Problems with my new Rock River Arms 458 SOCOM.


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marksman13
June 10, 2012, 04:13 PM
I took my new Rock River 458 SOCOM upper to the range this morning. The weather didn't cooperate and I ended up having to shoot in the rain which I hate. The rain was just the beginning of my troubles.

To start with, the recoil was fairly stiff and I attributed some of my shooting woes to an adjustment period at first. To sum it up, I was shooting all over the place. High, low, left, right and everything you can imagine. I'll be honest, I was a little startled with the recoil. It wasn't punishing by any means, but it was just heavier than I was accustomed to from an AR15.

I shot a few more after I settled in and it was better, but it was still inconsistent. At this point I was pissed off at the rain and my shooting, not to mention the $3.00 I was burning every time I squeezed the trigger, so I started picking up my brass to head home. What I saw caught me by surprise.

Of the 19 rounds I fired, 15 had split cases!!! Most of them also had damage to the rim of the case, some of it severely gouged. I tried to take pictures of all the damaged cases.

The ammo was factory loaded Corbon Hunter 300gr rounds. The upper is a Rock River Arms CAR A4 upper. The lower is a Spike's Tactical with a RRA two-stage match trigger.

I think it's either some hot-loaded factory ammo or a poor head spacing job by RRA. I'm going to give them a call first thing in the morning to see what they say. I'm pretty sure if the issue is on Rock River's end they will make it right. Here's the pictures.
166004
166005
166006

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Trent
June 10, 2012, 04:17 PM
That's bad headspacing. (It's not getting a good mate on the shoulder of the chamber, to the shoulder of the brass).

Defective.

Send it back, they built it wrong.

Trent
June 10, 2012, 04:19 PM
(Just to be SURE, measure the CORBON ammo to make sure THEY did it to spec; I suppose it's possible they had a bad batch of brass with a shoulder that was set back too far.)

Grumulkin
June 10, 2012, 04:20 PM
I don't see significant scuff marks on the body of the case so I'm thinking the load isn't too hot. It could be a bad chamber but I think bad brass is more likely.

marksman13
June 10, 2012, 04:20 PM
That's my thoughts. Wouldn't be as bad if I hadn't burned $60.00 in ammo.

marksman13
June 10, 2012, 04:23 PM
Grumulkin, does it not look like the headspace is too short because of the way the bolt is digging into the rim of the case. That coupled with the split cases makes me think it's headspace. I've never had an issue with Corbon ammunition before.

Trent
June 10, 2012, 04:23 PM
PS I hot loading ammo wouldn't cause that; the split would be at the other end of things and the damage tends to be more on the "catastrophic" end of things.

There's too much space between the shoulder of that ammo and the shoulder of the chamber. If the ammo measures to spec, then the barrel+barrel extension with the locking lugs was not done to spec; rifle needs to be rebarreled.

dprice3844444
June 10, 2012, 04:25 PM
contact the maker

Trent
June 10, 2012, 04:32 PM
Also, assuming a set-back shoulder during ammo manufacturing isn't the cause, if that barrel is THAT far out of spec - it'd take a LOT to give it room to split the case - I'd be more than a little upset. Something that far out should have NEVER made it out of the factory.

Assuming the ammo is in spec, it'd take a chamber that's out of whack by a good .015 or more (gut feeling) to give it room to split that far.

Can you post up a side-by-side view of the Unfired ammo vs. the Fired ammo (assuming you have any unfired left?)

*Really* curious to see how far the shoulder got pushed out.

Trent
June 10, 2012, 04:36 PM
One last thing. The reason the back of the cases are getting battered;

When the firing pin strikes it'll "shove" the case forward until the shoulder makes contact. (You SHOULD also get a fair amount of "FTF" on the first pull, if it's bad enough)

Then when ignition happens the case is blown BACKward until it makes contact with the bolt head. (Not good on the bolt, by the way!).

THEN the case GROWS forward again, due to the pressure, which is when the case splits. (Not good on the chamber, or the rest of the gun, by the way, as now you have uncontained gas getting OUT of the casing and trying to get along the sides of the case; not to mention now you have a little high-powered 20,000 psi jet of gas burning the living hell out of your chamber.)

