Posted: 8/23/2015 10:54:02 PM EDT
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Anyone have a sub-14.5 inch precision AR? Dangerous thought popped into my head. Just curious if there are any NFA length precision barrels and what ammo is being used.
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The important thing to keep in mind is that precision does not equal long range. They aren't the same. Look at the guys dropping thousands of dollars into benchrest rimfire shooting to get out to 200 yrds. Super precise machines, but not made for long range. Same situation with a precision SBR AR-15. Sure, it's absolutely doable! Knock yourself out! |
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This is what I'm building at the moment. I went with a MicroMOA (Feddersen) 12.5" fluted barrel. MicroMOA is a site sponsor FWIW.
I'm looking for precision for 100-300 yards, although I'm sure a 12.5" bbl still has enough velocity to easily double that range. If I lived out west, it might be a different story. |
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Not something I've done myself, but the most important part is having a good barrel. A magnified optic helps but good groups can be shot without them. A magnified optic isn't something I ever mix with a short barrel Because of muzzle blast back at the glass? Or another reason? I'll have a magnified optic on mine, but the suppressor that will be living on it will make it about 20" total. |
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Quoted: Because of muzzle blast back at the glass? Or another reason? I'll have a magnified optic on mine, but the suppressor that will be living on it will make it about 20" total. Quoted: Quoted: Not something I've done myself, but the most important part is having a good barrel. A magnified optic helps but good groups can be shot without them. A magnified optic isn't something I ever mix with a short barrel Because of muzzle blast back at the glass? Or another reason? I'll have a magnified optic on mine, but the suppressor that will be living on it will make it about 20" total. Just personal preference. I use magnification for longer ranges which I typically use different guns. |
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Would you put a 20x on a 12.5"?   Quoted:
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Huh. I shot my fiancé's 16" out to 800 today. Interesting thing, I was comparing dope to a friends 20" and the thing apparently shoots just as fast and flat. For the record, I'd put a 10x optic on a short gun. Would you put a 20x on a 12.5"? Maybe for load development. It would definitely live with a 2.5-10 and a red dot, though. |
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Maybe for load development. It would definitely live with a 2.5-10 and a red dot, though. Quoted:
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Huh. I shot my fiancé's 16" out to 800 today. Interesting thing, I was comparing dope to a friends 20" and the thing apparently shoots just as fast and flat. For the record, I'd put a 10x optic on a short gun. Would you put a 20x on a 12.5"? Maybe for load development. It would definitely live with a 2.5-10 and a red dot, though. The way I see it, I have a 32x on a 16" Volquartsen .22lr bench gun that has never seen over a 100 yards. So why not a 20x for a 12.5" 5.56? |
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I built a "precision" sort of SBR for hunting coyotes where most shots are under 100yds and maybe the furthest out to 150-200yds but not likely. It's a stainless PSA 11.5" 1/7 twist bbl upper with Aero precision lightweight scope mount and Leupold VX-R 2-7x33 scope and illuminated LRV duplex. I haven't hunted with it yet but I was getting around 1.5-2" groups at 100yds using cheap 50gr tipped varmint Federal ammo without much effort. Not ideal for 1/7 twist bbl but they are devastating on coyotes.
This makes using my 9" 24oz Specwar 7.62 much more handier than on my 16" rifle. Obligatory pic (bottom gun) 
And my 10.5" 7.62x39 budget, short range pig thumper. Non-free float handguard shooting Tulammo from walmart at 100yds and a whopping 8x Lupy MKIV. I'm happy with it as well. 
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Huh. I shot my fiancé's 16" out to 800 today. Interesting thing, I was comparing dope to a friends 20" and the thing apparently shoots just as fast and flat. For the record, I'd put a 10x optic on a short gun. This was something I was trying to get across regarding 18" vs 16" barrels. The only difference is your dope, and where the bullet will go transonic. By that point, 5.56 might not be the best choice. I have a 12.5" DD Gov barrel that has zero issuss smacking steel at 500, not even a precision barrel. Something like a Noveske Crusader or White Oak 12.5" might group better, but the DD barrel gets it there. |
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This was something I was trying to get across regarding 18" vs 16" barrels. The only difference is your dope, and where the bullet will go transonic. By that point, 5.56 might not be the best choice. I have a 12.5" DD Gov barrel that has zero issuss smacking steel at 500, not even a precision barrel. Something like a Noveske Crusader or White Oak 12.5" might group better, but the DD barrel gets it there. Quoted:
Quoted:
Huh. I shot my fiancé's 16" out to 800 today. Interesting thing, I was comparing dope to a friends 20" and the thing apparently shoots just as fast and flat. For the record, I'd put a 10x optic on a short gun. This was something I was trying to get across regarding 18" vs 16" barrels. The only difference is your dope, and where the bullet will go transonic. By that point, 5.56 might not be the best choice. I have a 12.5" DD Gov barrel that has zero issuss smacking steel at 500, not even a precision barrel. Something like a Noveske Crusader or White Oak 12.5" might group better, but the DD barrel gets it there. It's still the best choice unless you're rocking a Creedmoor. |
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A 12.5" 6.5 Grendel changes things a bit, since BC's are so high and projo weight is substantial.
Run the numbers on a .510, .522 or .527 BC 123gr going 2300fps. You basically cut off 175yds of performance from a 24" Grendel. The 12.5" is still supersonic out past 875yds at sea level, using Litz G7 BC for 123gr SMK. At my altitude, the 12.5" Grendel keeps a 123gr supersonic past 1000yds. |
| I have been struggling to find a factory ammo/barrel combination that will allow me to achieve a consistent 1 MOA or better performance (at 100 yds) with a 10.5-11.5" barrel (5.56). Several manufacturers claim that their short barrels will shoot sub-MOA, but I have yet to see one that will do it consistently. |
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Quoted: The important thing to keep in mind is that precision does not equal long range. They aren't the same. Look at the guys dropping thousands of dollars into benchrest rimfire shooting to get out to 200 yrds. Super precise machines, but not made for long range. Same situation with a precision SBR AR-15. Sure, it's absolutely doable! Knock yourself out! |
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Quoted: I have a 14.5 jp barrel on my prairie dog gun with a zeiss 5 to 25 x 50 hd5 on it. Im limited to 300 yards at my house but at that range the gun is awesome. I have never understood why people think they need a 26" barrel As Jeremy Clarkson would say "Where's a hammer?" and "POWAAAAA!!!!". |
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When I broke in my new heavy contour 10.5" MG barrel I shot groups with it using FGMM 69gr. I was surprised when it shot at about 0.80 MOA. Not really precision, but good for such a loose and heavily shot gun. Im sure a good SBR could be a 0.5 MOA gun with a little work. |
Saw this post a few months back. Sorry I didn't reply sooner. 
I've had excellent luck "precision" shooting SBRs. I take great joy from doing it when people doubt it can be done. I do typically shoot them suppressed, so that often times negates the noise or little recoil. You do however have movement in your groups when doing that, as the short barrels tend to heat up. There have been naysayers who say this is not "accurate" because you can see real movement in your groups, however it's a very small amount, and your group size remains the same, it's simply the point of impact that changes In regards to ammo, I've had luck with my reloads, FGMM, and Norma Match. |
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My 10.5" SBR shoots 2" groups at 100 yards with wolf ammo. I've never even tried to shoot quality ammo out of it.
I imagine it would do a little better with decent ammo, so I would say precision out of a SBR is certainly something that could be accomplished. Just keep in mind that you will have a greatly reduced velocity so keeping that precision at greater and greater distances will prove to be very challenging. |
