I got this barrel and I don't know who made it or if it's for an Ar10 or LR308

Is there a way to tell the difference?

Will a headspace test with a DPMS bolt tell me? If I use a dpms Lr308 bolt and if the barrel is an Armalite Ar10 barrel using headspace gauges will they gauge the same or not pass a go or nogo guage?

Any idea what brand this is and or who made it judging but the stamping and design?

Is there a visual way to tell the difference between Lr308 and Ar10 if they are side by side?

Thank you

It is an 18" barrel with a rifle-length gas system, The marking is on the bottom opposite the side with the gas port.

Thank you

That barrel shares several features with an actual DPMS barrel that I have here:

- the milled line above the chamber in line with the alignment pin.  
- the font and size of the engraving, and its position on the bottom side of the barrel near the muzzle (although mine also says DPMS before the caliber).  
- M4 feed ramps.

If it headspaces correctly with a known DPMS bolt, I think you can safely say it's DPMS pattern compatible.

Thank you. I checked it with a set of headspace gauges and headspaces correctly.