I bought a LR-260H last year,and it had a few hiccups out of the box. It short cycled badly,and wouldn't hold the bolt open after the last round was fired.DPMS customer service was of little help.
I told them it had a very heavy buffer spring in it,and was told they only offered one type of spring for the LR series.
I messed with it for a couple weeks trying to figure out what was wrong-I have built several AR's over the years,so I'm very knowledgable of the platform.
After messing with the spring,I ended up cutting off 3 coils-1 at a time,to make this gun cycle. I also noticed that this spring was painted Red on the end,just like the Heavy spring I use in my 458 SOCOM for 500+ gr bullets.
I stopped by the dealers shop where I purchased it,and asked if he had any factory buffer springs for the LR series in stock.The one he came out with was painted Yellow on the end.I installed that spring,and it was like night and day in the spring weight. I shot the rifle when I returned home with the Yellow spring,and it worked just like it should.
I called DPMS again,and told them about the Red spring,and they accused me of putting it in the rifle,but it was the spring that came in the rifle from DPMS. The rifle was in a factory case,sealed inside a cardboard box from DPMS,and I watched the dealer cut the tape on the box.
The factory trigger is pretty bad,and was the first thing that was changed.
Anyway,I'm very happy with this rifle. I installed an ACE stock,RRA NM 2 stage trigger,Weaver riser,Burris Signature Zee rings,and a Sightron SII 4-16x42 scope.
This rifle loves 140gr Sierra Gamekings