So you end up with battered brass on the back side, split shoulder, a severely beaten bolt head, and a hell-a-fouled chamber.

Bad news all around.

jmorris
June 10, 2012, 05:09 PM
I've loaded hot enough with mine to flaten the primers and mess up the rim but have never had a case split like that.

JPG19
June 10, 2012, 05:12 PM
I'd send it back and pickup a matching Spike's Tactical upper, but that's just me :)

Trent
June 10, 2012, 05:13 PM
With a properly supported chamber, a hot load won't cause a blowout on the front.

It'll blow out where the round is not supported by the chamber.

(E.g. around the circumference of the webbing of the case - case head separation, or from the primer pocket out.)

Both are highly dangerous.

What his cases show aren't especially *dangerous*, but not good for accuracy, cleanliness (chamber fouling) OR from a reloading standpoint. Losing 75% of your brass to structural failure due to bad chambering is certaily not trivial, considering the cost of brass.

redneck2
June 10, 2012, 05:49 PM
If I split that many cases I'd be all kinds of pissed

If you want to send me some of the split brass, I'll try to check it with my reloading dies to see how much the shoulder gets set back when it's run thru a sizer die. I can also compare it to my fired brass

As for recoil, better get used to it. In the world of recoil, the SOCOM's not all that bad. I've got an 870 that shoots 3" Copper Solid sabots. The SOCOM is a pussycat after that.

Of course, that's the reason I'm selling the 870 and using the SOCOM for deer.

marksman13
June 10, 2012, 05:56 PM
I'm not recoil sensitive. I've just shot ARs in 5.56 for a long time and I guess I have a certain muscle memory for the way I shoot them from a bench and if I were to shoot this rifle the way I shoot those I would have had a nasty scope ring. It's not bad at all on the shoulder. It's my jaw that seems to take the worst of the recoil.

marksman13
June 10, 2012, 06:31 PM
Also, assuming a set-back shoulder during ammo manufacturing isn't the cause, if that barrel is THAT far out of spec - it'd take a LOT to give it room to split the case - I'd be more than a little upset. Something that far out should have NEVER made it out of the factory.

Assuming the ammo is in spec, it'd take a chamber that's out of whack by a good .015 or more (gut feeling) to give it room to split that far.

Can you post up a side-by-side view of the Unfired ammo vs. the Fired ammo (assuming you have any unfired left?)

*Really* curious to see how far the shoulder got pushed out.

166012
The round looks to be in spec to the naked eye. At least the bullet doesn't appear to recessed back into the case. It doesn't look like the shoulder has been pushed out very far either, though if I spin the case it looks as though the shoulder is no longer concentric to the rest of the case. I guess what I'm saying is that it looks as though the shoulder has been blown out on one side but not the other.

marksman13
June 10, 2012, 07:02 PM
JPG19, gonna be kind of hard to get a Spike's upper considering they don't make a 458 SOCOM.....

JPG19
June 10, 2012, 07:38 PM
Excellent point. Whoops!

marksman13
June 10, 2012, 08:03 PM
JPG19, haha. I looked at every manufacturer I could think of for a 458 SOCOM. Rock River seemed like the best balance of quality and cost. I feel confident that Rock River will resolve this issue quickly and professionally. I'll keep everything updated as the process plays out.

Trent
June 10, 2012, 08:28 PM
That's a bad chambering job with incorrect headspacing. The "one side pushes more than the other" is due to the case expanding inconsistently until it splits. Once it ruptures, then gas pressure equalizes inside and outside the case, and it STOPS expanding further.

Assuming the CORBON ammo is in spec, that is a bad barrel assembly. Needs to go back.

marksman13
June 11, 2012, 09:38 AM
Update 6/11/2012:

Talked to BJ at Rock River Arms this morning, very professional guy by the way. I described the issues I have had with my upper. Long story short, they are sending me a shipping label and scheduling a UPS pick-up of my upper on their dime. This is the first sign of good customer service to me. I am sending the upper and spent casings along with empty Corbon ammo box to them. I believe they will resolve the issue quickly. We shall see.

repmurcs
June 13, 2012, 09:11 AM
That's good news --- I got my RRA 458 about 2 weeks ago - Haven't sent a single shot down the barrel yet. You had me scared with this story. Now I gotta go make time to do so, to make sure it's not a common issue. I LOVE THIS WEBSITE ..

