SBR lower

Preparedness Depot in Acworth, GA

AtlMedic

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i have been planning out my next several gun purchases. I think I want to go ahead and try and do a SBR sometime this year maybe.

As far as lowers go what do I need to look for to have the most versatile lower possible. I think primarily it would end up with a 9mm upper. Do I need to have anything specific in the lower to make that work?
 

dial1911

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You can use a conversion block with any standard AR lower (PSA has one- so do some others like quarter circle ten; actually I think QCTen has their own full lower).

I did this one my AR9. Then I bought a glock mag lower from Dog Leg Arms, because I have Glock mags and didn't want to spend $30ish each on the PSA mags (I've heard you can get converted UZI mags and Colt mags for cheaper, but damn if I can find them).

The New Frontier Armory glock mag lower is really nice- takes most of the standard parts from a LPK and as the name implies, uses Glock 9mm magazines.

Only drawback here is if you go with the glock mag lower, that's the only caliber you'll be shooting out of the SBR.

Oh- and to install/remove the adapter block in a standard AR lower, you have to remove the bolt hold open lever on the left side.
 
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Strider12

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You can use a conversion block with any standard AR lower (PSA has one- so do some others like quarter circle ten; actually I think QCTen has their own full lower).

I did this one my AR9. Then I bought a glock mag lower from Dog Leg Arms, because I have Glock mags and didn't want to spend $30ish each on the PSA mags (I've heard you can get converted UZI mags and Colt mags for cheaper, but damn if I can find them).

The New Frontier Armory glock mag lower is really nice- takes most of the standard parts from a LPK and as the name implies, uses Glock 9mm magazines.

Only drawback here is if you go with the glock mag lower, that's the only caliber you'll be shooting out of the SBR.

Oh- and to install/remove the adapter block in a standard AR lower, you have to remove the bolt hold open lever on the left side.
http://shop.lcjwholesalestore.com/D...48B95BF0891BC074D009E7E4881D2B.m1plqscsfapp06

Haven't had a single issue with these mags and like them better than the PSA ones.
 

Red Dawn

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I've heard the conversion blocks are so snug once they've been set its best to leave it as to not damage anything trying to remove it.
 

dial1911

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I've heard the conversion blocks are so snug once they've been set its best to leave it as to not damage anything trying to remove it.


Oh- I forgot... some people install set screws through the sides of the AR lower mag well- by drilling and tapping holes in the lower.

I didn't do that with the PSA block. I just dropped it in (with the bolt catch removed). It rattles like a bitch, but feeds fine. Surprisingly.
 
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Red Dawn

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And aren't the PSA 9mm AR married to each other. If you get the PSA upper it only fits/works with the PSA lower. I think I saw that somewhere here maybe.
 

dial1911

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And aren't the PSA 9mm AR married to each other. If you get the PSA upper it only fits/works with the PSA lower. I think I saw that somewhere here maybe.

Don't know- maybe true for their new Glock mag lowers. The New Frontier lower recommends using their upper only- there's no bolt hold open on the lower if I'm remembering correctly- it's on their Upper.
 
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boss_hawg

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get the hahn precision bottom loading mag block.

then you don't have to remove the bolt catch to change from 9mm to 556/300/762/etc.
 
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NWS

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get the hahn precision bottom loading mag block.

then you don't have to remove the bolt catch to change from 9mm to 556/300/762/etc.


This is the answer you are looking for. I have a bottom loading Hahn and it has been moved from lower to lower over the years. Never an issue. I personally would never SBR a dedicated lower. I like leaving my options open.
 
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Laufen

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Or get a Scorpion Evo3 for about the same price as building a PSA 9mm and be done with it.
 

Strider12

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Or get a Scorpion Evo3 for about the same price as building a PSA 9mm and be done with it.
And have a one dimensional weapon. At least with the lower you can shoot multiple calibers. I learned my lesson about SBRing a pistol.
 

AtlMedic

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I'm really tempted to just go ahead and save my pennies toward the new frontier lower. I just love the idea of a Glock mag fed SBR.

But I do hate the idea of limiting myself.
 
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boss_hawg

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my 9mm sbr AR pulls double duty with a 10.5" 556 upper. the hanh "power bottom" block - though expensive for what it is - makes that possible.

I got burned by cheaper, shittier mag blocks (or block). I went straight from a failure-inducing promag straight to hahn. it always works. dont be a cheap ass and buy a non-functioning part - it's not worth it no matter what the cost.
 

Strider12

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my 9mm sbr AR pulls double duty with a 10.5" 556 upper. the hanh "power bottom" block - though expensive for what it is - makes that possible.

I got burned by cheaper, shittier mag blocks (or block). I went straight from a failure-inducing promag straight to hahn. it always works. dont be a cheap ass and buy a non-functioning part - it's not worth it no matter what the cost.
Fucking power bottom!
 

dial1911

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