Please Help- My 1st AR15 Pistol

Wyzrd

Harder than a coffin nail
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  • Feb 13, 2017
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    Cheyenne, Wyoming
    So, I’m not new to gas guns by any means, but I am new to AR15 pistols. I just bought a 10.5” Upper and already have a spare lower at home for it. My lower currently has a 6 position mil spec buffer tube on it with a Magpul CTR stock, and a JP SCS inside the buffer tube.

    My questions are:

    -Can I run a SBA3 pistol brace on a 6 position buffer tube, or do I have to buy a specific pistol length buffer tube?

    -What do you guys recommend to be the best/most comfortable pistol brace?

    -Can I run my JP SCS in a pistol build, or do I have to buy a specific buffer/spring set-up?


    -My Upper has an adjustable gas block, but do you guys recommend a specific buffer weight in a 10.5” pistol?

    Thanks ahead of time for any and all help you guys can provide, as I’m ignorant when it comes to AR15 pistols and the legalities of them.??
     
    It used to be 'once a rifle, always a rifle'. Then it wasn't. Then it maybe was. Then I quit keeping up and form1'd a few lowers so I don't care anymore.
     
    It used to be 'once a rifle, always a rifle'. Then it wasn't. Then it maybe was. Then I quit keeping up and form1'd a few lowers so I don't care anymore.

    I get it. All the various legalities of what’s good to go and what isn’t for an AR15 pistol is ridiculous. I wouldn’t mind designating one of my lowers as an SBR, but that’d be down the road still. So, til then I gotta figure out this whole pistol thing.
     
    -Can I run a SBA3 pistol brace on a 6 position buffer tube, or do I have to buy a specific pistol length buffer tube?

    I couldn't remember what it even has and I bought a whole lower. From the PSA website for a pistol kit:

    Also includes SB Tactical SBA3 Adjustable Pistol Brace, castle nut, latch plate, carbine buffer spring, 5 positioning mil-spec buffer tube, and standard carbine buffer.
     
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    I get it. All the various legalities of what’s good to go and what isn’t for an AR15 pistol is ridiculous. I wouldn’t mind designating one of my lowers as an SBR, but that’d be down the road still. So, til then I gotta figure out this whole pistol thing.

    What I meant was, converting a lower that is already a "rifle" (with a stock) to a "pistol" has always been a grey area I have avoided.

    I have always played by the "rule" that a lower can go from pistol to rifle but not rifle to pistol. Or if it was sold as a stripped 'receiver' then it can become either.
     
    What I meant was, converting a lower that is already a "rifle" (with a stock) to a "pistol" has always been a grey area I have avoided.

    I have always played by the "rule" that a lower can go from pistol to rifle but not rifle to pistol. Or if it was sold as a stripped 'receiver' then it can become either.

    I gotcha. Now, I’m not sure if this is true or not, but a guy that works at my local FFL was telling me that all I would need to do in order to switch from a rifle lower to a pistol lower; is to take off the stock, and just slap on a pistol brace. Don’t know if that’s true, but if so, that’s easy enough! As stupid as most of these gun laws are IMO, I just want to make sure I don’t break any of them.
     
    It depends on what it was listed as on your 4473 as I understand it. If it was a complete rifle when you bought it, then it's a rifle as far as the Feds are concerned.

    Whenever I buy a stripped lower, I have my FFL write it up as "Other" where you put the type of firearm it is. Then, if I build it as a pistol, I take the completed pistol back to my FFL to fill out the necessary paperwork for my county sheriff to register it.
     
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    As the others have said, it depends on the lower. If it was a stripped lower you can build either and go back and forth, so long as it’s never registered as a “rifle”.

    Also the SBA brace will work on the carbine receiver extension. I swapped mine out a few times. Same extensions has had 2 different braces and 3 stocks now (was a stripped lower, never registered)

    Also, I ran the Armaspec spring (very similar to the JP SCS) in my pistol and had no issues. That spring has been in 4 different builds now as well and functions perfectly from a pistol builds to 20” Grendel build.
     
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    As the others have said, it depends on the lower. If it was a stripped lower you can build either and go back and forth, so long as it’s never registered as a “rifle”.

    Also the SBA brace will work on the carbine receiver extension. I swapped mine out a few times. Same extensions has had 2 different braces and 3 stocks now (was a stripped lower, never registered)

    Also, I ran the Armaspec spring (very similar to the JP SCS) in my pistol and had no issues. That spring has been in 4 different builds now as well and functions perfectly from a pistol builds to 20” Grendel build.

    Sweet! To AMP! and everyone else that commented on this thread, I greatly appreciate the help!!!
     
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    I am at the shake-down stage of my first pistol build. It's a 10.3" 300 Blackout that will run suppressed 100% of the time.

