HD AR Build

[23JAZ]

So I'm building my second AR. This will be a strictly HD/SD or anything inside 100 yards. What's the shortest barrel I should put on it. At some point I'm going to put a can on it and I want to keep the overall length as short as possible without loosing too much terminal performance.

[SamuelBLong]

10.5 / 11.5 will retain plenty of velocity & reliability. Anything shorter gets really finicky.

With a typical can length added on, you are looking at just short of a 16" gun.

This is a PWS Mk110 upper on an M16a1. Suppressor is a AAC 416-SD. Next to it is my patrol gun, a DDM4V1:


http://tapatalk.imageshack.com/v2/14/11/17/ff29694c9c8634f0168b8f39525d6244.jpg

[TGS]

So I'm building my second AR. This will be a strictly HD/SD or anything inside 100 yards. What's the shortest barrel I should put on it. At some point I'm going to put a can on it and I want to keep the overall length as short as possible without loosing too much terminal performance.

You didn't specify caliber.....so have you considered 300 Blackout?

[23JAZ]

You didn't specify caliber.....so have you considered 300 Blackout?
I was thinking 5.56 or 6.8. Never really considered 300.

[23JAZ]

10.5 / 11.5 will retain plenty of velocity & reliability. Anything shorter gets really finicky.

With a typical can length added on, you are looking at just short of a 16" gun.

This is a PWS Mk110 upper on an M16a1. Suppressor is a AAC 416-SD. Next to it is my patrol gun, a DDM4V1:


http://tapatalk.imageshack.com/v2/14/11/17/ff29694c9c8634f0168b8f39525d6244.jpg
That is beautiful. Thanks for the info!

[JodyH]

I'm a fan of 12.5" for a suppressed SBR.
With my AAC Ranger 2 on a 12.5" barrel it's exactly the same length as a 16" with a A2 flash hider.

I've found the 12.5" to be far easier to make run and keep running over a variety of ammo (both .223 and 5.56) and when the gun is hot and filthy.
The 12.5" will also run suppressed and unsuppressed without changing buffers, my 10.5" LMT required a H3 suppressed and a H2 unsuppressed.
You also get another 75 yards or so of effective range out of a 12.5" vs. a 10.5".

[Jason F]

I concur on 300BLK. I got to shoot a supressed SBR 300BLK on a recent visit to YHM and it was quite awesome. That's been on my radar for a while as a go to HD rifle, and it certainly cemented it as my next build and purpose for the build.

[Sigfan26]

I like 5.56 for home defense. With the right Ammunition ( read DocGKR's article) it works quite well. If you're looking for a home defense suppressor, take a long hard look at the Silencerco SakerK.

[LittleLebowski]

I'm a fan of 12.5" for a suppressed SBR.
With my AAC Ranger 2 on a 12.5" barrel it's exactly the same length as a 16" with a A2 flash hider.

I've found the 12.5" to be far easier to make run and keep running over a variety of ammo (both .223 and 5.56) and when the gun is hot and filthy.
The 12.5" will also run suppressed and unsuppressed without changing buffers, my 10.5" LMT required a H3 suppressed and a H2 unsuppressed.
You also get another 75 yards or so of effective range out of a 12.5" vs. a 10.5".

Why no 11.5"?

[JodyH]

I don't have enough time on a 11.5 to have an opinion either way.

[TGS]

I like 5.56 for home defense. With the right Ammunition ( read DocGKR's article) it works quite well.

I like 5.56 a lot as well, have a few, and have also read Doc's articles. But 100 and in, suppressed SBR? That's the 300 Blackout's calling card.

Barring free ammo, I really can't think of a reason to go with 5.56 over 300 BLK for that specific niche.

[23JAZ]

I like 5.56 a lot as well, have a few, and have also read Doc's articles. But 100 and in, suppressed SBR? That's the 300 Blackout's calling card.

Barring free ammo, I really can't think of a reason to go with 5.56 over 300 BLK for that specific niche.


