Older DD or Newer 6720

[Hapworth]

Or you could stop being lazy.

There have been lots reports of over-gassing with DD.

I really don't care either way.

What you don't care about is irrelevant. Overly broad, arguably negative claims about a manufacturer's product minus verifying -- or even supporting -- evidence isn't what this site's about. Advising everyone else to do your legwork in order to substantiate your claims is the definition of lazy.

[scooter22]

What you don't care about is irrelevant. Overly broad, arguably negative claims about a manufacturer's product minus verifying -- or even supporting -- evidence isn't what this site's about. Advising everyone else to do your legwork in order to substantiate your claims is the definition of lazy.

What do you want me to do? Purchase DD barrels in every length and test them?

I don't have the time nor do I care to search for threads substantiating my claims.

If you think my claim is false, then ignore it and carry on.

[MountainRaven]

I always thought that M4c was a place where if you said something, you would have to back it up with evidence.

Or offer the qualifier, "In my experience," denoting that you have seen their guns and they have been over-gassed.

If it's second-hand information, then you qualify it by saying, "Leo Valentine says they're over-gassed," (you may have to explain who Leo Valentine is).

If you're in a hurry, you could qualify it by saying, "I remember hearing/reading that they're over-gassed, but I can't find where I heard/read it. Will update when I find the source."

People with the title of 'Subject Matter Expert' or 'Industry Professional' might be able to get away with not qualifying their statements - there is a reason why they have those titles, afterall.

&c., &c., &c.

IOW, if you cannot substantiate what you're saying, don't say it at all.

[TinyCrumb]

I always thought that M4c was a place where if you said something, you would have to back it up with evidence.

Or offer the qualifier, "In my experience," denoting that you have seen their guns and they have been over-gassed.

If it's second-hand information, then you qualify it by saying, "Leo Valentine says they're over-gassed," (you may have to explain who Leo Valentine is).

If you're in a hurry, you could qualify it by saying, "I remember hearing/reading that they're over-gassed, but I can't find where I heard/read it. Will update when I find the source."

People with the title of 'Subject Matter Expert' or 'Industry Professional' might be able to get away with not qualifying their statements - there is a reason why they have those titles, afterall.

&c., &c., &c.

IOW, if you cannot substantiate what you're saying, don't say it at all.

There's no need for this in this case because this is not something that people actually dispute. It's common knowledge at this point. Nobody actually says "I believe DD's barrels are not overgassed". That would be dumb.

The military CQBR 10.3" barrel done by Crane & Colt has (and is spec'd) for a .070 gas port for optimum reliability with M855 ammo. It's also proved to have 100% reliability with M193, Mk 262 and all other .mil 5.56 loads.

If you try to run this same port size with commercial ammo, you will experience some malfunctions with super weak ammo. This is usually steel case Tula & Wolf .223 but can also happen with ammo like PMC .223 if your gun is particularly dirty, etc…

So ALL manufacturers that make a 10.3" or 10.5" barrel for the commercial market decided to enlarge their gas port from mil-spec for increased reliability with ammo commonly used in civilian rifles. Most went with a gas port of around .074 which has been proven over many years and millions of rounds to be great.

DD decided to go way further. They've stated multiple times that their gas port right now is at .081. But many of us have measured (both with calipers and pin gauges) new barrels and seen ports as high as .088. This IS extremely overgassed and will produce malfunctions with a suppressor on. DD JUST commented on TOS not more than a week ago and validated this — and they've done so numerous times throughout the years. You can try to mitigate this with an extremely heavy buffer (Griffin, H3, etc…) and possibly a strong spring, but you still end up with increased recoil, increased parts wear, etc… And sure, you could say that well it's great because you want your rifle 100% reliable with any ammo you throw at it. Except that nobody has ever reported a malfunction with all other manufacturers barrels that are in the .074 - .076 range (LMT, Noveske, BA, Colt, etc…).

