First Build Issue

[liquormann]

Well here's the dilema guys, I built this LR-308 with every single part made by DPMS for the lr-308 except for the buffer, spring, buffer tube and stock. I went to a friends house yesterday to fire this thing at his range. After firing the weapon, everything seemed to be ok until I pulled the trigger the 2nd time. When i went to pull the trigger, It was almost like the safety was on. I pulled the charge handle a second time to clear the chambered round and chambered another round,fired off a round and again and the same thing. Pulling the trigger felt like it was on saftey when it wasn't.

 

Any help would be appreciated.

[shibiwan]

Do you have the correct buffer/spring combo? The 308's can use a standard AR15 buffer (rifle or carbine) but requires a different spring/buffer combo to work correctly.

 

-S

[liquormann]

Do you have the correct buffer/spring combo? The 308's can use a standard AR15 buffer (rifle or carbine) but requires a different spring/buffer combo to work correctly.

 

-S

I think i do. I used one from heavybuffers.com

[seasprite]

When you let off the trigger after the first round can you feel the trigger reset and the disconnector release the hammer to the sear?

[liquormann]

When you let off the trigger after the first round can you feel the trigger reset and the disconnector release the hammer to the sear?

I can't say that i can.

[edgecrusher]

What about extraction? Are you running a standard or adjustable gas block? Exactly what buffer stock tube combo are you using? Btw, welcome

[shibiwan]

With an empty magazine, can you pull the charging handle far enough for the bolt catch to engage correctly (i.e. on the bolt face and not on the bolt carrier)? If the buffer is the incorrect one (too long) the BCG won't pull back enough to catch properly.

 

If it engages correctly you should be OK on the buffer. Next, try putting 1 round in the magazine, take one shot and see if it cycles properly and catches on the bolt catch. That should give you a clue if you're undergassed or have the wrong spring.

[Robocop1051]

Wet wet wet wet WET WET WET... Dripping, sloppy, soupy, wet!

It sounds like your BCG isn't going fully back into battery. A little lube on the buffer doesn't hurt either.

Try soaking your BCG in oil (I actually pre-soak mine in Mobile1 full synthetic). Then, on range day, lube up your fire control group, buffer assembly and upper receiver.

The .308 needs to settle in with its parts. They are all a bit rough to start.

[Robocop1051]

Also, try using only half loaded mags. New mags have strong springs. When fully loaded in a new gun, it can be hard/rough ripping a new cartridge out. The extra work slows the BCG a bit.

[liquormann]

What about extraction? Are you running a standard or adjustable gas block? Exactly what buffer stock tube combo are you using? Btw, welcome

I'm using this spring from www.heavybuffers.com  .308 rifle buffer spring- Armalite #ea1095, rifle length buffer tube from heavybuffers.com and the factory ar10 buffer. Gas block is DPMS micro .936 for the SASS since I have the SASS barrel. Lower prts kit is the DPMS lower parts kit for a .308.

 

Thanks for the input everyone.

[blue109]

My vote for check the disconnect/spring. I had the same issue. Trigger wasn't Resetting.

[liquormann]

My vote for check the disconnect/spring. I had the same issue. Trigger wasn't Resetting.

That's exactly what it is. Took it apart and it's apparent that i forgot to put it in. THANKS Blue

[blue109]

Thank the guru 98Z5V. He's the one who fixed me up when I did the exact same thing lol

[survivalshop]

Lets look at your fire control group , you say all oem DPMS parts ?

 

Separate  your lower from the upper so you can see the fire control group in the lower receiver . Put a piece of rubber or some thing soft in front of the bolt catch where the hammer will not slam into it when testing the fire control group . Check the safety , is it working properly or hindering the function of the trigger group. 

 

You can hang on to the hammer to slow the drop , if you want , but just see hows its all working in there  & if nothing out of the ordinary jumps out at you ,Disassemble & examine all components for abnormal wear or machining marks or burr's . 

 

You can test the FCG ,( with out the upper receiver assembly ) with out the safety installed ,just to see how the trigger group functions with out it .

 

Make sure the disconnect moves freely in the trigger pocket & nothing is binding . 

 

Yes, run a new build wet for a while . I also think the rifle is not consistently  going in to battery , but doesn't hurt to inspect the FCG.

 

Damn , I must be a slow , good you found the fix.

Edited September 2, 2013 by survivalshop

[Robocop1051]

Damn , I must be a slow , good you found the fix.

Now that's funny!

[seasprite]

My vote for check the disconnect/spring. I had the same issue. Trigger wasn't Resetting.

 

Ya I had a feeling it was something with the disconnect but I just didn't know where to take him from there, way to go blue. 

[unforgiven]

On my first 5.56 lower build I banged it out pretty quick.Then I saw I had an extra part on the table [Disconnector spring] ooopps.

[MikedaddyH]

Wet wet wet wet WET WET WET... Dripping, sloppy, soupy, wet!

It sounds like your BCG isn't going fully back into battery. A little lube on the buffer doesn't hurt either.

Try soaking your BCG in oil (I actually pre-soak mine in Mobile1 full synthetic). Then, on range day, lube up your fire control group, buffer assembly and upper receiver.

The .308 needs to settle in with its parts. They are all a bit rough to start.

Sloppy wet lube running down your are and dripping on the floor !

Ya I had a feeling it was something with the disconnect but I just didn't know where to take him from there, way to go blue.

Check the disconnector may have to swap out for another or an adjustment by the selector (some have a screw below in the bottom of the lower)

 

 

My vote for check the disconnect/spring. I had the same issue. Trigger wasn't Resetting.