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Posted: 1/17/2026 4:16:55 PM EDT
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I'm in the midst of putting together a shopping list for a 10.5 inch pistol build and I'm curious about the buffer assembly. Is it sufficient to use a Spike's lower marked "multi" to build this up or do I need a pistol marked lower. Also, can I just use one of the buffer tubes in my parts bin or am I required to use a smooth buffer tube? To boil it all down, if I buy a pistol parts kit from PSA (sans receiver) and one of their 10.5 inch uppers, am I within the rules? |
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Originally Posted By celticmarksman: I'm in the midst of putting together a shopping list for a 10.5 inch pistol build and I'm curious about the buffer assembly. Is it sufficient to use a Spike's lower marked "multi" to build this up or do I need a pistol marked lower. yes, as long as it wasn't transferred from the manufacturer as a rifle. which I don't think they do. Also, can I just use one of the buffer tubes in my parts bin or am I required to use a smooth buffer tube? yes. make sure you have a pistol brace on hand when it's going together. To boil it all down, if I buy a pistol parts kit from PSA (sans receiver) and one of their 10.5 inch uppers, am I within the rules? probably, that's how a lot of people do it. I'm not a lawyer and I never played one in a porno flick. |
The deuce you say.
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Originally Posted By celticmarksman: Two more questions; 1) Should I have a dedicated 300BO BCG 2) What is the hive's recommendations on the brace to get, I'm on a budget so be reasonable please :) |
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I don't own one and haven't even seen one in the wild, but others have. I am neither recommending them or disparaging them - you make up your own mind. https://www.ar15.com/forums/ar-15/Bear-Creek-Surprised-Me/121-792421/ https://www.ar15.com/forums/ar-15/1st-Time-out-with-Bear-Creek-450-Bushmaster-Upper/121-792454/ https://www.ar15.com/forums/ar-15/Bear-Creek-haters-ignore-this-20-CHF-upper-on-sale/12-792333/ . |
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Originally Posted By celticmarksman: So after pricing out the parts, it appears that I can buy a full pistol from Bear Creek for less than I can build one myself. Can anyone chime in on their quality? The price seems too good to be high quality. Any and all feedback is appreciated. Thanks I sent you an IM |
| They don't make dedicated 300 blackout BCGs. Standard 556 BCG and 300 blackout magazines. If you buy a lower that has rifle stock, it's a rifle.If you buy a lower that has a pistol stock, it's a pistol. SBA3 is a decent pistol brace and won't break the bank. Heavy or H2 buffer for use with subs. and supersonic ammo. |
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Originally Posted By celticmarksman: I am just wondering if I should have a dedicated BCG for any reason. I'm a little OCD like that....... Yes, but it is more like - "That upper should have a quality BCG". It isn't for 300blk, it is for that upper (regardless of cartridge). And as others have mentioned, 300blk uses 5.56 BCG's. |
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Originally Posted By celticmarksman: I am just wondering if I should have a dedicated BCG for any reason. I'm a little OCD like that....... Once you use that bolt carrier keep it with that upper,barrel And don't cheap out Bcm Toolcraft Black friday i picked up some nice blems |
1(800)kbi 4cat
Montani Semper Libre
Qoute : FCSD - Hold up! I could have tip toed around here with just my hand covering my ass, instead of jamming my thumb in my asshole? Y'all motherfuckers need a user manual or something.
Montani Semper Libre
Qoute : FCSD - Hold up! I could have tip toed around here with just my hand covering my ass, instead of jamming my thumb in my asshole? Y'all motherfuckers need a user manual or something.
| Good info posted so far. You don’t need a .300blk BCG so much as you should just keep one with the upper. As for BCA, they are hit or miss. I’ve had pretty good luck (I made one of the threads linked above), but I’m also pretty knowledgeable and I’m able to troubleshoot an AR if trouble arises. I also don’t rely on my BCA-10 to save my life. If you’re brand new to ARs and don’t know anyone knowledgeable, it could potentially be frustrating if you got a lemon from BCA. As for braces, the SBA3 is my preference, but my advice would be to just SBR it for free now. |
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Don't over complicate it. The only real different between a 5.56/300blk pistol and rifle lower is which piece of plastic you put on the end of your buffer tube. Just make sure the lower was never transferred as a rifle and you're fine. A stripped lower should just be transferred as "firearm" and be be built into a rifle or pistol. I like the SBA3 as a pistol brace. The only difference in the upper is going to be barrel length and fore grip. If you're barrel is less than 16.01", you need to have a pistol brace on the lower or register it as an SBR. You also can't use a vertical foregrip on a pistol or it becomes an unregistered AOW. The only different between a 5.56 AR and a 300blk AR is the barrel and the muzzle device (and arguably the magazines). Everything else is interchangeable. If you are going to own 300 blk and 556 firearms, just make sure you take special care to keep your ammo seperate 
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