458 SOCOM won't go into battery

[Hornett]

UPDATE #2:

I called Tromix to order a couple of magazines and who should answer the phone but Tony Rumore in person.
It was after hours (I didn't know) and he just answered because.
He took my information and cc # and said the magazines would be on the way.
He was very gracious and answered some of my questions.
He told me I did not need center feed followers, but with his modified mags I could eliminate the magazine as an issue.
He told me he doesn't use the o rings either, just the extra power springs in the extractor.
Then he gave me this jewel.
You have to blend the receiver into the barrel feed ramp to feed the flatter nosed bullets.
The picture on the right at the top of the page shows how they do it.
http://www.tromix.com/458-socom-parts-1.html
HE said they would do it for $20, but all they do is dremel it out and polish it.
That explains the shells ramming straight into the receiver and jamming my gun.
He also said they work on a lot of Radical Firearms uppers. (sigh)

 

[halfmileharry]

Ramp and throat job (in old 1911 terms) for smoother feeding.
Wow! You are making real progress now. You still retain the right to vent on this brand AND you get a couple extra bonus bones on your "Man Card" on this one.

 

[DocIndy]

Tony is a great guy. If anyone knows the inner workings of a 458, it's definitely him.

 

[cncswiss1]

the wilson lancers are sweet, the modifications are bending the feed lips a tad to allow the rounds to "present" in a more "bullet up" orientation.

which is how one fixes steel mags that Jam- a little wiggle on the lips with some needle nose pliers works magic.
the pic below shows how my lancer mags from WC present the rounds much more tip high

 

[SSGSAD]

Boy, I learn so much here !!!!!

Thank you all !!!!!

 

[Hornett]

the wilson lancers are sweet, the modifications are bending the feed lips a tad to allow the rounds to "present" in a more "bullet up" orientation.

which is how one fixes steel mags that Jam- a little wiggle on the lips with some needle nose pliers works magic.
the pic below shows how my lancer mags from WC present the rounds much more tip high

Maybe the mags I 'modified' aren't ruined after all.

 

[Hornett]

I got the Lancer mags from Tromix last night.
The bluntest nosedest ammo I haves feed every time so, .

I have the right extractor spring.
I have the right magazines.
But this just keeps getting more interesting.
If I manually feed rounds, I get this (with 3 rounds loaded in the mag).
And it jams like this every single time.

It looks like they did not complete some machining there on the upper receiver.
Does anyone else think I should take a file to this.
If I do the little door won't ever close anymore.
Can you post some pics of your receivers for comparison?

 

[jinks]

Can you post some pics of your receivers for comparison?

Here is a picture of Aero Precision's 458 SOCOM upper receiver.

https://aeroprecisionusa.com/media/...11300-458-socom-stripped-upper-receiver-1.jpg

And their standard receiver.

https://aeroprecisionusa.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/a/p/apar501602-ar15-stripped-upper-receiver-with-flag-1.jpg

 

[sht4brnz]

It does look like some incomplete machining

 

[Hornett]

Thanks Jinks.
That helps.
If you zoom in on that Areo P upper I see that they also did not machine the top of the ejection port completely.
BUT there is more material removed than on mine, so, it looks like its time to break out the files.

 

[Hop]

I'm not sure how I missed this thread but...

What you should search for are some early p-mags with the V shaped follower guide at the front. Gently file a small bevel onto that V and it will kick the ammo nose up & feed hollow point ammo just fine.

There's a spec for opening up the ejection port. Mine is large enough that the ejection port door spring leg is too short, comes off, and my cover goes flabby.

I still have some of the bad Corbon ammo. Coupled with the rough RRA chamber made for a very frustrating rifle. Some Flitz and SBR ammo and it ran great. It smoothed out enough that it finally cycles the Corbon ammo too.

Mine runs fine on a factory RRA lower with a standard 5.56mm carbine buffer / spring combo.

 

[slowmo]

It looks like they did not complete some machining there on the upper receiver.
Does anyone else think I should take a file to this.
If I do the little door won't ever close anymore.
Can you post some pics of your receivers for comparison?

If you decide to take open up the ejection port with a file, be careful that you don't remove too much from the top. As you mentioned, the detent on the cover will not engage to stay closed if you remove too much material. You should be able to find drawings and specs with a quick google search. Total opening should be 0.620"

 

[Hornett]

Latest update.
I don't think filing is necessary.
I compared it with a friend's rifle here in Bedford and mine is actually opened up MORE than his was.
He only shoots pointy end ballistic tip which are easier to feed than my big flat nosed hollow points.
I did not have time to take it out and actually shoot it this weekend.
BUT, he suggested I try the action with an empty case.
And, like magic, empty cases eject just fine when cycling by hand.
The bolt holds down the top round until it moves past the end of the next round in the magazine.
When ejecting a loaded round like I was experimenting with, the ejection is delayed until the bolt had moved past the top round in the magazine.
Obviously a loaded round is longer than an empty case. duh
The empty case did not interfere because it is shorter than a loaded round and it clears the chamber before the bolt moves past the end of the top round.

So,
A. I am dumb, I should've thought of that.
B. Live fire testing needs to happen soon.
C. Jobs can really interfere with important shooting stuff.