Hi All!

I am helping a friend swap the barrel on his DPMS Panther LR-308.  The orginal setup is a 16" carbine length gas system.  He swears that when he bought it years ago he swapped the plastic handguard for a AR15 drop-in quad rail.  It is a Knights Armament handguard and googling makes believe he is correct.  We are switching it to a mid-length gas system to open up barrel options.  My standard AR15 armorers wrench worked fine for removing the barrel.  I am hoping we can utilize a mid-length drop-in handguard (looking at the one from Midwest Industries) but am open to other options.  Google and forum searching gets real confusing.  There were lots of different setups it seems like.  Any input?  TIA!

-Jeff

There are 3 different upper heights on the LR-308/AP4 series.

If you want the upper to match with a rail on the handguard, you need to find out which one it is first.

Here are the 2 different AP4 heights:



Here's the LR-308 upper: