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300 blackout upper
- Thread starter dayman
- Start date
ingEneer22
New member
AAC makes great 300 BLK uppers. Quality parts.
PSA , DD, Stag, etc., etc....most of the manufacturers/ assemblers offer 300 BO uppers. I build my own as I very much like the caliber for Supersonic shooting, I am not into suppressed fire but that is the reason for development of the cartridge. Check Shotgun News they list mostly entry level (Model 1 Sales, m&A, etc) also BCM usually has an ad. Brownells and Midway list complete uppers or parts to build your own. CMMG makes super barrels and complete uppers/ rifles if memory serves me correctly. Stick with brands with good customer relations.
Brotherbadger
New member
For the price, SOTA arms makes a good 300 BO upper.
One thing to look at regardless of barrel length is gas port/system length. This cartridge functions best with a pistol length gas system. Even with the longer barrels 16"+.
If all you ever shoot is full power Supersonic ammo you can prob get by with a carbine length system. But if you are going to shoot Subsonics at all, save the headache and get a pistol gassed upper from the start.
AAC ( who brought this cartridge into the mainstream AR world) puts pistol gas systems into all its uppers. It works perfectly with all types of ammo.
If all you ever shoot is full power Supersonic ammo you can prob get by with a carbine length system. But if you are going to shoot Subsonics at all, save the headache and get a pistol gassed upper from the start.
AAC ( who brought this cartridge into the mainstream AR world) puts pistol gas systems into all its uppers. It works perfectly with all types of ammo.
Recently picked up a White River Armory 16 inch upper at the Tulsa Wanenmacher Gun Show at a low enough price point (sub $300) that I couldn't pass it up, as I had a complete lower and spare bolt carrier group at home not doing anything.
I hadn't really committed to a brand/manufacturer yet and the the price point was much lower than my research had led me to look for up to that point. So it seemed like a good opportunity to look at the cartridge and play around with it from a relatively inexpensive price point.
The upper's specs are as follows:
• 16" length Heavy Barrel
• 4150 Chromemoly vanadium barrel with Black Nitride (Melonite) Finish
• Carbine Length Gas System
• .300 AAC Blackout Chamber
• 1 in 7" twist rate
• M4 Feed ramps
• Picatinny Railed Front Gas Block .750 diameter under gas block
• A2 Flash Hider 5/8 - 24 Thread
• Carbine Hand Guards w/ heat shields
• Forged upper receiver
• Does Not include Bolt Carrier or Charging Handle
• Made in the USA
The outfit was pretty low key and they were difficult to find on the web. I think an outfit called law-guns out of Indiana markets these for them.
Anyways, in early testing so far, it has performed flawlessly with supersonic Hornady 110gr Vmax, Remington 110 gr OTFB and FTW 150gr FMJ plinking ammo.
Subsonic Remington 230gr FMJ did not agree with it (might function fine for 4 to 5 shots then have problems cycling rounds). Both of the Remington rounds can be bought at Academy Sports here.
The dealer was straight up about the functioning issues with the subsonic Remingtion, so no surprises there. Sharkbite's post seems right on point based on my limited exposure to this round so far. If you are interested in subsonics at all definitely go with the pistol length gas system.
I hadn't really committed to a brand/manufacturer yet and the the price point was much lower than my research had led me to look for up to that point. So it seemed like a good opportunity to look at the cartridge and play around with it from a relatively inexpensive price point.
The upper's specs are as follows:
• 16" length Heavy Barrel
• 4150 Chromemoly vanadium barrel with Black Nitride (Melonite) Finish
• Carbine Length Gas System
• .300 AAC Blackout Chamber
• 1 in 7" twist rate
• M4 Feed ramps
• Picatinny Railed Front Gas Block .750 diameter under gas block
• A2 Flash Hider 5/8 - 24 Thread
• Carbine Hand Guards w/ heat shields
• Forged upper receiver
• Does Not include Bolt Carrier or Charging Handle
• Made in the USA
The outfit was pretty low key and they were difficult to find on the web. I think an outfit called law-guns out of Indiana markets these for them.
Anyways, in early testing so far, it has performed flawlessly with supersonic Hornady 110gr Vmax, Remington 110 gr OTFB and FTW 150gr FMJ plinking ammo.
Subsonic Remington 230gr FMJ did not agree with it (might function fine for 4 to 5 shots then have problems cycling rounds). Both of the Remington rounds can be bought at Academy Sports here.
The dealer was straight up about the functioning issues with the subsonic Remingtion, so no surprises there. Sharkbite's post seems right on point based on my limited exposure to this round so far. If you are interested in subsonics at all definitely go with the pistol length gas system.
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Shot mine today testing some new handloads. Hornady 110 spire points gave me 3 shots in one elongated hole @ 65 yards. These were starting loads. Possibly a slight increase in powder charge may make that even better. Barely supersonic 190-195 grain BTHP showed 1/2-3/4" 3 shot group and I'm sure that can be improved. I wasn't trying real hard- just doing load workup.
This is a home brewed upper using a low priced Red-X barrel. I'd have to say it's "good enough".
This is a home brewed upper using a low priced Red-X barrel. I'd have to say it's "good enough".