It's pretty ridiculous to claim otherwise since there's years of data readily accessible with nothing more than Google and plenty of official statements from the company itself verifying it. Nobody is going to go buy every single barrel in the market just to "show evidence" of something that is already common knowledge. I'd feel pretty comfortable stating that a Geissele SSA-E is a much smoother, cleaner trigger than a standard Colt mil-spec but I'm not about to bust out a video camera and a bunch of tools to "show evidence".

Many (not all) Daniel Defense barrels are overgassed for what they need to be for 100% reliability. This can also decrease reliability if you ever intend on putting a suppressor on that barrel. It's up to you whether that's important or not. Many people run DD barrels over many many years and have 0 problems with them.

Personally, I never intend to run Tula .223 with my rifles and would rather have a rifle closer to mil-spec, that's softer shooting, easier on parts, and that I can run a can on without ever worrying about malfunctions.

[PrevailFI]

I bought the DD yesterday- gassy old POS that it is...

I've seen it perform for months at our 2 gun matches; it will do just fine as a 4th AR. Thanks for all your help.

Sent from my XT907 using Tapatalk

[MountainRaven]

There's no need for this in this case because this is not something that people actually dispute. It's common knowledge at this point. Nobody actually says "I believe DD's barrels are not overgassed". That would be dumb.

The military CQBR 10.3" barrel done by Crane & Colt has (and is spec'd) for a .070 gas port for optimum reliability with M855 ammo. It's also proved to have 100% reliability with M193, Mk 262 and all other .mil 5.56 loads.

If you try to run this same port size with commercial ammo, you will experience some malfunctions with super weak ammo. This is usually steel case Tula & Wolf .223 but can also happen with ammo like PMC .223 if your gun is particularly dirty, etc…

So ALL manufacturers that make a 10.3" or 10.5" barrel for the commercial market decided to enlarge their gas port from mil-spec for increased reliability with ammo commonly used in civilian rifles. Most went with a gas port of around .074 which has been proven over many years and millions of rounds to be great.

DD decided to go way further. They've stated multiple times that their gas port right now is at .081. But many of us have measured (both with calipers and pin gauges) new barrels and seen ports as high as .088. This IS extremely overgassed and will produce malfunctions with a suppressor on. DD JUST commented on TOS not more than a week ago and validated this — and they've done so numerous times throughout the years. You can try to mitigate this with an extremely heavy buffer (Griffin, H3, etc…) and possibly a strong spring, but you still end up with increased recoil, increased parts wear, etc… And sure, you could say that well it's great because you want your rifle 100% reliable with any ammo you throw at it. Except that nobody has ever reported a malfunction with all other manufacturers barrels that are in the .074 - .076 range (LMT, Noveske, BA, Colt, etc…).

It's pretty ridiculous to claim otherwise since there's years of data readily accessible with nothing more than Google and plenty of official statements from the company itself verifying it. Nobody is going to go buy every single barrel in the market just to "show evidence" of something that is already common knowledge. I'd feel pretty comfortable stating that a Geissele SSA-E is a much smoother, cleaner trigger than a standard Colt mil-spec but I'm not about to bust out a video camera and a bunch of tools to "show evidence".

Many (not all) Daniel Defense barrels are overgassed for what they need to be for 100% reliability. This can also decrease reliability if you ever intend on putting a suppressor on that barrel. It's up to you whether that's important or not. Many people run DD barrels over many many years and have 0 problems with them.

Personally, I never intend to run Tula .223 with my rifles and would rather have a rifle closer to mil-spec, that's softer shooting, easier on parts, and that I can run a can on without ever worrying about malfunctions.

I don't believe that anyone was making claims to the contrary, only asking that claims be substantiated.

And you have substantiated your claims. Thank you.

However, it seems obvious to me that it is not, "Common knowledge." Further, it appears that (from the information you have provided) that such issues are restricted to DD's Mk18 clone.

[XD40Colorado]

I agree with it only being the 10.3" barrel - I have a DD MK12 and used to own a V5. Zero issues of any type with either.