Which SBR upper, DD MK18, BCM 11.5" or ?

[ARCHIVED THREAD] - Which SBR upper, DD MK18, BCM 11.5" or ?

Posted: 12/22/2014 10:41:06 AM EDT

Looking for a new SBR upper, it'll be used with an AAC M4-1000 can

Would you pick one of these two, or something else entirely?

Posted: 12/21/2014 4:31:25 PM EDT

[#1]

I went with an 11.5 BCM with a URX 3.1. It's awesome.

Posted: 12/21/2014 5:12:59 PM EDT

[#2]

Get both! If you're into clones i'd go MK 18. But as far as quality both uppers will be equal, main difference being the barrel of course 10.3 or 11.5

Posted: 12/21/2014 5:46:13 PM EDT

[#3]

The one thing pushing me towards the DD is that I can actually find one. The 11.5" BCM seems to be unobtanium right now.

Posted: 12/21/2014 6:20:23 PM EDT

[#4]

If you can find an 11.5" BCM, I honestly believe it is a better rifle. There is a big jump in velocity from the 10.3" to the 11.5" (over 100fps... a MUCH larger jump that you see going from 11.5"-12.5"). Also, for some reason DD decided to use a, IMO, a ridiculously large gas port (Approx .083 IIRC) which makes the gun kinda beat the shit out of itself. Both are good rifles but I would definitely give the edge to the 11.5" when it comes to performance.

Posted: 12/21/2014 7:46:22 PM EDT

[#5]

I started off with a factory MK18. It wasn't bad, used it in a class. Ended up switching out to a 11.5" upper a couple months afterwards.

You can't go wrong with either one. Do take a look at the FPS numbers. That extra 1.2 inches makes a big difference

Posted: 12/22/2014 1:03:18 AM EDT

[#6]

Agree, get both.

BCM 11.5" on the left and DDMK18 on the right (dedicated .22lr in the middle).

Posted: 12/22/2014 1:28:04 AM EDT

[#7]

Quoted:
I started off with a factory MK18. It wasn't bad, used it in a class. Ended up switching out to a 11.5" upper a couple months afterwards.

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Could you provide more details? Now that I have my SBR stamp and can stamp, I'd planned to run my Mk18 for classes.

Posted: 12/22/2014 1:54:34 AM EDT

[#8]

Quoted:

Quoted:
I started off with a factory MK18. It wasn't bad, used it in a class. Ended up switching out to a 11.5" upper a couple months afterwards.

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Could you provide more details? Now that I have my SBR stamp and can stamp, I'd planned to run my Mk18 for classes.

http://i762.photobucket.com/albums/xx269/911fan/ARFCOM/91bf7be6-37b3-4ee5-b6af-a9e3712ead02.jpg

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It ran fine during the class. I put an A5 buffer system on it. Recoil wasn't bad and it was much easier to use than my other 14.5" rifles. The thing started getting gummy after about 500 rounds and wouldn't lock open properly, but that may be due to the oil I was using.

Posted: 12/22/2014 2:00:36 AM EDT

[#9]

Quoted:

Quoted:
I started off with a factory MK18. It wasn't bad, used it in a class. Ended up switching out to a 11.5" upper a couple months afterwards.

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Could you provide more details? Now that I have my SBR stamp and can stamp, I'd planned to run my Mk18 for classes.

http://i762.photobucket.com/albums/xx269/911fan/ARFCOM/91bf7be6-37b3-4ee5-b6af-a9e3712ead02.jpg

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It ran fine during the class. I put an A5 buffer system on it. Recoil wasn't bad and it was much easier to use than my other 14.5" rifles. The thing started getting gummy after about 500 rounds and wouldn't lock open properly, but that may be due to the oil I was using.

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Thanks for the details. I definitely plan to carry a backup rifle with me, just in case.

Posted: 12/22/2014 2:05:10 AM EDT

[#10]

BCM

Posted: 12/22/2014 3:38:29 AM EDT

[#11]

I have a m18 and about 600rds down range. Never owned a DD anything until recently and I am very pleased at the fit and finish for a service rifle. Lower is a spec. keyhole forging as is the upper, both very clean and has a very nice machined lead in for mag changes, trigger crisp and consistent , don't know the pull force but typical. Added mbus pros and rear site lines up with center mark and windage is on center, pretty good upper to lower fit, IMI ejects at 3 and if I do my part can break skeet pretty easy at 200yds using a T2 RDS.

