OP
OP
GBExpat
Member
Quick update ...
I found some time to re-assemble (to the appropriate project point level) those two Faxon-barreled Uppers and, a couple of hours ago, fired 5/ea of the same Lot of ammunition thru them.
The ejected cases look unremarkable ... just as they should have the first time I did this testing.
Upon inspecting the cases I did notice a couple of things of interest to me.
The 20" sports a regular gas block (GB) and the 16", an adjustable gas block (AGB).
The cases from the 20" (rifle-length gas) are well-marked by the extractor and each has a tiny ding from impact with the case deflector.
The cases from the 16" (mid-length gas) are much less marked by the extractor and exhibit no case deflector dings.
Utilizing SWAG methodology, I had set the AGB on the 16" to a lower-gas position hoping to get it close to the point where it would successfully operate but not quite manage to lock back the bolt after the last shot ... and I got very lucky. All 5 fired & ejected but the bolt was not locked back.
I plan on opening it in ¼-turn steps until I decide it is right.
Next step ... see if the FFHanguard on the 20", like the 16", will require modification for the AGB and make a plan to accomplish the mods prior to installing the AGB.
I found some time to re-assemble (to the appropriate project point level) those two Faxon-barreled Uppers and, a couple of hours ago, fired 5/ea of the same Lot of ammunition thru them.
The ejected cases look unremarkable ... just as they should have the first time I did this testing.
Upon inspecting the cases I did notice a couple of things of interest to me.
The 20" sports a regular gas block (GB) and the 16", an adjustable gas block (AGB).
The cases from the 20" (rifle-length gas) are well-marked by the extractor and each has a tiny ding from impact with the case deflector.
The cases from the 16" (mid-length gas) are much less marked by the extractor and exhibit no case deflector dings.
Utilizing SWAG methodology, I had set the AGB on the 16" to a lower-gas position hoping to get it close to the point where it would successfully operate but not quite manage to lock back the bolt after the last shot ... and I got very lucky. All 5 fired & ejected but the bolt was not locked back.
I plan on opening it in ¼-turn steps until I decide it is right.Next step ... see if the FFHanguard on the 20", like the 16", will require modification for the AGB and make a plan to accomplish the mods prior to installing the AGB.
