AR Sponsor
Joined:
Jul 2023
Posts:
261
EE: 100% (2)
MO, USA
Posted: 3/7/2026 1:39:59 PM EDT
[Last Edit: TheShootingAnvil][Edited]
| Like the title says, I'm looking to build a 300 Blackout SBR (ultimately suppressed) for a dedicated home defense setup. I'm not looking for anything top tier, but it needs to be reliable. It's been probably 10 years since I've built an AR. Back then, my go-to was Aero Precision, but from everything I read now the company has gone down the drain, non-existent customer service, varying degrees of QC on products, long shipping times, very little in-stock inventory, etc. So I'm not really sure what brands to consider now. Do I build my own? Do I consider a PSA upper and lower kit? Do I look at other big name brand guns? I'm not really sure what the best course of action would be. Interested in hearing thoughts and opinions of others here. Thanks! |
|
I bought a DD but in hindsight that was dumb as only the bolt carrier and upper/lower are still DD. I'd do a PSA receiver set, a Seekins Precision 8.3" barrel, a G SSA-E trigger, an LMT bolt, and reliable carrier, and your rail and optic if choice. You could probably swap out the barrel for anything you'd like just make sure you test the threads for concentricity and test it for overall reliability. Seekins is top tier stuff and I've never heard of a bad Seekins barrel so I'd say spend your money on the barrel, the trigger, and the bolt, as those are the things most likely to go sideways if the quality is a bit off. Get a decent optic. Holosun, Trijicon, Aimpoint, etc. |
|
Check out https://bkingsfirearms.com/product-category/ar15-barrels-223-wylde-5-56mm-300-blk-and-6-5-grendel/?wpf_filter_barrel-caliber=300-blackout-barrel&wpf_fbv=1 Their house barrels are likely Ballistic Advantage. My pinned 9" has been great. I have also been impressed with the Rosco 8.2" Bloodline 300 blackout barrels. Primary Arms has them on sale right now. |
|
Unfortunately, Aero is about toast. Staying in WA probably killed them. As far as 300blk, it is no different than 5.56 decisions. Grabbing something fully assembled is fine, or build it yourself with a decent barrel and bolt. Either works. One plus is that you will not need to chase sub MOA. One minus is that they are harder to tune. I currently have a 9" Ballistic Advantage Performance series. (no longer made) for HD. But I'm going to drop down to an 8" Wilson Combat, just to save an inch and some weight. It was that or an 8.2" Rosco (or 8.3" BA Hanson, but the WC was by far the lightest). On a side note: Those BA Performance series were neat. They were the "Modern" series cuts, but set up like the Hanson's with the NB feed ramps and being both HP and MPI tested. https://www.ballisticadvantage.com/9-300-blackout-pistol-length-ar-15-barrel-performance-series.html  Modern  Hanson  |
|
I don't think the upper/lower receivers are going to be a make or break issue with reliability. As mention in-spec PSA should be fine. I would opt for one of the blem BCM stripped uppers, just be aware they are thermal fit and can be really tight with some barrels. A couple of things to be aware of, in my experience the short barrel (7"-8") struggle with reliably cycling subs when shooting unsuppressed. Mine cycle supers just fine without suppressors but not enough gas/backpressure to cycle without the suppressor. As far as barrels get a known quality barrel that fits your budget and expectations. I have a DD 10.3" that cycles 220gr subs fine without the suppressor. I have Q honey badger barrel and a Faxon 7.5" 1-5t that will not reliably cycle the Hornady black 208gr AMax even with the suppressor, I cannot get enough gas and even drilled out the port in the Faxon in an effort to get it to reliably cycle. I have not found any 220gr subs that won't run in either barrel. I also have an 8" Rainier Select that runs everything fine suppressed, including the 208gr AMax. My brother runs an 8" (maybe 8.3") BA barrel that seems to run everything fine using a Griffin dual-lok 7 suppressor. I am using adjustable gas blocks but generally run them wide open for subs and adjust a couple setups for super only, it is just too big of a pain in the ass to continue adjusting. I have used everything from budget PSA adjustable blocks and the PSA click type adjustable to SA and the honey badger adjustable block. No real difference in them after adjusted. The Riflespeed blocks may be the ticket for simple adjustability but I haven't used them so have no real feedback. Solid BCG and bolt, barrel that meets expectations. Receivers, handguard, trigger, LPK, etc. of your choice and you should be fine. Depending on legality in your AO, budget in an FRT. |
Joined:
Jul 2023
Posts:
262
EE: 100% (2)
MO, USA
|
Not a build, but I picked up a 9" BCM .300 BO complete upper and this thing is awesome. Gassed very well to run both suppressed and unsuppressed. I initially bought just the upper with the plan to throw it on the lower I run for my 11.5" 5.56. But I liked it so much I went ahead and bought a BCM complete blem lower for it. 
