Help me choose my 5.56 SBR Upper - DD or Geissele

[Glassaholic]

Love that movie. Well my English teacher would be very ashamed of me right now

 

[Glassaholic]

Or, maybe he does and is bring both cheeky and mysterious…

No, that was me trying to use big words in the wrong context

 

[Army of One]

I'm partial to 11.5 uppers, and if given a choice, I would probably go with a Colt 11.5 HRT spec upper with the actual HRT contract Colt barrel. Absolute laser.

Outside of that, a URG-I 11.5 upper, but only if it has the Daniel Defense 11.5 barrel.

 

[cruiserweight]

DD just released the RIS III if you’re willing to wait/search to find one. That being said, having spent time behind the mk18 and a Geissele 10.3 gun at work, I prefer the Geissele. As does every one of my coworkers lol.

 

[clcustom1911]

I use a DD Mk18 CQBR upper on a Colt M4a1 lower setup at work. I like it, very reliable with a standard buffer spring and H2 buffer.

 

[Maverick910]

Geissele 11.5

 

[Naaman]

I'm partial to 11.5 uppers, and if given a choice, I would probably go with a Colt 11.5 HRT spec upper with the actual HRT contract Colt barrel. Absolute laser.

Outside of that, a URG-I 11.5 upper, but only if it has the Daniel Defense 11.5 barrel.

Check out Centurion Arms if you haven't already.

11.5in FBI, Hammer Forged Barrel, Carbine

Centurion's hammer-forged barrel process leaves an extremely smooth and consistent surface on the inside of the barrel, that gives it pinpoint accuracy.

centurionarms.com

 

[AngryKoala]

DD just released the RIS III if you’re willing to wait/search to find one. That being said, having spent time behind the mk18 and a Geissele 10.3 gun at work, I prefer the Geissele. As does every one of my coworkers lol.

DD is on crack with their pricing. Hopefully it brings the pricing down on the RIS 2 rail. At least Geisseles tardo pricing gets cut by 20-30% a few times a year. Hopefully Geissele can get their shit together.

 

[Glassaholic]

I’ve had a 14.5 pinned upper before and really liked it. Wanted something smaller (shorter) this time but funny you should mention that because I’ve been in touch with Craddock about a barrel in the 14.5” class and waiting to hear what they may be able to do.

 

[Desert_Racer]

Here’s a 14.7 I just built. The barrel was a 16” CLE Douglas Recon contour, with a little smaller profile past the gas block. I had my local smith cut it down for me. It’s a touch heavy, but balances and handles nicely. I’ll be running a Sig 5.56 SLX-C can on it when it gets out of jail, so it won’t be too unwieldy. I think it will end up being my go to 5.56 rifle for most things.

 

[CaptArab]

I know you are choosing between one of the two but on the off chance you are seriously entertaining building an upper....

I've used 10.3" and 11.5" guns a lot and I have to say I really think a 14"(13.7 - 14.5") is the perfect barrel length. If I was to build anything shorter it would be minimum 12.5". The extra blast, velocity loss, and the fact that you lack enough rail length to support hand grip it without compromising and mounting lights and lasers is limited.

if you're going to change a rail on one of those two uppers and then mount it to a disassociated lower(assumption that you're going to have to tune the buffer now), you're already going through 2/3's of the issues of building an upper.

This is where I'm at, especially with all the legal BS looming.

 

[Coloradocarbine]

Interestingly enough, certain barrel/ammo combinations in 12” range run as fast as they do in 14.5”. So if you’re looking to keep it shorter, keep that in mind too.

 

[TonyTheTiger]

Interestingly enough, certain barrel/ammo combinations in 12” range run as fast as they do in 14.5”. So if you’re looking to keep it shorter, keep that in mind too.

Go on?

 

[Coloradocarbine]

Go on?

One example that you can just watch/listen to. Plenty of threads etc that confirm same thing if you care to dig into it. But In general, yes, you lose a little. Like 50 fps on average. Which is practically nothing. A few different factory loads will still expand out to 300 yards from 11.5”. Our special operations guys run the H&K 416, 10.4” barrels. If it’s good enough for them, chances are it’s good enough for us, lol. Depends on objective. For 250 yards and in, I can’t see what a 14.5-16” gets you other than jammed up in a hallway.

 

[Coloradocarbine]

If you jump ahead to about the 8 1/2 minute mark it will do the 12 1/2 inch Springfield Saint and then immediately afterwards the 14 1/2 inch Daniel defense. The 12 1/2 inch was actually five 5fps faster in the first run. Again there are so many variables. To do an apples to apples comparison you would really need to cut down the same barrel with the different ammo selections. The whole point, is that you can get some pretty decent velocities out of some of the shorter barreled options.

 

[Glassaholic]

For 250 yards and in, I can’t see what a 14.5-16” gets you other than jammed up in a hallway.

