This is a series 3 handguard.
The Diamondhead Handguard has an internal diameter of 1.35" and should be compatible with a Superlative Arms piston setup. Superlative Arms lists the Midwest Industries Combat Rail as being compatible, and it has internal diameter of 1.3". You can contact Superlative Arms directly to confirm compatibility.
I would recommend emailing us at techsales@opticsplanet.com to help you further.
Yes it does.
It is a series 3
I would recommend emailing us at techsales@opticsplanet.com to help you further.
Inside of handguard is 1.35"
It weighs 0.96lbs with the barrel nut.
This should work but the front of the gas block on top might be slightly exposed. Mid-length gas systems have the hole at 9", but the front of the gas block will be closer to the 9.5" mark. This handguard is 10.25 at the longest point, but the cutback is more than an inch, so you'd be at around 9" on top, leaving around 1/2" of the gas block exposed.
No, it is meant specifically for a small frame AR-15 upper receiver.