Posted: 12/22/2014 4:38:19 AM EDT

[#12]

I couldn't decide so I bought both. Factory DD MK18 and an 11.5 BCM with a 10 inch MI Gen2 SS tube. The BCM 11.5" seems to be a softer shooter and in my setup, a lighter upper. On the other hand the MK18 upper is very nice and I would eventually like to turn it into a clone rifle. Unless you really like the look of the MK18 upper (mainly the FDE rail), I would go with the BCM. FWIW I haven't shot either suppressed but have an AAC can pending.

Posted: 12/22/2014 4:51:30 AM EDT

[#13]

I'm also looking at these two options closely, but I'm still leaning towards the Adams Arms Tactical EVO 11.5" ($699 complete upper) because it is only a little bit more expensive, includes a nice rail, and of course piston is a big advantage for this role. The AA barrel is nitrated steel only though, without a chrome bore, however I've read good things about it (that's how they keep the cost down). I'd really like to know if anyone could compare them first hand.

Posted: 12/22/2014 12:27:03 PM EDT

[#14]

My 10.3" DD Barrel is slightly more accurate at 100yds where I do most of my bench shooting across a wider range of factory ammo than any BCM barrel I've ever had (16" mid length lightweight, 14.5" Mid Length BHF). You're going to get a little more velocity out of 11.5", but if you chronograph it I highly doubt it's going to be >100fps like someone mentioned.

They're both good setups, I don't think you could go wrong either way.

Posted: 12/22/2014 1:38:52 PM EDT

[#15]

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Quoted:
My 10.3" DD Barrel is slightly more accurate at 100yds where I do most of my bench shooting across a wider range of factory ammo than any BCM barrel I've ever had (16" mid length lightweight, 14.5" Mid Length BHF). You're going to get a little more velocity out of 11.5", but if you chronograph it I highly doubt it's going to be >100fps like someone mentioned.

They're both good setups, I don't think you could go wrong either way.

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It is. If you are shooting 77gr or something a little heavier like that, it may dip below 100fps but with standard m855, it is over 100fps. The velocity doesn't bother me quite as much as the violent way that those DD MK18 are setup to run. Their gas ports are entirely too large. You can deal with that with buffers and springs but you will need to play around with that if you want to get the most out of your rifle. But no, I'm not BS'ing the velocity info... its a legit 100. Both are great but out of the box, the BCM will run better IMO and it will obviously have slightly better ballistics bc of the extra length.

Posted: 12/22/2014 4:35:11 PM EDT

[#16]

11.5 is a bit better when it comes to ballistics. That said, I got the DD mk18 upper and it's been great. My only qualms are the oversized gas port and obnoxious laser engraving. I run an H3 and it's reliable with and without a can. I have no issue putting 20+ rds per mag on a 2/3 silhouette past 400 with an eotech, so it's more accurate than I'll ever need it to be.

Posted: 12/22/2014 9:16:31 PM EDT

[#17]

I'm partial to the BCM 11.5"

Posted: 12/22/2014 9:35:33 PM EDT

[#18]

I have a BCM 11.5 and a buddy has a DD mk18. The above poster's comment about the gun beating itself up MAY be true. His mangled a set of gas rings in the first 1000 or so rounds. He uses a much heavier set up than I do (magnifier, laser, etc) but his rifle has a lot more upward muzzle flip. My 11.5 has a sharp but flat straight to the rear impulse that makes it easier to shoot fast and accurate. The BCM is also without a doubt the most accurate chrome lined barrel Ive ever shot. To the point I won't say how accurate because no one would believe me. The DD seems pretty standard to slightly above average in terms of accuracy in my experience. That's probably down to these two individual rifles though. One area the DD is better is finish quality. It's very pretty and bystanders gravitate toward it at the range.

For me though the BCM 11.5 kills it in performance terms.

Posted: 12/23/2014 1:17:56 AM EDT

[#19]

My noveske mk18 clone makes me look like a better shot than I am. It's like a laser, it's so amazingly accurate. I'm also content with my 10.5 inch seekins upper.