Tex4426
June 13, 2012, 10:36 AM
Redneck2 what accuracy are u getting out of your 458...im getting ready to build one for deer hunting and would like to be able to stretch it out to 250 yards if possible....do u guys think the recoil on this will beat up an eotech 512 or should it handle it

repmurcs
June 13, 2012, 12:13 PM
After having many months to research add on's for my 458 - EoTech 512 seems to be the Optic of choice --- that and ACOG but ...
For a cheaper version (yet to be proven) Mueller Quick-Shot is something I've been toying with I've even contacted Mueller - they stated that these are sold to Turkey hunters and handles the recoil of a 12 Ga. Turkey Load just fine. All speculation though

redneck2
June 13, 2012, 07:27 PM
Redneck2 what accuracy are u getting out of your 458...I'm getting ready to build one for deer hunting and would like to be able to stretch it out to 250 yards if possible...Maybe 1.5" at the very best. Not a tack driver, but adequate. I consider it a 150, maybe 175 yard gun at the very best.

If you hand load and you're looking for something Indiana deer legal, get ahold of D-Tech in Bemidji, Mn. I got an upper based on a .25 WSSM necked up to .358. It's a true 250+ yard gun. Mike's got the dies, brass, loads, everything. Builds the upper with a Shilen match grade barrel. Cost is maybe $900.

Darkbob
June 15, 2012, 08:57 AM
I'm going to keep an eye on this thread to hear what the resolution is from RRA.

As far as optics go, I don't have an Eotech but I do know that the recoil from my SOCOM is too much for the Primary Arms red dot that I tried to use. It took me a half dozen rounds to figure out that the sight was not holding zero.:banghead: The PA sight now sits on my AK, and I have mounted a Nikon 2x7 shotgun scope on the .458.

marksman13
June 15, 2012, 09:07 AM
UPS picked picked up my upper on Tuesday. I'm not sure how they handle things, but I hope they call me once they diagnose the issue and give me an estimate on when I should have it back.

I may end up swapping out the Nikon for an Aimpoint before all is said and done. I like magnified optics for hunting, especially in low light, but the Aimpoint PRO would be handier.

Tex4426
June 15, 2012, 09:21 PM
i do mostly brush hunting and most shots are within 75 yards...which is why i like the socom..a carbine length gun with that much knockdown energy..i fell in love instantly..i plan on mounting my 512 on it since acquiring a target fast is sometimes need..then there will be a flip to side magnifier for those longer difficult shots...1.5 inch group with a 458 bullet is very good in my opinion...especially if thats outside diameter of the group

marksman13
June 18, 2012, 06:41 PM
Had a local reloader tell me that the issues with my rifle were brass related. He told me this based only on pictures. He said he would be surprised if Rock River doesn't call me and say that my rifle is fine.

Does anybody here think this is a brass related issue?

NG VI
June 19, 2012, 08:36 AM
I say let 'em fix it and evaluate the rifle with a fresh mind when it comes back. It's a manufactured good, as disappointing as it is to have it come from the factory with some issue, these things happen.

Cor-Bon charges too much to have that poor quality control. I can't imagine they'd be caught dead running brass that caused problems like that unless they got an entire lot of bad brass, and then I'd imagine they'd hear about it and try to replace it quickly.

marksman13
June 25, 2012, 01:18 PM
Still no word from Rock River about the status of my 458 SOCOM.....

marksman13
June 28, 2012, 04:23 PM
Spoke to BJ today. My upper is being shipped back to me tomorrow. They did not find any issues with it. BJ said all they could figure was hard brass. Apparently Corbon had an issue with a batch of hard brass a while back. The ammo I was shooting was pretty old, so this could be my problem. I'm going to try it out when it comes back.

bbq fan
June 28, 2012, 05:09 PM
Hope it all works out for you. Btw I have a long term plan of building a .458 Socom some day... It would probably be a great hog gun.