I am leaning toward 5.56 because of the availability/price of that over 6.8 and 300 BLK. I don't reload and I tend to shoot a decent amount by my standards. (500 rounds a month of 5.56 and another 5-600 of 9mm) What about 7.62x39? Does anyone know how that does out of a canned AR?

[SamuelBLong]

Magazines are the weak point in the 7.62x39 in a standard lower AR system.


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[LittleLebowski]

I'd get a Sig 556R over a 7.62x39mm AR.

[rob_s]

I like 5.56 a lot as well, have a few, and have also read Doc's articles. But 100 and in, suppressed SBR? That's the 300 Blackout's calling card.

Barring free ammo, I really can't think of a reason to go with 5.56 over 300 BLK for that specific niche.

Funny, given that there is still no good "defensive" 300 subsonic ammo, I've come to the opposite conclusion that I can't think of a reason to go 300 BLK over 5.56 or, if I really want a gun that's subsonic and has ammo that performs well, 9mm.

[TGS]

Funny, given that there is still no good "defensive" 300 subsonic ammo, I've come to the opposite conclusion that I can't think of a reason to go 300 BLK over 5.56 or, if I really want a gun that's subsonic and has ammo that performs well, 9mm.

Because subsonic is the only ammo option for that caliber.... :rolleyes:

Funny.

[rob_s]

Because subsonic is the only ammo option for that caliber.... :rolleyes:

Funny.

What is the appeal of the non-subsonic? I can tell you that it's no quieter than a 5.56, suppressed or not, to the ear. Do you have evidence or documentation to support an idea that someone will me more-deader with the most-wonderful-of-wonder-projectiles than with the most-wonderful-of-wonder-projectiles in 5.56?

There's a reason the 300 BLK is called the "300 WTF" by a lot of people. The juice ain't worth the squeeze, and virtually all of the marketing hype doesn't stand up to even the slightest of scrutiny.

It's no sweat off my balls if someone wants to get invested in the WTF, but from every angle I've looked at it, it's a pig in a poke.

ETA:
Just to clarify, I have a couple thousand rounds through an AAC 300 BLK upper, which was a mixture of suppressed and non, subsonic and non. Much of that was at an EAG class, some at matches, and some just plinking. I didn't get the chance to shoot anything living with it, but did go on a hunt with 3 friends where 3 of us were shooting 5.56 and one was shooting 300. All four pigs died.

When it first came out, and I first got the upper, and first started getting cases of ammo to the house, and first got to play with the can... I was excited, and I was a fan. It just doesn't stand up to any scrutiny, and for me at least, there just isn't any reason for it.

we need to get over this idea that there's something wrong with 5.56, or that something else is more betterer.

[TGS]

we need to get over this idea that there's something wrong with 5.56, or that something else is more betterer.

Is this another classic rob_s strawman? I never said there was anything wrong with 5.56. Is this the part where you're going to create an argument on my behalf again?


Ugh. Whatever. I'm done. I said my piece to the OP about the caliber consideration and anything from here on out with you is just drivel.

[23JAZ]

I get what some of the 300 BLK benefits would be especially for HD however I think availability and cost out weigh those benefits. My intention for this rifle would primarily be HD however I also like the idea of still being able to reach out to 200 yards or more with a canned 5.56 even out of a short barrel. From what I'm hearing 300 BLK is pretty limited distance/accuracy wise. Plus keeping the caliber the same as my current rig keeps things simple. I'm sure one day I'll jump up to a bigger bore AR but more than likely it will be 7.62 x 51 and maybe a 6.8 ;)

[JM Campbell]

I get what some of the 300 BLK benefits would be especially for HD however I think availability and cost out weigh those benefits. My intention for this rifle would primarily be HD however I also like the idea of still being able to reach out to 200 yards or more with a canned 5.56 even out of a short barrel. From what I'm hearing 300 BLK is pretty limited distance/accuracy wise. Plus keeping the caliber the same as my current rig keeps things simple. I'm sure one day I'll jump up to a bigger bore AR but more than likely it will be 7.62 x 51 and maybe a 6.8 ;)

I have no problems hitting at 300 with 300blk. Subs and super with a 8" barrel and, a mil/mil 1-6x Bushnell tactical, once you find your dope it's on.