Posted: 12/23/2014 8:27:55 AM EDT

[#20]

If it's mostly going to be used suppressed I can get the BCM 11.5 with the KMR. It will be much easier on your can and the KMR will help offset the weight if the suppressor. They haven't been in stock but you could easier buy the parts separately and build it.

Posted: 12/23/2014 11:12:01 AM EDT

[#21]

I highly recommend the 10.3" MK18 setup. Just make sure the suppressor will fit on the end if you are using the mk18 DD RIS rail, i dodnt have any issues but then again i use a direct thread so i dont know what is needed for the QD setup.

Posted: 12/23/2014 11:36:55 AM EDT

[#22]

Quote History

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I went with an 11.5 BCM with a URX 3.1. It's awesome.

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BCM is having a special where they toss in the free BCG and discounts on the CH

Posted: 12/23/2014 1:20:16 PM EDT

[#23]

I love my BCM 11.5 upper. I've been impressed with the accuracy and also the reliability. I have about 1800 rounds through it without any problems..half were suppressed.
I also have an LMT 10.5" upper that shoots great. I feel the recoil on that is less than the BCM when suppressed.

10.5" guns look better suppressed in my opinion lol but you can't go wrong with BCM

Posted: 12/23/2014 2:04:22 PM EDT

[#24]

I wish I had a BCM to compare with my m18, the quality of the DD product is obvious but they are pricy at suggested retail, as much as a upper tier LWRC once you add buis. And to compare the 8.5" lwrc I'd say the LWRC kicks more, don't know why but it is a piston system and shorter barrel and the m18 feels light weight up front

Gas rings going south after a 1k rounds sounds ridiculous?

And how do we know the gas port size on the DD CHF barrel and where is that posted?

Posted: 12/23/2014 3:39:33 PM EDT

[#25]

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Quoted:

And how do we know the gas port size on the DD CHF barrel and where is that posted?

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Gas port data regarding the DD MK18 is discussed quite a bit here: http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=239

Posted: 12/23/2014 7:39:44 PM EDT

[#26]

Quote History

Quoted:

Gas port data regarding the DD MK18 is discussed quite a bit here: http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=239

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Quote History

Quoted:

Quoted:
And how do we know the gas port size on the DD CHF barrel and where is that posted?

Gas port data regarding the DD MK18 is discussed quite a bit here: http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=239

I read what Amphibian said about the port size being .080 dia on page 283 as well as read page 282 and 284. Who is Amphibian and is he reputable?

Posted: 12/23/2014 10:05:08 PM EDT

[#27]

I'm a supporting dealer here on AR15.com and president of MicroMOA.com

I never said the port was .080. There is no wire gauge .080 bit. Wire gauge goes from .078 then .081 then .082.

Please read what I posted here: http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=233

We have an Dealer Forum here: http://www.ar15.com/forums/f_2/543_MicroMOA.html

Quite a few people running our blocks on DD MK18's as well as our own barrels.

Just do a Google search on us for feedback or I can try to pull up some links.

Thanks!

Posted: 12/23/2014 10:58:40 PM EDT

[#28]

Quote History

Quoted:
I'm a supporting dealer here on AR15.com and president of MicroMOA.com
I never said the port was .080. There is no wire gauge .080 bit. Wire gauge goes from .078 then .081 then .082.
Please read what I posted here: http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=233
We have an Dealer Forum here: http://www.ar15.com/forums/f_2/543_MicroMOA.html
Quite a few people running our blocks on DD MK18's as well as our own barrels.
Just do a Google search on us for feedback or I can try to pull up some links.
Thanks!

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Haha, .082 got it, thank you for responding. So are you guys measuring this because no one seems to give out that info or I'm not finding it. I really don't know what's specified on a regular 14.5" barrel let alone a 10.3". Must be a drawing somewhere? I have drawings on lowers and uppers but no barrels?

Posted: 12/23/2014 11:24:16 PM EDT

[#29]

Quote History

Quoted:

Haha, .082 got it, thank you for responding. So are you guys measuring this because no one seems to give out that info or I'm not finding it. I really don't know what's specified on a regular 14.5" barrel let alone a 10.3". Must be a drawing somewhere? I have drawings on lowers and uppers but no barrels?

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See the following link and on Page 4 from the NSWC Crane where they specified .070" for the 10.3" MK18: http://www.dtic.mil/ndia/2003smallarms/john.ppt

DD and several other manufacturers overgass their civilian barrels since commercial customers may be feeding them Tula and all kinds of weak ammo that a military issue MK18 barrel most likely won't see.

We take advantage of that huge .082 port and use it for the adverse position with our gas block. Our Govnah's all come with two regulator plates and the MK18 specific one comes w/ a .070/.049/.082 and a .073/.052/.082 regulator plate. We need to know the port size of the barrel so that we can align our block up with the port in the barrel and use that as our alignment/installation position which also doubles as the adverse position....rarely does the port in the barrel match the 'optimal' port size as most barrels are overgassed.

See our installation page for details on what I'm talking about: http://micromoa.com/?page_id=86

Also regarding various port sizes, it is not so simple to say X length barrel and X length gas system and X caliber = X size gas port (of course there is a range of port sizes that varies between manufacturers). Rifling design and bore diameter will affect the appropriate size gas port for a particular configuration.

Read this for more info regarding that: http://micromoa.com/?page_id=855

Thanks!

Posted: 12/24/2014 1:07:57 AM EDT

[#30]

Quote History

Quoted:

See the following link and on Page 4 from the NSWC Crane where they specified .070" for the 10.3" MK18: http://www.dtic.mil/ndia/2003smallarms/john.ppt
DD and several other manufacturers overgass their civilian barrels since commercial customers may be feeding them Tula and all kinds of weak ammo that a military issue MK18 barrel most likely won't see.
We take advantage of that huge .082 port and use it for the adverse position with our gas block. Our Govnah's all come with two regulator plates and the MK18 specific one comes w/ a .070/.049/.082 and a .073/.052/.082 regulator plate. We need to know the port size of the barrel so that we can align our block up with the port in the barrel and use that as our alignment/installation position which also doubles as the adverse position....rarely does the port in the barrel match the 'optimal' port size as most barrels are overgassed.
See our installation page for details on what I'm talking about: http://micromoa.com/?page_id=86
Also regarding various port sizes, it is not so simple to say X length barrel and X length gas system and X caliber = X size gas port (of course there is a range of port sizes that varies between manufacturers). Rifling design and bore diameter will affect the appropriate size gas port for a particular configuration.
Read this for more info regarding that: http://micromoa.com/?page_id=855
Thanks!

View Quote View All Quotes

View All Quotes

Quote History

Quoted:

Quoted:

Haha, .082 got it, thank you for responding. So are you guys measuring this because no one seems to give out that info or I'm not finding it. I really don't know what's specified on a regular 14.5" barrel let alone a 10.3". Must be a drawing somewhere? I have drawings on lowers and uppers but no barrels?

See the following link and on Page 4 from the NSWC Crane where they specified .070" for the 10.3" MK18: http://www.dtic.mil/ndia/2003smallarms/john.ppt
DD and several other manufacturers overgass their civilian barrels since commercial customers may be feeding them Tula and all kinds of weak ammo that a military issue MK18 barrel most likely won't see.
We take advantage of that huge .082 port and use it for the adverse position with our gas block. Our Govnah's all come with two regulator plates and the MK18 specific one comes w/ a .070/.049/.082 and a .073/.052/.082 regulator plate. We need to know the port size of the barrel so that we can align our block up with the port in the barrel and use that as our alignment/installation position which also doubles as the adverse position....rarely does the port in the barrel match the 'optimal' port size as most barrels are overgassed.
See our installation page for details on what I'm talking about: http://micromoa.com/?page_id=86
Also regarding various port sizes, it is not so simple to say X length barrel and X length gas system and X caliber = X size gas port (of course there is a range of port sizes that varies between manufacturers). Rifling design and bore diameter will affect the appropriate size gas port for a particular configuration.
Read this for more info regarding that: http://micromoa.com/?page_id=855
Thanks!

Awesome! Thanks for that info. I would like to see a mk18 barrel drawing or a Danial Defence barrel drawing. That info exists somewhere?