LWRC problems FTF, etc.

[30calDeath]

So today I took my LWRC REPR out to the Angeles range out in Los Angeles and proceeded to put 100 rounds of various grain Southwest Ammunition down range. Well right off the bat I had problems like very light primer strikes and the result would be a no fire. Then it would have problems loading ammo out the 10/30 Pmags. It almost seemed like the spring was getting hung up inside the magazine therefor resulting in the round not being pushed out the mag with enough force. So with that problem the bolt would not be able to catch the round and would grind itself into the round ruining the round.

So basically it was the mag and the light primer strikes problems that plagued me all day. When the rifle shot it shot some pretty decent groups at 100 and 200 yards, even shot out to steel at about 300 yards. The ammo that I had the problem was the FC head stamped brass, I also had a box of Winchester branded brass and still had the problem but maybe had 3 or 4 problem rounds out of the box. So it seemed less trouble some than the FC brass. This ammo was all from Southwest Ammunition. I didnt run a box of any factory ammo as the day was getting late so we decided to pack up and leave. Overall I had a fun time just would like to get these problems resolved. Oh a few times after the mag was empty the bolt wouldnt lock back into place. The rifle has a Magpul UBR stock along with a Slash's buffer and modified Armalite AR10 spring.

Ill try to get some pictures of the ammo and how the bolt just tore it to hell.

 

[Direct Assault]

Re: LWRC problems FTF, etc.

I have had similar issues but mine was due to the buffer being short stroked. Like the spring was too stiff or got hung up on the way back. The issue was all ammo related. I never had and light strikes though. Im interested in the outcome. Good luck man.


Also the UBR may be the wrong extension set up for a repr. Don't quote me but I think the UBR was never designed to work well on an ar10 platform (extension too short for buffer). Just a brain storm

 

[5872]

Re: LWRC problems FTF, etc.

Is it by chance a pre 2000 serial number?

 

[30calDeath]

Re: LWRC problems FTF, etc.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DirectAssault</div><div class="ubbcode-body">I have had similar issues but mine was due to the buffer being short stroked. Like the spring was too stiff or got hung up on the way back. The issue was all ammo related. I never had and light strikes though. Im interested in the outcome. Good luck man.


Also the UBR may be the wrong extension set up for a repr. Don't quote me but I think the UBR was never designed to work well on an ar10 platform (extension too short for buffer). Just a brain storm </div></div>

I ended up using a Slash's buffer and modified AR10 spring that was supposed to cure that problem.

 

[30calDeath]

Re: LWRC problems FTF, etc.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 5872</div><div class="ubbcode-body">Is it by chance a pre 2000 serial number? </div></div>

I do not know, how can I tell?

 

[Fongman]

Re: LWRC problems FTF, etc.

So did you test fire it with the original/factory spring and buffer? If not, you might want to try that first before you start substituting aftermarket parts.

 

[30calDeath]

Re: LWRC problems FTF, etc.

No i sold off the tube, spring, buffer and stock that was on there when i got it. So far i think it is the ammo, wont know till next time i fire it though.

 

[5872]

Re: LWRC problems FTF, etc.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KillZone45</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 5872</div><div class="ubbcode-body">Is it by chance a pre 2000 serial number? </div></div>

I do not know, how can I tell?</div></div>

If the SN of your rifle is less than 2000, it may need to go back to the factory for a mod. 5872

 

[30calDeath]

Re: LWRC problems FTF, etc.

Took the gun out today and shot 60rds through it, only had maybe 4-5 FTF. Shot a lot better, used factory Winchester white box ammo. Me and a buddy are thinking it is the buffer spring needs to get broken in. I have about 160 rds through it now and am going to try and put 100 rds through it every time till the problem goes away. If not then we are going to look at a few things. The ammo could still be suspect though, we will see.

 

[Direct Assault]

Re: LWRC problems FTF, etc.

Man thats weird! I hope you get it worked out. You could buy some nice match ammo and try that. I have heard cheap ammo short stroking a new buffer springs but it was steel case wolf cheapo special. My .308 likes 168 SMK. My bolt gun likes 155 amax. Those are my favorites at least.

 

[Fongman]

Re: LWRC problems FTF, etc.

Make sure you clean it really well - if you haven't already. And that it's lubed adequately afterwards. Check to see if the feedramps are smooth into the chamber.

Sounds to me like you may have to go back to the factory spring and buffer. Spring should not have to "break in" if it's the right strength to begin with.

FYI I always shoot a factory gun first the way it arrived from the factory. Then if I decide to add aftermarket parts I do them one part at a time. It eliminates the variables much quicker.

Contact CS if you still have problems - LWRC will take care of you.

 

[chainring]

Re: LWRC problems FTF, etc.

Yeah, I'm gonna reserve judgement on that one until you shoot it with the original configuration, the repr spring and buffer is made for the repr. Talk to CS about what they recommend for a ubr, if you haven't yet. This sounds simple, but you might make sure it's on the N normal setting at the gasblock? Need to lube and spin that selector routinely during break in, anyway.

 

[chainring]

Re: LWRC problems FTF, etc.

Looks like you should have kept the original spring and buffer unless yours came with the PRS, which is a rifle length receiver extension. In that case you would have needed to order a factory spring and buffer for carbine length extensions.

http://forum.lwrci.com/viewtopic.php?f=30&t=12272

 

[30calDeath]

Re: LWRC problems FTF, etc.

It could very well just be weak ammo too, the Winchester white box ran pretty damn well considering the circumstances. The Winchester was rated at 2750fps versus the Southwest at 2650fps, so that that as you will.