I couldn't find any buying/recommendation thread so I made this one.
Considering about buying an AR-15 SBR, since there are no restrictions on barrel lengths where I live. The ones I have in mind all use a short-stroke gas piston system like the HK416 or FN Scar, so malfunctions due to heat, pressure, dirt or gas are my least concern.
What I'm more interested in, is barrel length since I couldn't find any reliable and consistent source on barrel lengths. What is the perfect size for a rifle/carbine used for shooting targets from 20m - 50m up to 300m, perfect for prepping or SHTF/survival situations and easy to carry and use inside buildings or CQB situations in general. It also should be easy to carry in a backpack, possibly lower and upper separated if I have to go somewhere where people shouldn't see that I carry a carbine with me. I have the option of a 16", 14,5", 12,5" and a 10" barrel.
I'm mostly interested in a 14,5" or 12,5" barrel, since I already have a SIG 550 with a 20" barrel and I heard that anything below 12,5" is useless for a range above 50m. What do.
Somebody can correct me on this, but the big cutoff for 5.56 is at the 12-14 inch range where you lose a lot of FPS in unused powder burn. I think Wolf imports a 14 inch T91 upper, I got a 16 inch that I plan to build when it gets here. Were you thinking suppressed?
Gabriel Nguyen
Thanks for your answer. I read that with a 12.5" barrel it'll loose about 400fps compared to a 20", but some people told me it's insignificant up to 300m. No I don't intend to attach a suppresor because I'd need permit for it and the AR-15s in questions don't have a threaded barrel I think, because they are civilian models based on the HK416. All they have is a flash hider that is part of the rifle.
Chase Morris
Shamefully bumping this up.
Henry Jackson
forth attempt
Jonathan Evans
Christ, dude. You don't have to bump that much. Zig Forums is relatively slow.
I think it's more like 11 inches, but largely you're correct. There's a very steep drop off around that area due mostly to unburned powder. OP, I'd hesitantly say your best is the 14.5" barrel, at least with 5.56. If you want a dedicated doorkicker carbine that's even shorter, I'd suggest going for .300 memeout or some other caliber that's less velocity-dependent than 5.56.
Zachary Evans
Let's make this the AR thread since there isn't one Current impending build: My only issue is it seems the pin that holds the hammer is loose, as in falls out if tapped loose, while the hammer is cocked. It's self contained so I'm not worried about it too much, but I'd prefer if the little faggot would stay in its hole. Any recommendations?
Cameron Torres
Hammer/trigger pins are dirt cheap from Brownells or your FLGS, just get another set (or a set of anti-walk pins) and see if it fixes the problem. If not, it may be that Poverty Pony's QC department screwed you and the holes for your hammer/trigger pins are just the tiniest bit bigger than they're supposed to be.
Landon Morris
I've heard about this bullshit before. I'm expecting more pins in the Brownells kit, if that doesn't fix it i'll get a set of KNS pins that long on eachother. Oh well, problem.
Jackson Clark
This is false. It may not be optimal but it doesn't warrant poor performance. At these short barrel lengths performance becomes close to the .221 fireball and .221 fireball is good out to about 200 yards with 300 pushing it. Although you will have more muzzle flash and recoil then the fireball.
Ryder Price
*Lock on eachother. I've made a retard of myself on the internet
Brayden Foster
Go with 14.5. That's the best supported ammo wise.
Ryan Morgan
The question is not whether you can punch paper at that distance but whether 223 still has it's characteristic self destructing properties at that distance or whether it just punches through. 20" gives you that behavior all the way out to 300m, while 14.5" is considerably less and 10.5" keeps the required velocity for about 30m or so. If only I could find the like to the study. Someone wrote a formal paper on this. Anyhow, past the 2500 fps drop off point, 223 turns in to a varmint round. 20" gives you about 2920 fps, 14.5" nets 2700-something. Hence, with an AR15 you want the longest practical barrel.
Jace Rodriguez
Thank you all for your answers. I've found this chart recently but it isn't really helpful since it doesn't mention distance, ammo used or similar. I've come across several forum posts which all claim different things. But considering that most carbines are 14,5" I'd say this is the best I'd get, although I really prefer a 12,5" barrel.
The red line means fragmentation, so everything over it means that the bullet will fragment at by the speed it has in the barrel.
Henry Gonzalez
Don't use 5.56 if you want a shorter barrel. Suffers from performance issues. You could try chambering it in a hotter pistol calibre or find a different cartridge that works better without as much barrel length. I think 5.45 is a good choice, but I don't know how much aftermarket support there is for using it in an AR platform. Might be worth just getting a krinkov meme machine, 300 blabout could work as well.
It's crap out of a short barrel - see the AKS-74u. 75 meters is when practical accuracy goes out the window.
Brayden Phillips
I was thinking about 5.45 and 300BLk too, but 300 Blackout is very expensive and 5.45 is very rare here. 7.62x39 is cheaper and more available but you still pay a lot of money for it, otherwise I'd have taken an AK-47.
Adam Davis
Look up the ballistics of 7.62x39, really not a good choice. If you want a larger diameter bullet then just move on up to .308 nato out of a para FAL or something
Not really interested in the ballistics of an AK-47, I want one for prepping/survival/SHTF reasons. I'm aware that the AK wasn't designed with that in mind.
Ian Martin
20" only
Jonathan Green
You must be trolling.
Nicholas Hill
Then soft points are the way to go. They don't fragment but they will still give decent wounding down to lower velocities. And there are plenty of loadings to choose from.
A 10" barrel has a muzzle velocity of 2616 fps for a 55gr FMJ.
We get a ballistic arc that looks effective to 200 yards then drops quickly after that, but still remains supersonic out to 500 yards ( i.e. above 1125fps ).
