07-07-2019, 08:13 PM
Just a quick review of my new 18" PSA Grendel upper. Ordered it last Sunday and it was delivered on Friday so they get points for pretty quick shipping. It , the scope and mount were well packed. One gouge that was almost through the outer box made me appreciate the fact that it was double boxed with decent egg crate foam in the inner box. Appearance wise the anodizing on the upper receiver and the free float handguard matched well. Also matched and locked up tight on the PSA I have from a previous build.
Cleaning and closer inspection picked up a couple of minor problems. First off it was as dry as an old bone. No biggie. Looking at the gas block I noticed the adjustment screw access was blocked by the handguard. Also noticed that the end of the gas tube was slightly aft of the middle of the cam pin cut out. That made me wonder about the gas block location.
Removing the handguard was easier than it should have been. No sign of any locktite on anything. Another member had mentioned that he had a problem removing the smaller allen screws from his upper so I removed the two smaller screws first and then the three larger ones. All backed out too easily for my taste. The second of the smaller screws gave a tiny ping when it broke free but wasn't much past finger tight really. With the handguard off it was apparent that gas block was jammed hard against the shoulder of the journal.
Removing the gas block set screws was once again a bit easier than it should have been. Measured and marked gas port location . Backed off the adjustment screw all the way and verified gas block location by blowing through muzzle with breech plugged. Seemed to have minimal resistance so i called it good. After the adjustment screw was started I found 8 1/2 turns from fully closed to wide open. Just playing with the adjustment screw I didn't find much difference in air flow between backing it out to six to eight turns. Four turns out from fully closed seems about right so that is what it is set at for now.
Cleaned and lubed everything and reassembled. Noticed that bolt and carrier would not lock up unless charging handle was pulled fully aft and let go. Fully cycled it by hand thirty or forty times and it seems to seat much easier now.
Haven't mounted the Strike Eagle yet but just playing with it the eyebox is pretty small once you get past 6x. I'm hoping that a decent cheek weld will help that after it is mounted. Vortex mount seems kind of heavy for what it is. Think I will use my Larue Lt204 instead.
Still waiting for a couple of cases Barnhaul from lg-outdoors. It was supposed to be delivered on Friday but hasn't shown up yet. Range report to follow in a week or so.
All in all for $499 shipped with optic and mount I'm pleased so far.
Cleaning and closer inspection picked up a couple of minor problems. First off it was as dry as an old bone. No biggie. Looking at the gas block I noticed the adjustment screw access was blocked by the handguard. Also noticed that the end of the gas tube was slightly aft of the middle of the cam pin cut out. That made me wonder about the gas block location.
Removing the handguard was easier than it should have been. No sign of any locktite on anything. Another member had mentioned that he had a problem removing the smaller allen screws from his upper so I removed the two smaller screws first and then the three larger ones. All backed out too easily for my taste. The second of the smaller screws gave a tiny ping when it broke free but wasn't much past finger tight really. With the handguard off it was apparent that gas block was jammed hard against the shoulder of the journal.
Removing the gas block set screws was once again a bit easier than it should have been. Measured and marked gas port location . Backed off the adjustment screw all the way and verified gas block location by blowing through muzzle with breech plugged. Seemed to have minimal resistance so i called it good. After the adjustment screw was started I found 8 1/2 turns from fully closed to wide open. Just playing with the adjustment screw I didn't find much difference in air flow between backing it out to six to eight turns. Four turns out from fully closed seems about right so that is what it is set at for now.
Cleaned and lubed everything and reassembled. Noticed that bolt and carrier would not lock up unless charging handle was pulled fully aft and let go. Fully cycled it by hand thirty or forty times and it seems to seat much easier now.
Haven't mounted the Strike Eagle yet but just playing with it the eyebox is pretty small once you get past 6x. I'm hoping that a decent cheek weld will help that after it is mounted. Vortex mount seems kind of heavy for what it is. Think I will use my Larue Lt204 instead.
Still waiting for a couple of cases Barnhaul from lg-outdoors. It was supposed to be delivered on Friday but hasn't shown up yet. Range report to follow in a week or so.
All in all for $499 shipped with optic and mount I'm pleased so far.