    The SBA3 should work fine with your existing buffer tube. That said, I would also look at the new SBA4. I have the similar SBM4 that is not adjustable and get a really good cheek weld with it.

    It's hard to say is the JP buffer setup will work without knowing the gas system length, caliber, whether it will run suppressed, etc. Part of my shake down has been running various buffer weights to determine what will operate with 100% reliability. That said, they are all standard carbine buffer components. Nothing special for a pistol. Your mileage may vary since you have an adjustable block.

    As mentioned before, just make sure the lower was marked "other" on the 4473. Also, be aware of the opinions by the ATF on foregrips that can be installed on pistols depending on the overall length.

    IMG_0267.jpg
     
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    I am at the shake-down stage of my first pistol build. It's a 10.3" 300 Blackout that will run suppressed 100% of the time.

    The SBA3 should work fine with your existing buffer tube. That said, I would also look at the new SBA4. I have the similar SBM4 that is not adjustable and get a really good cheek weld with it.

    It's hard to say is the JP buffer setup will work without knowing the gas system length, caliber, whether it will run suppressed, etc. Part of my shake down has been running various buffer weights to determine what will operate with 100% reliability. That said, they are all standard carbine buffer components. Nothing special for a pistol. Your mileage may vary since you have an adjustable block.

    As mentioned before, just make sure the lower was marked "other" on the 4473. Also, be aware of the opinions by the ATF on foregrips that can be installed on pistols depending on the overall length.

    View attachment 7096300

    Sorry, should’ve added that info earlier... carbine gas, chambered in 5.56, and for now at least, I will not be running a can on it. Just gonna throw on a Lantac Dragon for the time being.
     
    So, I’m not new to gas guns by any means, but I am new to AR15 pistols. I just bought a 10.5” Upper and already have a spare lower at home for it. My lower currently has a 6 position mil spec buffer tube on it with a Magpul CTR stock, and a JP SCS inside the buffer tube.

    My questions are:

    -Can I run a SBA3 pistol brace on a 6 position buffer tube, or do I have to buy a specific pistol length buffer tube?

    Yes, standard carbine.
    -What do you guys recommend to be the best/most comfortable pistol brace?
    SBA3 or spend 5 minutes online doing a Form 1, wait a week to get approval and enjoy your new SBR without wasting money on a SBA 3.
    -Can I run my JP SCS in a pistol build, or do I have to buy a specific buffer/spring set-up?
    Hell yes, run it.
    -My Upper has an adjustable gas block, but do you guys recommend a specific buffer weight in a 10.5” pistol?
    JP SCS. The best available!
    Thanks ahead of time for any and all help you guys can provide, as I’m ignorant when it comes to AR15 pistols and the legalities of them.??
     
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    With a quality adjustable gas block you should be ok with the SCS, but I'd recommend going with an A5H2 or A5H3 setup on a 10.5in carbine if you can. And the SBA3 will still work on the A5 tube.
     
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    No legal advice

    The SBA3 fits a milspec buffer tube.

    Get the “split fix” from 3 wisemen to further assist the brace being a better brace...... firms it up really nice.
    After you mentioned this, I got curious. I now have one ordered up, hoping to get it this week. Looks like a good rig. Thanks for the heads up
     
    After you mentioned this, I got curious. I now have one ordered up, hoping to get it this week. Looks like a good rig. Thanks for the heads up
    Be careful modifying a brace. If you modify it it could be considered altering it into a rifle. ATF specifically states this. I don’t know anything about this product but if you are wedging something into the brace where your arm would go I would be very leery of that.
     
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    Agreed on modifications. The split fix appears to be a longer strap, made from a better quality material. I know I cant slip an arm through the factory one without messing with the strap coming out. It's not long enough, and made from cheap, bungee like, fabric.
     
    AR pistols are legally pistols and can be carried loaded and accessible in a vehicle, SBRs are rifles and have to be unloaded and not accessible in your vehicle. Also, you will need to submit, and get approved, a 5320.20 to legally take your SBR across state lines.

    OFG
     
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    Ok, as I stated, my interest was peaked. Here are my initial thoughts on the "split-fix":
    -tight squeeze getting it all looped through
    -quality material/stitching
    -eliminates the strap coming undone while trying to attach brace to wrist
    -makes for a better, and more secure fit, but DOES NOT, in any way, make it feel the least bit like a stock
    -it does help keep the rubber part formed properly, eliminating premature (so far) wear or breakdown/collapsing of the rubber
    -wish I could've got the desert camo, but the tan is still dope

    Just my thoughts for anyone interested. Again, I appreciate the recco, as the factory strap is a nuisance. And with a DIY desert camo build, that black strap doesnt fit the bill. Especially with its fraying, and cheap velcro.