View Full Version : DD Midlength 16” Undergassed?
SouthwestAviator
02-25-19, 10:12
From the little info on this I’m able to find, it appears that Daniel Defense midlength gov’t profile 16” guns use a .072” gas port diameter. Can anyone confirm this? I assume DD doesn’t disclose that information like most manufacturers.
If it is .072”, doesn’t that seem a bit small? BCM uses .076” for the same setup. Would the DD 16” midlength have less reliability especially with weaker ammo?
From the little info on this I’m able to find, it appears that Daniel Defense midlength gov’t profile 16” guns use a .072” gas port diameter. Can anyone confirm this? I assume DD doesn’t disclose that information like most manufacturers.
If it is .072”, doesn’t that seem a bit small? BCM uses .076” for the same setup. Would the DD 16” midlength have less reliability especially with weaker ammo?
I have a Daniel Defense M4v7LW that has a mid-length pencil barrel, and it has eaten everything I have fed it.
RVTMaverick
02-25-19, 10:55
According to BRT's web-site: it is but not by much, looks like they're showing the same as BCM, a .076", I guess it could depend upon what they're (DD) is using for Buffer and Buffer Spring, BCG?
From the little info on this I’m able to find, it appears that Daniel Defense midlength gov’t profile 16” guns use a .072” gas port diameter. Can anyone confirm this? I assume DD doesn’t disclose that information like most manufacturers.
If it is .072”, doesn’t that seem a bit small? BCM uses .076” for the same setup. Would the DD 16” midlength have less reliability especially with weaker ammo?
I have been running a DDM4v5 as my "go-to" since 2012 time frame. It had a 16 inch mid-length barrel on it until I switched it out with a 14.5 mid-length about three years ago. I have primarily run Federal ammunition since swapping barrels, however, I ran a multitude of different ammunition brands and power through the 16 inch. I have had no issue what so ever with either barrel.
SouthwestAviator
02-25-19, 11:16
According to BRT's web-site: it is but not by much, looks like they're showing the same as BCM, a .076", I guess it could depend upon what they're (DD) is using for Buffer and Buffer Spring, BCG?
Afaik the DDM4V5 (the one I’m looking to get) uses a GI buffer spring and H buffer. Probably identical to what BCM uses.
It sounds like with good ammo in optimal conditions the undergassing isn’t an issue, but I wonder if it’ll start to hiccup in harsh/cold conditions and low power ammo.
Those of you with midlength 16” gov’t profile DD’s, specifically the M4V5, how many trouble free rounds do you have through it and what kind of ammo do you use?
I might go with a carbine length 14.5” but am considering the mid.
My DD 16" mid runs Wolf Gold and various 5.56 at temps down to -5F. A5H2 and Tubbs AR10 spring. Standard M4 BCG, A2 FH. 4-5K rounds over the years and no problems.
SouthwestAviator
02-25-19, 11:50
My DD 16" mid runs Wolf Gold and various 5.56 at temps down to -5F. A5H2 and Tubbs AR10 spring. Standard M4 BCG, A2 FH. 4-5K rounds over the years and no problems.
When did you get your’s? It sounds like they may have shrunken the gas port since 2017 or so.
2015-ish... I measured mine at about .072. I used drill bits, and a 1.8mm (.0709") fit, but a #49 (.073") would not.
As additional info, my DD barrels are quite accurate. MOA 10-shot groups with the right ammo. They shoot 75 Gold Dots and 77 SMKs particularly well. 64 Gold Dot doesn't group nearly as good. I cut down a 14.5 to about 10.75 several years ago and it continues to impress, with north of 10k rounds through it, mostly suppressed.
http://i151.photobucket.com/albums/s122/mq105/DD%2010.75%20tgt2_2.jpg (http://s151.photobucket.com/user/mq105/media/DD%2010.75%20tgt2_2.jpg.html)
http://i151.photobucket.com/albums/s122/mq105/DD%2010.75%20pic1.jpg (http://s151.photobucket.com/user/mq105/media/DD%2010.75%20pic1.jpg.html)
http://i151.photobucket.com/albums/s122/mq105/DD%2010.75%20tgt3.jpg (http://s151.photobucket.com/user/mq105/media/DD%2010.75%20tgt3.jpg.html)
http://i151.photobucket.com/albums/s122/mq105/DD%2010.75%20tgt1.jpg (http://s151.photobucket.com/user/mq105/media/DD%2010.75%20tgt1.jpg.html)
Here is the 16". Bi-pod, rear bag and 2.5-10x NF.
