Ryan Sykes 0 Posted December 24, 2022 The gas block is pistol length but barrel is 16” and total build will be over 26 inches https://palmettostatearmory.com/psa-16-pistol-length-300aac-blackout-1-8-nitride13-5-lightweight-m-lok-upper-with-bcg-ch-mbus-sight-set-5165448559.html Quote Share this post Link to post Share on other sites
Displaced Texan 11,731 Posted December 24, 2022 Link shows 13.5” barrel. Are you building an ‘other’ firearm? Oops, never mind. That was the hand guard length. I don’t see why it wouldn’t be legal for a rifle build as long as the muzzle device is replaced with a brake or comp, and it’s pinned and welded. Quote Share this post Link to post Share on other sites
PK90 3,570 Posted December 24, 2022 The 26" OAL is irrelevant when building a rifle. Especially and AR, which adds an extra 14" with the receiver and extension. Quote Share this post Link to post Share on other sites
Ryan Sykes 0 Posted December 24, 2022 So is this legal in Jersey for a rifle . When i see pistol length gas block mentioned that’s what i need clarifying on before i buy this upper. @PK90 Quote Share this post Link to post Share on other sites
PK90 3,570 Posted December 24, 2022 Pistol Length here refers to the gas system. Most .300AAC rifles use the pistol length. ETA: Yes legal as mentioned above by the man from TX. Quote Share this post Link to post Share on other sites
Ryan Sykes 0 Posted December 24, 2022 Thank You guys Quote Share this post Link to post Share on other sites
My1stGlock 144 Posted December 24, 2022 Excuse my ignorance. Why would they use a pistol length gas block on a 16” barrel? I thought they were usually either carbine, mid length or rifle length for AR rifles? Wouldn't they have issues either short stroking or ejection issues? Quote Share this post Link to post Share on other sites
sgtdave4321 36 Posted December 24, 2022 I dont know too much about 300 black out, but I have read that they run well with the pistol lenght gas system. Quote Share this post Link to post Share on other sites
High Exposure 5,661 Posted December 24, 2022 5 hours ago, My1stGlock said: Excuse my ignorance. Why would they use a pistol length gas block on a 16” barrel? I thought they were usually either carbine, mid length or rifle length for AR rifles? Wouldn't they have issues either short stroking or ejection issues? The pistol length gas system is designed to run .300 ammo most reliably, especially subsonic offerings. These slow and heavy rounds need as much pressure in the system as possible to run reliably. You want the higher pressure of the shorter system to make sure all the moving parts move correctly (dwell). So basically, placing the gas port closer to the lower receiver allows more time for gas build up while the round travels down the bore. 1 Quote Share this post Link to post Share on other sites
Ryan Sykes 0 Posted December 24, 2022 @High Exposure can you run supersonic rounds through it too ? Quote Share this post Link to post Share on other sites
My1stGlock 144 Posted December 24, 2022 26 minutes ago, High Exposure said: The pistol length gas system is designed to run .300 subsonic ammo. These slow and heavy rounds need as much pressure in the system as possible to run reliably. You want the higher pressure of the shorter system to make sure all the moving parts move correctly (dwell). So basically, placing the gas port closer to the lower receiver allows more time for gas build up while the round travels down the bore. OK so specific to this round in the link. I usually hear about .223, 5.56, 7.62 x 39 and 300 blackout. Always learning! Quote Share this post Link to post Share on other sites
High Exposure 5,661 Posted December 25, 2022 1 hour ago, Ryan Sykes said: @High Exposure can you run supersonic rounds through it too ? I don’t have this upper, so I am not speaking from experience. I don’t know how reliable all super rounds will be, but I think you should be ok. The Pistol length gas system is a compromise between the myriad super and sub .300 offerings to offer the best reliability across the caliber. Quote Share this post Link to post Share on other sites
Ryan Sykes 0 Posted December 25, 2022 @High Exposure if you were to use the barrel for a build for a cqc home defense scenario would you use supersonic or subsonic rounds ? Quote Share this post Link to post Share on other sites
High Exposure 5,661 Posted December 25, 2022 55 minutes ago, Ryan Sykes said: @High Exposure if you were to use the barrel for a build for a cqc home defense scenario would you use supersonic or subsonic rounds ? I use 5.56/.223 for all social long-gun needs. I am not a .300 convert and am not 100% spun up on the ballistics. If I had a suppressor, I would use subs. If I didn’t, I would use supers. Quote Share this post Link to post Share on other sites
Displaced Texan 11,731 Posted December 25, 2022 19 hours ago, Ryan Sykes said: @High Exposure can you run supersonic rounds through it too ? You can run supersonic through this upper. It will probably be a bit over gassed. Quote Share this post Link to post Share on other sites
RUTGERS95 890 Posted January 1, 2023 On 12/24/2022 at 11:12 AM, Ryan Sykes said: The gas block is pistol length but barrel is 16” and total build will be over 26 inches https://palmettostatearmory.com/psa-16-pistol-length-300aac-blackout-1-8-nitride13-5-lightweight-m-lok-upper-with-bcg-ch-mbus-sight-set-5165448559.html totally legal Quote Share this post Link to post Share on other sites