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[NerdAlert]

I thought the benefit of the 300blk was that it was designed around a ~8 inch barrel, so if you are building a dedicated HD sbr/pistol it would be a viable choice despite the price disparity of ammo. If you are fielding a longer barrel (>11 inches) I can't see a benefit to the 300. Just my .02.


Sent from my iPhone, I apologize in advance for typos.

[rob_s]

Is this another classic rob_s strawman? I never said there was anything wrong with 5.56. Is this the part where you're going to create an argument on my behalf again?


Ugh. Whatever. I'm done. I said my piece to the OP about the caliber consideration and anything from here on out with you is just drivel.

Yes, the drivel started the moment you brought up a fantasy caliber and then started wafling.

What is your experience with 300 BLK that would lead you to your recommendation?

[JV_]

Keep it civil and avoid the personal attacks.

[Rich]

I rather have a 10.5 or 11.5 than the 2 -14.5 carbines I have now.

Its not like I will be shooting bad guys at 50 yards so the shorter barrel would be fine for me. Plus it would be easier to maneuver around my house if used for HD.

Also wouldn't mind having a 9inch in 6.8

[23JAZ]

10.5 / 11.5 will retain plenty of velocity & reliability. Anything shorter gets really finicky.

With a typical can length added on, you are looking at just short of a 16" gun.

This is a PWS Mk110 upper on an M16a1. Suppressor is a AAC 416-SD. Next to it is my patrol gun, a DDM4V1:


http://tapatalk.imageshack.com/v2/14/11/17/ff29694c9c8634f0168b8f39525d6244.jpg
Just ordered a DD 11.5" 5.56 Gov profile 1:7. Now to search for a 13 or 15 inch handguard that will go over a standard diameter can.

[HCM]

Is there a standard diameter for cans ?

[JM Campbell]

Just ordered a DD 11.5" 5.56 Gov profile 1:7. Now to search for a 13 or 15 inch handguard that will go over a standard diameter can.

Does your suppressor thread on or quick disconnect with a dedicated mount/muzzle device? If quick disconnect you will not be able to run it under the rail.



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[Sigfan26]

Does your suppressor thread on or quick disconnect with a dedicated mount/muzzle device? If quick disconnect you will not be able to run it under the rail.



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Not so! Look at the silencerco Saker. It sounds awesome on everything from a 7" barrel to a 16" barrel (and everything in between). Doesn't sound quite as good as the SpecWar, but 10 times more versatile

[23JAZ]

Does your suppressor thread on or quick disconnect with a dedicated mount/muzzle device? If quick disconnect you will not be able to run it under the rail.



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Neither yet. Right now it is just a pile of parts. I think I am going to go with a screw on.

[ASH556]

There aren't a lot of people in the world who have shot suppressed SBR's enough to legitimately answer the question for you. Beyond that, you have individual preference. There are a lot of guys on the internet who don't own SBR's or suppressors, but will tell you what you "need." As for me, I'm not claiming to be an expert (there are already enough self-proclaimed experts on the internet) but I do own and shoot a suppressed SBR, so I'll share my perspective.

I have a Daniel Defense "MK18" which is a 10.3" barreled SBR with a 9.5" railed handguard. This setup was designed to have the combination of the shortest possible barrel with the longest possible handguard and still work with the carbine gas system. Mine has been 100% reliable (zero failures) for almost 2,000 rounds, suppressed or not, and even full-auto suppressed (On a post-sample Colt M4 lower). To me this rifle is absolutely perfect in every way. I set it up with an Aimpoint T-1, folding backup irons, a Geissele trigger, my preferred furniture, a Surefire light, and a VCAS sling. I've killed a deer with this rifle, I've competed at a high level in 3gun with this rifle (2nd place out of 38 shooters last month. Missed the leader, my buddy, by 6 seconds with him running a 16" gun with SJC titan brake and a Vortex 1-6), and if anything ever goes south, this will be the rifle I grab. It shoots MOA or better at 100yds with or without the can, and the addition of the can results in about a 1/2 MOA shift downward.