http://i151.photobucket.com/albums/s122/mq105/DD%20tgt%203.jpg (http://s151.photobucket.com/user/mq105/media/DD%20tgt%203.jpg.html)
http://i151.photobucket.com/albums/s122/mq105/DD%20tgt%201.jpg (http://s151.photobucket.com/user/mq105/media/DD%20tgt%201.jpg.html)
http://i151.photobucket.com/albums/s122/mq105/DD%20tgt%202.jpg (http://s151.photobucket.com/user/mq105/media/DD%20tgt%202.jpg.html)
vicious_cb
02-25-19, 12:17
When did you get your’s? It sounds like they may have shrunken the gas port since 2017 or so.
AFAIK they run 0.076" on their midlengths.
vicious_cb
02-25-19, 12:17
When did you get your’s? It sounds like they may have shrunken the gas port since 2017 or so.
AFAIK they run 0.076" on their midlengths.
CajunCourier
02-25-19, 12:27
I like the new avatar, Viscious.
The midlength 14.5" is 0.076, maybe Daniel Defense determined that .073" is optimal for 16".
One of my shooting buddies has a DD M4V5. Shoots mostly steel cases Tula and Wolf. No issues that I’ve seen.
I don't have exact numbers on how much of each brand of ammo that was run through my 16 inch mid-length. However, I do know that my limited resources at the time dictated that I shoot what I could get my hands on. I do know that it had 1,000 round cases of Federal M193, Lake city M855, and Privi partizan. The rest were various amounts of Freedom munitions, Aguila, Matech (I think), some Winchester, and some local .223 remanufactured. The only stipulation that I had was "not steel", sorry for not being specific. The 14.5 is also a DD CHF barrel and has only had Federal run through it. As far as buffers go, I ran the standard spring with H2 until I replaced it with a Geissele super 42 spring and buffer. The carbine is going on seven years old now and the only problems I ever had were magazine related.
As an aside, I recently bought another DD CHF 14.5 mid-length barrel for another build that is still a work in progress. That does not have enough rounds through it yet to make any kind of judgement, but there have been no problems with it yet.
SouthwestAviator
02-25-19, 12:57
I don't have exact numbers on how much of each brand of ammo that was run through my 16 inch mid-length. However, I do know that my limited resources at the time dictated that I shoot what I could get my hands on. I do know that it had 1,000 round cases of Federal M193, Lake city M855, and Privi partizan. The rest were various amounts of Freedom munitions, Aguila, Matech (I think), some Winchester, and some local .223 remanufactured. The only stipulation that I had was "not steel", sorry for not being specific. The 14.5 is also a DD CHF barrel and has only had Federal run through it. As far as buffers go, I ran the standard spring with H2 until I replaced it with a Geissele super 42 spring and buffer. The carbine is going on seven years old now and the only problems I ever had were magazine related.
As an aside, I recently bought another DD CHF 14.5 mid-length barrel for another build that is still a work in progress. That does not have enough rounds through it yet to make any kind of judgement, but there have been no problems with it yet.
That's plenty specific enough. Sounds good.
I'm wondering if I should go with the midlength 16" or carbine 14.5".
This is the only source I've been able to find gas port diameter measurements: https://docs.google.com/spreadsheets/d/1tXunBDX5Gaz87BqxwNxDUlWNK9nEv-cZEQoLq2JXXrk/edit#gid=766121382
My DD 14.5 that I chopped is .067" and runs very well suppressed (and not) at 10.75".
It's most likely just fine.
Differences with the chamber and bore can affect the required port size somewhat.
14.5" MID is a great configuration.
From the little info on this I’m able to find, it appears that Daniel Defense midlength gov’t profile 16” guns use a .072” gas port diameter. Can anyone confirm this? I assume DD doesn’t disclose that information like most manufacturers.
If it is .072”, doesn’t that seem a bit small? BCM uses .076” for the same setup. Would the DD 16” midlength have less reliability especially with weaker ammo?
SouthwestAviator
02-25-19, 15:07
It's most likely just fine.
Differences with the chamber and bore can affect the required port size somewhat.
14.5" MID is a great configuration.
Would the 16” midlength with the .072” be as not picky on ammo as the 14.5” carbine length?
Did we not already go through this a month or two ago?
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SouthwestAviator
02-25-19, 19:45
Did we not already go through this a month or two ago?
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Well, right now I'm talking about the gas port size of the DDM4V5 specifically. I've pretty much already determined that a properly-gassed midlength has reliability and durability advantages over carbine. Up until this morning I assumed Daniel Defense used a .076" gas port diameter for their 16" mids just like their 14.5" mids and BCM's, but from that google doc data it appears that they use a smaller gas port than normal. I'm just wondering if anyone's had undergassing issues with current production DD 16" mids.
Well, right now I'm talking about the gas port size of the DDM4V5 specifically. I've pretty much already determined that a properly-gassed midlength has reliability and durability advantages over carbine. Up until this morning I assumed Daniel Defense used a .076" gas port diameter for their 16" mids just like their 14.5" mids and BCM's, but from that google doc data it appears that they use a smaller gas port than normal. I'm just wondering if anyone's had undergassing issues with current production DD 16" mids.
Your last question was whether a DD mid be less reliable than a DD carbine. I'm almost positive at least one of your threads in the last few months had pages of discussion on the same question, not to mention all of the other threads on here. DD, while not my preference, makes good guns.
Paralysis by analysis. Quit overthinking this and buy a damn rifle. Either one will kick ass I’m sure.
I My DD 16” middi runs like a top as I purchased it. No “tuning” needed with the H buffer. I added a Geissele SSA, just because I got spoiled by the one on my 20” Hbar, but I only shoot 5.56 pressure XM193, XM855 & Black Hills 77gr OTM.
No .223, so I can’t help you there.
ETA: my DDM4V5 is my favorite rifle. I was raised on Bushmaster, which I equated to my Honda Civic, while the DD is like my wife’s Audi A5–solid, sound & feels like it means business & mine doesn’t have the annoying “sproing” when it recoils. I’m not sure why—I suspect commercial receiver extension vs. mil spec. As others have already said, it’s a damn good gun.
From the little info on this I’m able to find, it appears that Daniel Defense midlength gov’t profile 16” guns use a .072” gas port diameter. Can anyone confirm this? I assume DD doesn’t disclose that information like most manufacturers.
If it is .072”, doesn’t that seem a bit small? BCM uses .076” for the same setup. Would the DD 16” midlength have less reliability especially with weaker ammo?
I reached out a few years ago when I bought a barrel, from DD customer support, "Daniel Defense 14.5" Mid-length barrels have a 0.076 gas port size".
You can email them and they will tell you, its not a secret.
MSparks909
02-26-19, 09:00
Paralysis by analysis. Quit overthinking this and buy a damn rifle. Either one will kick ass I’m sure.
This. Buy a DD or a BCM middy and call it good. FWIW M4V5 here and I’ve got ~6,000 through it. Cleaned 3x, shot about 500 rounds of Wolf .223 steel cases over the years. Usually shoot Wolf Gold though.
SouthwestAviator
02-26-19, 11:38
I reached out a few years ago when I bought a barrel, from DD customer support, "Daniel Defense 14.5" Mid-length barrels have a 0.076 gas port size".
You can email them and they will tell you, its not a secret.
I just called Daniel Defense. I was pleased that they could tell me the gas port diameter of their 16" midlength gov't profile barrels, and it's confirmed at .073". He told me he's run many kinds of .223 in it with no problems. Very nice and knowledgeable guy. I assumed DD didn't give out that information like Spikes, BCM, and other manufacturers, but I'm glad I was wrong. Definitely makes me want to do business with Daniel Defense.
Since the 16" mid has more dwell time than the 14.5" mid, I suppose it makes sense that the gas port is slightly smaller. They nailed it with the 14.5" mid so I'm sure the 16" mid is good to go too.
They also told me there's not really a reliability difference between a 14.5" carbine and a 16" midlength.
I'm gonna go with the middy 16" DD.
...Since the 16" mid has more dwell time than the 14.5" mid...
...about half of a millionthof a second more...
I suppose it makes sense that the gas port is slightly smaller.
Gas operated rifles are powered by the residual pressure left in the bore after the bullet exits the muzzle. The gas pressure at the port takes a little bit longer to vent to atmospheric with extra inch and a half length of the 16 inch barrel than the 14.5 inch barrel.
The very brief extra time the bullet in the bore makes no practical difference in the operation of the rifle.
I prefer the handling of a 14.5 inch barrel over the 16 inch.
I just called Daniel Defense. I was pleased that they could tell me the gas port diameter of their 16" midlength gov't profile barrels, and it's confirmed at .073". He told me he's run many kinds of .223 in it with no problems. Very nice and knowledgeable guy. I assumed DD didn't give out that information like Spikes, BCM, and other manufacturers, but I'm glad I was wrong. Definitely makes me want to do business with Daniel Defense.
Since the 16" mid has more dwell time than the 14.5" mid, I suppose it makes sense that the gas port is slightly smaller. They nailed it with the 14.5" mid so I'm sure the 16" mid is good to go too.
They also told me there's not really a reliability difference between a 14.5" carbine and a 16" midlength.
I'm gonna go with the middy 16" DD.
Glad I could help, I've now got 2 DD 16" midlengths, and I love them. I have to say though, my personal favorite is my 14.5" ELW BCM, although, this is the definition of 1st World problems at this point.
SouthwestAviator
02-27-19, 19:57
I ordered the midlength DDM4 midlength today. Once I get it, I'm going to lubricate it and take it out to the range. I'm gonna run a few hundred rounds of 5.56 through it before verifying function with low-powered ammunition.
Good deal.
Sounds like they are on point.
I just called Daniel Defense. I was pleased that they could tell me the gas port diameter of their 16" midlength gov't profile barrels, and it's confirmed at .073". He told me he's run many kinds of .223 in it with no problems. Very nice and knowledgeable guy. I assumed DD didn't give out that information like Spikes, BCM, and other manufacturers, but I'm glad I was wrong. Definitely makes me want to do business with Daniel Defense.
Since the 16" mid has more dwell time than the 14.5" mid, I suppose it makes sense that the gas port is slightly smaller. They nailed it with the 14.5" mid so I'm sure the 16" mid is good to go too.
jerrysimons
02-27-19, 21:05
I just called Daniel Defense. I was pleased that they could tell me the gas port diameter of their 16" midlength gov't profile barrels, and it's confirmed at .073". He told me he's run many kinds of .223 in it with no problems. Very nice and knowledgeable guy. I assumed DD didn't give out that information like Spikes, BCM, and other manufacturers, but I'm glad I was wrong. Definitely makes me want to do business with Daniel Defense.
Since the 16" mid has more dwell time than the 14.5" mid, I suppose it makes sense that the gas port is slightly smaller. They nailed it with the 14.5" mid so I'm sure the 16" mid is good to go too.
They also told me there's not really a reliability difference between a 14.5" carbine and a 16" midlength.
I'm gonna go with the middy 16" DD.
Their 10.3 barrels were grossly over gassed for while.
.073” is good for a general purpose 16” mid especially if mainly unsupressed. I have been running a .073” gas-block port insert on a Sionics 16” mid barrel for a while, it works great, could stand to go smaller with a silencer mounted full time.
SouthwestAviator
02-27-19, 21:32
Their 10.3 barrels were grossly over gassed for while.
.073” is good for a general purpose 16” mid especially if mainly unsupressed. I have been running a .073” gas-block port insert on a Sionics 16” mid barrel for a while, it works great, could stand to go smaller with a silencer mounted full time.
Have you tried it with .223 pressure ammo without the suppressor yet, and if so, how'd it run?
My next AR is still going to be a SOCOM-style 14.5" carbine. But no harm in having a mid at least
jerrysimons
02-27-19, 21:53
Have you tried it with .223 pressure ammo without the suppressor yet, and if so, how'd it run?
My next AR is still going to be a SOCOM-style 14.5" carbine. But no harm in having a mid at least
Yeah, runs great. I also use the LMT E Carrier and VLTOR A5 rifle buffers but I am confident .073” on a 16” mid will run everything well with a standard carrier and H1/2 carbine buffers. DD has had a bit of a reputation for overgassing for a little while, maybe that has changed for the better but I really don’t think you need to worry about undergassing on a factory gun, almost every company would error closer to overgassing their barrels than under.
vicious_cb
02-27-19, 23:23
Yeah, runs great. I also use the LMT E Carrier and VLTOR A5 rifle buffers but I am confident .073” on a 16” mid will run everything well with a standard carrier and H1/2 carbine buffers. DD has had a bit of a reputation for overgassing for a little while, maybe that has changed for the better but I really don’t think you need to worry about undergassing on a factory gun, almost every company would error closer to overgassing their barrels than under.
I would consider a 0.073" port on a 16" undergassed, or at the least strictly 5.56 ammo only for reliable function. Remember, BCM's 0.076" midlength ports are intended to function optimally with 5.56 pressure ammo. Hodge barrel which are gassed to play nice with suppressors and M855A1 are running 0.075"...
I have a BCM 12.5 that I was told by BCM has a .075 gas port. Interesting that there 16"s are .076
I have a BCM 12.5 that I was told by BCM has a .075 gas port. Interesting that there 16"s are .076
Weird since BCM doesn’t typically state what their gas ports are.
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SouthwestAviator
02-28-19, 06:05
I would consider a 0.073" port on a 16" undergassed, or at the least strictly 5.56 ammo only for reliable function. Remember, BCM's 0.076" midlength ports are intended to function optimally with 5.56 pressure ammo. Hodge barrel which are gassed to play nice with suppressors and M855A1 are running 0.075"...
I don't like hearing that...
I require my rifles to be able to run low pressure .223 since there are times when that's all that's available. For military use a small gas port makes sense because they're only using high pressure ammunition, but things are different in the civilian world. I have a lot of PMC Bronze that runs in my 6920 without a hitch. If the DD mid 16" can't run it, it's of no more use to me than a paperweight. I'd return to carbine length and never look back.
jerrysimons
02-28-19, 06:58
I would consider a 0.073" port on a 16" undergassed, or at the least strictly 5.56 ammo only for reliable function. Remember, BCM's 0.076" midlength ports are intended to function optimally with 5.56 pressure ammo. Hodge barrel which are gassed to play nice with suppressors and M855A1 are running 0.075"...
It works. Hodge’s (current) mod 2 barrel’s are 14.5” mid length with a 0.075” GP and 12.5” carbine with 0.0625” gp. We are talking 16” mid length with 0.073” which is only one step down from 0.076”, there is quite a bit of margin for additional function and low ammo pressures on a BCM 16” mid with a 0.076” gp. 0.073” is good to go, worst case scenario you use a h1 or carbine buffer. Op get it out and shoot it, go out in cold weather a shoot your cheep .223. Then you will know and not be stuck on internet anylysis paralisys.
0.075” is huge for a 12.5” carbine, I would question that from BCM, Noveske’s are notoriously over gassed and they stopped at 0.071” on a 12.5” carbine. I have a 0.065” 12.5” carbine barrel running 223 well out of a low back pressure silencer, LMT E-carrier, and A5H4 buffer with green spring.
jerrysimons
02-28-19, 07:13
I don't like hearing that...
I require my rifles to be able to run low pressure .223 since there are times when that's all that's available. For military use a small gas port makes sense because they're only using high pressure ammunition, but things are different in the civilian world. I have a lot of PMC Bronze that runs in my 6920 without a hitch. If the DD mid 16" can't run it, it's of no more use to me than a paperweight. I'd return to carbine length and never look back.
Is you apprehension simply going from 16” carbine gas to 16” mid length? There is nothing to worry about with that move. 16” carbine gas is way less than ideal at .223/5.56 pressures.
Weird since BCM doesn’t typically state what their gas ports are.
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They will tell you if you ask.
MSparks909
02-28-19, 08:15
I don't like hearing that...
I require my rifles to be able to run low pressure .223 since there are times when that's all that's available. For military use a small gas port makes sense because they're only using high pressure ammunition, but things are different in the civilian world. I have a lot of PMC Bronze that runs in my 6920 without a hitch. If the DD mid 16" can't run it, it's of no more use to me than a paperweight. I'd return to carbine length and never look back.
You’re grossly overthinking this. The DD will run fine on .223 ammo. Buy it and enjoy...
I don't like hearing that...
I require my rifles to be able to run low pressure .223 since there are times when that's all that's available. For military use a small gas port makes sense because they're only using high pressure ammunition, but things are different in the civilian world. I have a lot of PMC Bronze that runs in my 6920 without a hitch. If the DD mid 16" can't run it, it's of no more use to me than a paperweight. I'd return to carbine length and never look back.
It’d be pretty stupid to blame the failure of one manufacturer on an entire system, but you do you.
They will tell you if you ask.
Wouldn’t tell me, not a few others that I know of.
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It’d be pretty stupid to blame the failure of one manufacturer on an entire system, but you do you.
Wouldn’t tell me, not a few others that I know of.
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I have the email. Have one from DD also.
https://i.imgur.com/GJ6TgOn.jpg
Well, right now I'm talking about the gas port size of the DDM4V5 specifically. I've pretty much already determined that a properly-gassed midlength has reliability and durability advantages over carbine. Up until this morning I assumed Daniel Defense used a .076" gas port diameter for their 16" mids just like their 14.5" mids and BCM's, but from that google doc data it appears that they use a smaller gas port than normal. I'm just wondering if anyone's had undergassing issues with current production DD 16" mids.
What happens when you shoot it?
I swear, sometimes y'all make me feel like I'm playing cards with my brother's kids.
As stated numerous times in this thread, Daniel Defense rifles will eat anything you put through them. I can promise you that there would be a thread here detailing the problem if they didn't.
I just got done taking a 2-Day Carbine class over the weekend. I ran my DD 16" Mid-Length on a Centurion lower with an A5H1. Ran hundreds and hundreds of rounds through it including: PMC Bronze, AE 223, Winchester 223, RemyPete 223. Ran great and without hiccups. Only malfunctions were user induced. Your barrel will be fine and not undergassed.
Damn. I thought this was resolved and you picked a DDM4V5. Am I wrong? Wtf are we still talking about this?Take some .223 and your new boom stick to the range and find out for yourself. Or just get a bolt action.
I don’t have any DD rifles. Yet. But I’ve never had a problem shooting .223 out of anything. Colt carbine. BCM middy. PSA middy for ****’s sake. Remington rifle length. Yes Remington AR. If PSA and Remy can do it. I’m sure that DD will run like a champ.
SouthwestAviator
02-28-19, 20:04
It’d be pretty stupid to blame the failure of one manufacturer on an entire system, but you do you.
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It wouldn't be from one manufacturer, this would be #2. A close range buddy has a BCM 14.5" mid and that run low pressure .223. It runs better with a carbine buffer but still doesn't lock back sometimes. Can't blame BCM, they state outright not to use that ammo.
I'd be surprised if the DD 16" mid has problems with it though. Most that have them seem to report them running anything, same with BCM 16" mids.
https://i.imgur.com/GJ6TgOn.jpg
No $hit
It wouldn't be from one manufacturer, this would be #2. A close range buddy has a BCM 14.5" mid and that run low pressure .223. It runs better with a carbine buffer but still doesn't lock back sometimes. Can't blame BCM, they state outright not to use that ammo.
I'd be surprised if the DD 16" mid has problems with it though. Most that have them seem to report them running anything, same with BCM 16" mids.
That’s pretty weird since I’ve put a few thousand rounds through 14.5 BCM mids and I don’t think any of it has ever been actual 5.56. Sounds like something is up.
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