|
|
Originally Posted By panthermark: Unfortunately, Aero is about toast. Staying in WA probably killed them. As far as 300blk, it is no different than 5.56 decisions. Grabbing something fully assembled is fine, or build it yourself with a decent barrel and bolt. Either works. One plus is that you will not need to chase sub MOA. One minus is that they are harder to tune. I currently have a 9" Ballistic Advantage Performance series. (no longer made) for HD. But I'm going to drop down to an 8" Wilson Combat, just to save an inch and some weight. It was that or an 8.2" Rosco (or 8.3" BA Hanson, but the WC was by far the lightest). On a side note: Those BA Performance series were neat. They were the "Modern" series cuts, but set up like the Hanson's with the NB feed ramps and being both HP and MPI tested. https://www.ballisticadvantage.com/9-300-blackout-pistol-length-ar-15-barrel-performance-series.html https://www.ballisticadvantage.com/media/catalog/product/cache/5adadb4029f9adc51023e5ffd10c0dd4/9/i/9in_300blk_performance_1_1.jpg Modern https://www.ballisticadvantage.com/media/catalog/product/cache/5adadb4029f9adc51023e5ffd10c0dd4/9/i/9in_300_blk_modern.jpg Hanson https://www.ballisticadvantage.com/media/catalog/product/cache/5adadb4029f9adc51023e5ffd10c0dd4/8/_/8.3in_300blk_hanson_performance_1.jpg You guys are probably sick of seeing mine, but once again it's relevant to the conversation. Most of the parts were expensive on this build, but I went with the Hanson 8.3" barrel from BA and it's been great. I don't think BA barrels generally last as long as some of the more expensive offerings, but like OP's stated mission, this one is for HD and is zeroed/loaded with Barnes 110 Tac Tx. All that to say, I'm not putting ridiculous amounts of rounds through it and the barrel will probably outlive me. 
|
|
I've had good luck with a 10.5" Faxon Gunner barrel. It's more than accurate enough. Toolcraft BCG, take your pick of uppers and lowers. Other parts are so subjective I won't bother. I use the Magpul .300 specific mags. Ditched all of my other Pmags for easy identification, and use mag bands for double measure. In hindsight I would probably buy Lancers for the .300 and keep my other Pmags, but as it is I use only steel or alum mags in my 5.56 guns now. My .300 ammo goes into clearly marked and separately stored ammo cans. Keep that shit separate if you have 5.56/.223 caliber AR's. |
My current project. I have the last two Railscales showing up tomorrow. I’m going to make sure this thing runs before I order a light from Arisaka. Hopefully I can hit the range Friday or early next week.  Bad Attitude Department PSR clear anodized receiver set Magpul ejection port cover Forward Controls Design forward assist Ridgeback Defense Sahara 300 can with LMT Ti Regulator Xeno mount Geissele SSA-E X trigger Armaspec anti-walk pins HK ambi bolt release AS Designs 0-90-180 Arc Fire V2 B5 Systems P23 grip and Bravo stock BCM 7” MCMR rail Railscales Terracore G10 MiniDot scales Phase 5 stubby grip Sentry charging handle Forward Controls Design sling mount Fortis Mfg K1 contractor castle nut and end plate 8” Geissele barrel with the phased array gas system Geissele bolt carrier group Geisseke Super 42 buffer springs and H3 buffer Geisselle buffer tube Geissele Ultra Duty lower parts kit Holosun 509T X2 green dot American Defense Manufacturing cowitness mount I snatched up a bunch of the stuff from the various 4th of July sales. I have taken to putting the rubber mag ID bands on my 300 BO mags. Any mag with a band on it is a BO mag. Two dozen of them are about $17.00 shipped. |
|
Mine is 7" barrel with a compact uciw stock. Kac urx4 8.5" handguard. Omega 9k can. For me it's the perfect HD setup. Attached File |
|
Get a Superlative Arms gas block and set it in restrict mode to just lock back usung unsuppressed supers and suppressed subs. Deal with the tiny over gas from suppressed supers. Use a carbine 3oz buffer and JP polished carbine spring. Use a regular M16 bolt and carrier in your preferred finish. No titanium or aluminum carrier. No NiBor bolt/extractor. No nitrided bolt. Use a high back pressure can if you care about quiet subs. Don't go over 11.5" or under 8.5" barrel length. Use pistol gas. |
AR Sponsor