The bottom line is buy quality, proven parts, and run the gun. If something doesn't work, tear it off, sell it, and buy something else that does work. Don't be constrained by what others tell you is best. Listening to the advise of others with actual experience can be helpful and enlightening, but don't let it define things too much for you.

And...pics, because everyone loves 'em:

http://i854.photobucket.com/albums/ab104/ASH556/IMG_6600.jpg
https://farm4.staticflickr.com/3736/12206673764_c1587fd169_b.jpg (https://flic.kr/p/jAEoQu)Untitled (https://flic.kr/p/jAEoQu) by ASH556 (https://www.flickr.com/people/87859750@N03/), on Flickr
http://i854.photobucket.com/albums/ab104/ASH556/AFAFB8BE-C360-42F8-83B2-018F88F9037F.jpg
http://i854.photobucket.com/albums/ab104/ASH556/6039ECD0-0508-4205-9C39-BDCB6021BE6E.jpg

[Charlie Foxtrot]

I was thinking 5.56 or 6.8. Never really considered 300.

One thing you might consider - it is (somewhat) possible to chamber a 300 round into a 5.56 chamber. The 300 uses the 5.56 as the mother brass. Too many documented cases of experienced people blowing up their 5.56s with a 300 round. http://notonemoregunlaw.blogspot.com/2014/07/the-300-murphy-blk-irish.html Other than that, it is a VERY interesting round.

I also have a DD 6.8 SPC II, which I'm desperately in lust with. However, I use it for longer ranges - not close in SD/HD situations. So, I'll agree with several others with the suitability of the 5.56 for HD.

[rob_s]

Is there a standard diameter for cans ?

Generally 1.5" OD for most 5.56 and 7.62 cans, sometimes <1.5" for 9mm.

All of that said, a handguard with a >1.5" ID tends to be pretty fat, and I wouldn't run the handguard past the mounting point for a variety of other reasons, unless I was 100% certain I wouldn't be removing the can.

this might help (https://docs.google.com/spreadsheet/ccc?key=0Ajl2UPK0UHPscHdzd2hlZ2hOUXNHUnRyVUVVM3B0R EE&usp=sharing)

[SamuelBLong]

Just ordered a DD 11.5" 5.56 Gov profile 1:7. Now to search for a 13 or 15 inch handguard that will go over a standard diameter can.

What is your reasoning for wanting to have the rail + can setup like this ?

I don't see how it has any real benefit, and only see negatives...Especially for your stated purpose of HD 100m and in.

And if you are insistent on having it setup this way... Look at Seekins Precision. They make long hand guards that have 1.8" internal diameters, but still relatively trim outsides.

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[23JAZ]

What is your reasoning for wanting to have the rail + can setup like this ?

I don't see how it has any real benefit, and only see negatives...Especially for your stated purpose of HD 100m and in.

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Excuse my ignorance, but can you elaborate on those negatives? The only canned AR I've fired was set up like that and I really liked it. Honestly that's my only reasoning behind wanting one.

[SamuelBLong]

- Heat build up is the big one. Any rail that covers the back area of the suppressor is going to be taking lots of heat. Makes it pretty uncomfortable and sometimes even unbearable to grip the rail at all.

-Not being able to effectively either access your QD mount to remove a QD can or clean your threads ( if you're getting a thread mount).




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[HCM]

Rob, thanks. I have a spare 12 DD MFR - I'll save it for a longer build.

Other than heat what is the downside to perm mount cans like the DD ISR ?