How much fps does it need to still be considered lethal.
Landon Reyes
Well OP, I believe your problem is that you want an SBR in 5.56.
On the one hand, 5.56 is great in a SHTF situation as it is plentiful and versatile, useful for shooting peeps and hunting small game.
On the other hand, an SBR is a very purpose-built weapon designed for relatively short-range engagements, sacrificing muzzle velocity and range for agility and being cool-looking.
OP, you want to diversify. Build a solid mid-length rifle in 5.56 that you will use 90% of the time, then go ahead and get a 300 blackout upper and keep a few dedicated magazines for when you need to use it.
Generally speaking fragmentation occurs over 2000fps per FBI Training Unit tests.
I do see a 2500fps figure as well; not sure where that one comes from.
Bentley Diaz
The good news is with 14.5" barrels you can just pin your 1.5"+ muzzle device on and not have to do SBR paperwork or give the ATF jew 200 bucks.
Xavier Diaz
Why even bother with a SBR when the current generation of pistol braces are essentially stocks? Something like the SBA3 is better than many actual stocks.
Around 12 inches is the sweet spot for 5.56 barrel length if you're interested in making the barrel as short as possible while maintaining the largest range of effective operation.
The 10.3/10.5s barrel lengths are common enough to be supported by a wide range of quality manufacturers, but unless you absolutely need the 2 inch length reduction there's no real reason to use them over a 12.5. There's just too much inefficiency here, commonly used powder loads in 5.56 just aren't designed to be fully effective with such a short barrel. You still have terminal effectiveness past 300m, but you're running the system right at the edge of efficacy.
14.5 is another option to avoid the ATF shenanigans by having your muzzle device pinned and welded. A permanently fixed muzzle device is a pain in the ass though unless you're absolutely certain you're going the leave the carbine alone for the rest of it's life.
Isaiah Collins
It depends on the muzzle device. You can get 14.5" barrels with a factory-pinned flash hider that are designed to be slim enough to slip gas blocks over them without any trouble.
As I already said, there is no barrel length restrictions here. You can have a 24" or a 9", doesn't matter. I just want a SBR in 5.56 that is lethal up to 300m with the shortest barrel possible and that seems to be 14,5".
Robert Peterson
Why don't the side guns have triggers? Is this thin full auto?
Asher Morgan
I imagine so, it would explain the crossed gas tubes.
Thomas Ortiz
Uh.. Maybe try the M1? CMP is still selling them.
Carter Bennett
Where do you live to be able to buy a SIG 550?
Also since you want to be able to engage a target with 5.56 at 300m with the smallest barrel to do the job. Why not look into getting a bullpup? Still have the compact-like size of a SBR.
I thought about this but all we have here is the IWI Tavor, IWI X95 and Steyr AUG and the Tavor would eat up my whole budget and I can't put much on the Steyr AUG Z except a scope and magazines for it are very hard to come by.
Chase Williams
They make an AUG that takes STANAG mags called the "AUG NATO" or something like that, do they sell that model over there?
Thomas Morgan
Oh, and I forgot, what about the F2000? Or is that not sold there either? Sage for double post
Connor Ortiz
Yes there is, but from what I could gather it's the same thing with the G36. There are versions that accept NATO mags, but extremely rare on the civilian market because they are mostly made for export to countries that don't want to adopt their OEM mags. However there are conversion kits for the AUG to accept stanag mags, but wish me luck getting my hands on one.
So far I haven't found one and if I wanted I'd have to import one, which is very complicated and time consuming, even through a firearms dealer. Besides that the F2000 isn't really famous, even in the US, the F2000 has sold so terribly that FNH pulled it from the market very quick, the bullpup market there is in the strong grip of its greatest ally and their national firearms manufacturer IWI
All three Tavor, AUG and F2000 are also very expensive here and I intend on buying more than one gun, because it will probably be the last time I'll be able to after the whole debacle of the EU forcing their gun laws unto us. I'm going to buy basically a HK 416 semi-auto with a 14.5" barrel.
But still thanks for your answer
Ryder Cooper
Wait, that shit actually got through?
Nathan Smith
I'm surprised as well, Swissbro. How do they manage that when you're not even a part of the damn EU?
Ian Hernandez
Since we agreed to the Dublin Regulation and are now part of the Schengen Area, we have to comply with certain EU policies and can't negotiate individual contracts for it, like we did in the past.
These laws are beyond sane. If you're not some sort of olympic sport shooter, licensed hunter or collecter of antique firearms, you're done and fucked, you can't own anything. A commom EU/Schengen database for gun owners, registering all your firearms and police inspections to see if you have them stored correctly are just some of the many things they demand.
Luckily we have refendums and people's initiave here in Switzerland, unique compared to most other countries that don't have a direct democracy, which basically means that the people can make the laws and decide which laws will be adopted and which not.
So several pro gun organisations here threaten to take the referendum if the federal council decides to accept the new EU regulations, which will be adopted in may 2019.
If the vote is succesful we can keep our law, but will probably be kicked out of the Schengen area, which is not relevant for us, because schengen only means open borders within the EU.
It's clear that a referendum will take place, but I don't really know how it will turn out and I'm not to optimistic about it.
And people still don't believe in the Hibernian conspiracy
RIP in peace Switzerland.
Parker Martin
that's the worst fucking part. I would have expected you guys to be in he EFTA but not EU, but this is like "switzerland, now with less autonomy"
Grayson Butler
I don't just believe in it, I have faith in it.
Jordan King
It's still beyond me that gun control has anything to do with open borders etc. But we're thinking about leaving Schengen since 2007, because unlike Germany or France it has very little use to us and costs us several millions per year.