Darkbob
June 28, 2012, 06:11 PM
So are you going to try to get a free box of ammo from Corbon? If they had known issues with the lot your ammo came from I'd hope that they'd send you another box to compensate. You should at least let them know that RRA said that the ammo was the culprit.

B!ngo
June 28, 2012, 06:59 PM
What is 'hard brass'?
B

p2000sk
June 28, 2012, 07:16 PM
I am not a reloader, but brass or copper can be hardened by annealing it, or softened by annealing it again. This can be useful to straighten a hard pipe or soften one to bend it. Here is a link about annealing brass:
http://www.youtube.com/watch?v=kgD5D0Wzu-c

marksman13
June 28, 2012, 07:21 PM
I'm going to email Corbon in the morning.

Welding Rod
June 28, 2012, 08:59 PM
Thanks for the update. Please let us know what Corbon says.

marksman13
July 2, 2012, 07:18 PM
Received an email from Cor-Bon very early this morning. They are paying the shipping for me to send the ammo, including the spent brass back to them to see if the problem is on their end. At any rate, it sounds like they plan to replace all three boxes.

The ammo I bought was pretty old, 2008, and that may have been part of a bad batch that supposedly came out around them. That is pure Internet speculation and Cor-Bon did not make any mention of a bad lot in their email correspondence.

If the ammo proves to be the issue then I would have to say I am very satisfied by the way both companies handled the situation.

repmurcs
July 3, 2012, 07:23 AM
What type of Cor-Bon ammo was that you had an issue with ??

marksman13
July 3, 2012, 08:25 AM
Cor-Bon Hunter 300gr. Lot number is from 2008, so it's an old batch.

Trent
July 3, 2012, 12:13 PM
Good to hear the problem is getting solved!!!

I'd hold on to a casing (if you have to ship the defective ammo back) just to see where the neck position is - comparing old vs. new.

Still suspicious if it wasn't headspacing then their ammo might have been loaded with a pushed-back shoulder. It'd take something considerably out of spec to expand THAT damn far, far enough to split.

marksman13
July 3, 2012, 10:31 PM
For some reason Rock River kept the brass. I'm going to call BJ about that after the holiday.

marksman13
July 13, 2012, 05:37 PM
Got the brass back from Rock River this week. Suddenly Cor-Bon doesn't want to return my emails.....

marksman13
July 16, 2012, 06:44 PM
Still no word back from Cor-Bon. This is getting a bit ridiculous. Last contact I had with them was over a week ago when I was told to send them an email when I had brass back from Rock River. I emailed them last week to confirm the brass was back in my possession. Still no call tag for me to send the brass to them. I don't care if I get my money back or not at this point. I just want Cor-Bon to confirm or deny that the brass is the issue.

Special Projects
July 16, 2012, 07:43 PM
Have you had a chance to try some different ammo yet? Any issues?

marksman13
July 17, 2012, 08:56 AM
No. I haven't tried any other ammo. I wanted to make sure it wasn't an issue with the rifle before I went out and ruined more brass.

wally
July 17, 2012, 09:58 AM
I wanted to make sure it wasn't an issue with the rifle before I went out and ruined more brass.

Generally when a new gun is having problems, a different brand of ammo is the first thing you should try before sending anything back.

While I'd quickly get rid of a gun that showed a lot of ammo sensitivity, tolerance stack-up sometimes means some lots of ammo just won't work well with some guns.

marksman13
July 17, 2012, 09:26 PM
Wally, I agree to an extent, but splitting brass just isn't acceptable in my eyes no matter the make of the gun or ammo.

Tried it tonight for the first time since I got it back from Rock River. It was a different lot number, but it still split two out of the six cases. This is beginning to get ridiculous. I'm almost to the point of selling the rifle and moving on to something else. If Cor-Bon does not get back to me by tomorrow then I am done with their products for good.

marksman13
July 18, 2012, 10:43 AM
Heard back from Cor-Bon this morning. All the ammo and brass is headed back to them in the morning. Sounds like they are going to make this thing right. We'll see.

marksman13
July 19, 2012, 06:28 PM
Ammo shipped back to Cor-Bon this morning.

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