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-   -   First trip to the range with RRA LAR-8 (http://www.firearmstalk.com/forums/f20/first-trip-range-rra-lar-8-a-52479/)

BB98338 11-26-2011 10:26 PM

First trip to the range with RRA LAR-8
 
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I got a new Rock River Arms LAR-8 .308 on Friday and took it to the range.
I shot 20 rounds of Remmington 150 gr. .308 WIN and 20 rounds of Hornady Match .308 168 gr A-Max. Out of the 40 rounds I had 8 rounds that got cocked in the chamber during feeding. It looked like the tops of the rounds were hitting something as the nylon stips of the Hornady's were scraped off. I have enclosed a picture of the 8 rounds that jambed. Took it back to the store today where it was dissasembled and nothing looked amiss. The store said it may be a magazine issue. I will try it again in a couple of days and see if it gets any better. I also sent an email to Rock River Arms to see what they say. Will keep everyone posted on the issues.

mjkeat 11-26-2011 10:47 PM

I have honestly never seen anything like that before. Do you have another magazine?

FCross7 11-27-2011 12:50 AM

I've had that happen with Remington UMC. In my opinion, it is THE cheapest ammo around, and I refuse to shoot it in any of my guns. I've had bullets drop into the cases like you've got pictured, I've pulled cartridges out of the package that had the neck all twisted and torn up and I've had cartridges with no powder (had to get a gunsmith to remove the cartridge from the rifle).

I don't see how they have so many rounds slip through QC that have issues. I don't know, maybe I'm just unlucky, but I've had multiple issues, 10+, with UMC, and never have I had any sort of issue with any other factory ammo, the Russian stuff included.

I bet it's the ammo, and not the magazines or the rifle. It's normal for rounds to get a little scraped up as they leave the magazine and enter the chamber. I'd shoot a couple other brands of ammo and see what happens.

-Fred

BB98338 11-28-2011 01:46 AM

I shot 20 more rounds of the hornady today and only had two jambs. Some of the other people at the range who were familiar with ar's seemed to think it might be a magazine problem. Seems to be getting a little better with time.

FCross7 11-28-2011 03:13 AM

What were the jams? Failture to extract, failure to feed or what? I had a DPMS LR-308, and it had a habit of having failures to extract somewhat often at first, but after the first 250 rounds or so, those subsided. So if it's a new gun, it could just be a break in thing.

-Fred

BB98338 11-28-2011 04:26 AM

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This is what is happening when the rounds jamb. This is the second round trying to load after the first round extracts. In fact on examining the picture that little red thing in the chamber is the nylon tip from one of the hornady rounds.

BB98338 12-04-2011 07:56 PM

I took the LAR 8 out to the range again today. I noticed there was a little slop in the magazine that would allow it to rock forwards and backwards a little bit. If I held tension on it pushing it forward while shooting it fed much better. It may be that I have a mag that is too loose. Perhaps when it rocks rearward it causes the tip of the rounds to hit the bottom lip of the feed ramp.

Sniper03 12-04-2011 08:07 PM

BB,

Looking at your picture the first thing I noticed is your rifle Bolt Carrier Group and the Rifle is entirely too dry. You need to put some good quality weapon lube on the Bolt Carrier. It should look wet! Both Bolt, Carrier and glide surfaces. A new gun needs lube more than one that has been in service for a while, and especialy when it is new and breaking in. Personally I think that is the problem. As the others have mentioned it could very well be an ammunition problem possibly the neck is not crimped properly or the loads are a little light for the break in. I agree use some other manufactured ammunition. But above all lube the rifle. I have a RRA LAR-8 and it is very dependable. I have never had a malfunction with it. Besides RRA is as good as Gold about taking care of any issues. Keep us informed. :) The magazine issue mentioned is not out of the picture either if the problem persists

03

BB98338 12-04-2011 10:37 PM

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Hello Sniper03.
I took your advice and lubed the bolt. I also did some measurements of the slop in the magazine. The bottom of the magazine moves fore and aft 2mm. I also took a shot of the entrance to the feed ramp. I can see some wear that looks like where the tips of the bullets are hitting.

Wilder 12-05-2011 04:36 PM

It does look like a magazine issue to me. Try some magpul .308 p-mags, they are inexpensive and work great. In the pic showing the jam you can see the tip of the round under the one being fed trying to follow it to the chamber. This causes the round being fed to point too high and smashes the bullet nose into the breach face above the chamber, forcing the bullet back into the case. Scraping marks on the case will happen in any semi auto, it is really only a problem if it is leaving shavings from the case in the action. If not cleaned out these shavings can prevent proper movements of the internal parts.


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