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Drop in Trigger Won't Clear Bolt

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Hi all,

Don't know how active this thread is.  I have a DPMS LR-308.  I am not sure if it is gen one or two, but I believe it is II because it doesn't have  a forward assist, has a chrome lined barrel and it is a free float with a flat top all the way across and I believe it is one of the "lower" set ups for the following reasons.

I'm on drop in trigger number 2.  Don't buy a wing, they are junk, I installed it correctly preformed the safety check and it snapped in half at the thinnest point of aluminum on safe with my hand over the hammer (I'm having real problems with the return to retailer but until they completely f me I'll leave them alone.)

So I decided to go with an Elftman AR-10/308 adjustable trigger, so much nicer. Got it installed, performed all the safety checks, loved the feel, put the top on, go to rack it and boom rack gets stuck.  Figured out the rack is not clearing the hammer.  I tapped the hammer and saw that there is clearance from where the hammer strikes the pin to the top of the hammer thats giving me problems.  My only thought is to start lightly sanding it and see if I can get the "trigger group" to clear the hammer.  by removing a pin and jacking the trigger up with its internal pins I have been able to get the trigger to function, but that angles it in such a way that it no longer catches the safety and that's probably not good on a trigger with a sub 3# pull.   

Have any of you had issues like this and know if my idea will work?  Have any of you had success with drop in triggers?  I've emailed the sales department of this particular retailer who advertises this as fitting the DPMS, but doesn't want to take "installed parts" back as well.  If they also screw me, I'll probably sand and ultimatly grind away to see if I can get the bolt to clear, I'm sort of waiting on their reply given I think the other company is going to jerk me around on a trigger that, I'M LUCKY BROKE, because even if it had cleared the bolt (which I never got to find out) it would have broken the first time the trigger was on safety and engaged the hammer into the primer of a live round.  


Thanks for any input.


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16 hours ago, EB1 said:

I have a DPMS LR-308. 

All DPMS LR-308s are the original design, and not a DPMS G II.  All the G IIs are not marked LR-308. 

Is this a lower you built/machined, like somebody's 80%, and you're calling it a LR-308, or is it a real DPMS we're talking about here.

Has this gun ever fired before?  You've shot it?  Or is this all a brand new build?

Need ALOT of information on all the parts used, if you built it.  If you purchased is from someone, it could be a FrankenGun, put together with all kinds of shiit.  DPMS never made an upper for the LR-308 that didn't have a forward assist, unless it didn't have a shell deflector also.  THey made a slick-side that doesn't have either, but if it's got a shell deflector, and no forward assist - it's not a DPMS upper receiver.  The DPMS LR-308 upper receivers are pretty distinctive - nothing else on the market or made ever looked like them.  They were made from an extrusion.  

Here's the slickside "target" upper, with that huge rail:

enlarged product image

Here's what the rest of the DPMS LR-308 uppers look like - the forward assist was always incorporated into the shell deflector:

enlarged product image

Hope that helps...

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It looks like the one in the top, no deflector or forward assist. Here are some photos, I have shot it shots and cycles well (REALLY trigger wasn't too bad, but this has become my White Whale). Now that I've combed though it, it doesn't appear to be a rebuild (no scratchs at least or shotty workmanship). Here are some photos. I've narrowed the issue down to the bolt won't clear the Elf trigger. I'm awaiting optics planet to tell me if they'll let me file off the top of the trigger and return it if it won't work. Here are some pictures. If you pay close attention to the hammer you'll see where the bolt is ramming into it.

The picture of the hammer is the original. I'm including it to show the difference in shape from the drop in.

I got a heck of a group at 100 I included but I really had to work the original trigger to get it there.









Edited by EB1
Typos from using phone
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Yep, that's a legit old DPMS LR-308, with their target slickside upper.  Serial number end in a "K"?  That'll tell you if it's a factory built LR-308, or if someone built it from stripped receivers.  All the stripped LR-308 receivers they sold had a "K" stamped at the very end of the serial number.  

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No, the serial number is six digits in the 150ks, but no "k"

I was able to painstakingly file that hammer down and its like butter now. Can't say enough about optics planet. They were willing to take it back even though it was installed but the tech also searched and said every trigger he found he read into the forums and everyone said they required mods on that particular gun, a lot being on the reciever, so he said, if you think you can do file down just the hammer and you really want it, go for it, but if it doesn't work it's yours. I took the blue pill.

Took my daughter's driveway chalk and dusted the hammer with it. Masking tape over the hammer and marked where the strike occurred. Then wrapped the lower in plastic so no shards got into the trigger group, taped it all up, filed slowly, shop vacked the plastic removed, shop vacked the trigger group and well of the lower, tested; rinse and repeat for 3 hours.


It's cycling like butter now. I'm bundling up and hitting the range first thing. I did the chalk test again and hammer is still making perfect contact with the firing pin so I full expect the gun will function. I was tempted to pull a bullet out of the casing, dump the powder and see if it would ignite a primer but I live in a neighborhood and decided I'd tempted luck enough for the night and came out (apparently) ahead.

I'll post my final results tomorrow for anyone who ever has this issue.

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