308 and the body just behind the shoulder is .535 inch.
The feeding problems you are having are because of the bullet you are using. I finally settled on the Hornady 325 gn FTX. It was designed for 45-70 rifles with tube magazines. Has a pointed plastic tip and feeds from un-modified AR magazines every single time. I load mine right at 1900 fps with IMR-4064, no pressure signs, and I have one lot of brass that is on the 11th reloading cycle.
I hear ya and understand your need for the round. I decided on the similar .450 Bushmaster but unfortunately the delivery of my rifle with a 9″ barrel got delayed.
What is not to like about the energy of a .45/70 in a compact semi-automatic rifle?
I’m thinking of .500 Beowulf simply as a raised shoulder-thing-that-goes-up to California.
Sigh.
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Miguel is bound and determined to make me buy a larger safe, it seems.
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And now Mrs B has starting our search for a retirement location, starting with Tennessee.
[Laughs in evil influence]