Building a .458 SOCOM AR

[Fryall4]

Nice job OfficerX! It is looking great. I have a .458 SOCOM, built with a Radical Arms upper. It is a beast. It lets you know you just shot a rifle, lol. I'm having magazine feed issues, like a lot of people. Youtube is a great resource for showing you the mods needed to make a reliable weapon.

[officerX]

Nice job OfficerX! It is looking great. I have a .458 SOCOM, built with a Radical Arms upper. It is a beast. It lets you know you just shot a rifle, lol. I'm having magazine feed issues, like a lot of people. Youtube is a great resource for showing you the mods needed to make a reliable weapon.

Are your issues with the mags or does the upper need to be "blended"?

[Fryall4]

Are your issues with the mags or does the upper need to be "blended"?

To be honest, it could be either and most likely both. I could get two cartridges out of one mag into the chamber and downrange and the third would hang up on it's way into the chamber. The other mag I tried... definitely a magazine feed issue. As a note, these were unmodified 5.56 GI mags. I have since read that the followers need to be modified (flat) and the feed lips altered.

I'm glad I saw your post, it will light a fire and get me back to work on it. She's just been wasting away in the gun safe

[officerX]

To be honest, it could be either and most likely both. I could get two cartridges out of one mag into the chamber and downrange and the third would hang up on it's way into the chamber. The other mag I tried... definitely a magazine feed issue. As a note, these were unmodified 5.56 GI mags. I have since read that the followers need to be modified (flat) and the feed lips altered.

I'm glad I saw your post, it will light a fire and get me back to work on it. She's just been wasting away in the gun safe

Great!

[Fryall4]

Yeah, I need a little push once in a while, lol.

I'll keep watching this thread for your progress and update with any new info.

[hk_shootr]

Take a look on 458 SOCOM Forum, tons of information

[cswpsi]

Had to post to keep the thread alive... Bump!

Someone asked, early on, about ammo. Yes, it's expensive, but if you reload, you can cut the retail by a 3rd. (And that's for the first load of new brass.) Starline sells 458socom at reasonable prices. To top it off, (I've heard, haven't fired enough to know) the brass rarely needs to be trimmed, as it is a low pressure round.

+1 for the 458socomforum mentioned by hk_shootr


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[officerX]

I'll be taking the build out for the first time next weekend. I'll report back with my impressions.

[cswpsi]

I'll be interested to hear your report. What ammo are you going to use, commercial or handloads?

I have a complete upper from Tromix and have found the chamber to be very tight. With Blackbutterly frangible, got several that would not chamber... Don't force it, if this happens... they're a PITA to extract.

My own handloads with new Starline brass worked perfectly, after bumping the shoulders back .002"

Good luck and have fun!

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[officerX]

I'll be interested to hear your report. What ammo are you going to use, commercial or handloads?

I have a complete upper from Tromix and have found the chamber to be very tight. With Blackbutterly frangible, got several that would not chamber... Don't force it, if this happens... they're a PITA to extract.

My own handloads with new Starline brass worked perfectly, after bumping the shoulders back .002"

Good luck and have fun!

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I bought ammo from Freedom Munitions. It was about $1.60/round. I won't be able to reload any time soon (time, space, start up cost) so I'm stuck buying it. I've tried to cycle a few rounds - some chambered ok, some didn't. I haven't "blended" the upper yet so I think I'm going to have to do it.