Had a visual of a guy with the front of his rifle punched through a section of drywall

I would not be looking for 14.5 to replace a 11.5 or shorter; however, I am thinking of a 14.5 to replace my SPR with 18" barrel. I'd be curious how much of a difference 14.5" makes compared to 18". If I'm looking at an "effective" range of 600 yards and in, and assuming both the 18" and 14.5" offer the same accuracy, then even at 2400fps (for Mk262 77gr SMK) I'm still well above supersonic at sea level at 600 yards. Given that, outside of "energy", what else am I missing?

 

[Glassaholic]

This CQB in a hallway thing fake news. We went through most of GWOT with 14.5" barrels. And And there's likely only one person in this thread that has to worry about CQB.

I've been testing and shooting about a half a dozen 13.9", 14.5", 18", and 16" barrels over the last couple months. You can easily shoot submoa with any of those barrel lengths and you're probably looking at around 2650 for muzzle velocity with 77 grain ammo out of the shorter ones. I think I was getting around 2750 with an 18-in bartlein and that same ammo shot 2,800 in my 20-in white oak. So I don't think you're missing anything in that regard but what you might be missing is how you set that gun up. In order to shoot subminute groups with a small light little AR like that You're probably going to want a bipod on it, and a decently sized scope like a night force NX8. A heavier Magpul PRS type stock helps a little bit too. I noticed it became just a bit more difficult using a lighter more carbine-like Magpul CTR. But a 14.5" barreled AR configured like that just looks fucking dumb IMO. With a suppressor on it You're really not saving that much. The main bulk of a 16 or 18 in barreled gun is still there. It's just a little bit of barrel length. Once you take the bipod off, put your more desired carbine stock on it, make it nice and light, and then put an LPVO on it like a 1 - 10 It's just not as shootable as an SPR style gun. It's kind of why PRS guns are configured the way they are. A 7 lb hunting rifle and a 17 lb PRS rifle are probably, technically capable of the same mechanical accuracy But they clearly perform at distance differently once you figure in the shooter. The other thing to consider is how these different barrels are going to be gassed. I have found 16 and 18 in mid length barrels to be more unpleasant than 13.9 in mid-lengths or 20-in rifle length. An intermediate length 16 or rifle length 18 might make their recoil a bit smoother. None of that is a factor If you've got the gun bagged in, on a bipod, out of a flat range, focusing and extracting all your marksmanship fundamentals. But as soon as you get positional in my opinion it makes a huge difference. My 20" is heads and shoulders more accurate and smoother than all the others. But I am really interested in trying a 16" Rainier Ultra Match with an intermediate gas length. And you don't actually gain any length if you direct thread a can on a 16-in gun versus using something like a keymo on a pinned brake adapter on a 14.5. In fact, it is lighter. I direct thread my Dominus on a 16-in barrel and then have pin and welded keymo brake on my 14.5" and 13.9 in barrels and I'm using a rex silentium mg7 with a keymo adapter in it. That combination is actually heavier.

My preference if I am trying to do some sort of SPR type gun is either 16 or 20 in. 18" is just this weird half measure length that doesn't seem to have a lot of advantages.


14.5"
View attachment 7950494
16"
View attachment 7950495
18"
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20"
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The only people running and gunning for speed in the civilian world are three gun shooters and they are all using 16 and 18 in blastomatic carbines. They don't seem to have any issues with their CQB, lol.

Good point on recoil and how smooth everything is with the longer barrel and gas

 

[greg1147]

Geissele URG-I , 10.3" Variant, 5.56MM
Griffin Recce waiting for the RC2

 

[clcustom1911]

I was using a 20" M16A4 for "cqb" in 2004-2007. Would have loved a 14.5. Plus.. when you suppress a 10.3, it magically turns into a 14.5-ish length barrel.

 

[Naaman]

I was using a 20" M16A4 for "cqb" in 2004-2007. Would have loved a 14.5. Plus.. when you suppress a 10.3, it magically turns into a 14.5-ish length barrel.

Lol... Reminds me of a running gag at work:

"I waited 12 months for the $200 tax stamp to be approved for my 10" mk18 for when I have to do CQB around the house because my 16" is too unwieldy. When I got out to the range, it was too loud, so I bought another $200 tax stamp and waited another 12 months to get a suppressor to quiet it down. The extra length isn't bad at all: just about what a 16" would be unsuppressed."

 

[clcustom1911]

Lol... Reminds me of a running gag at work:

"I waited 12 months for the $200 tax stamp to be approved for my 10" mk18 for when I have to do CQB around the house because my 16" is too unwieldy. When I got out to the range, it was too loud, so I bought another $200 tax stamp and waited another 12 months to get a suppressor to quiet it down. The extra length isn't bad at all: just about what a 16" would be unsuppressed."

My KAC 16" suppressed is a dream. Quiet and very low recoil. Amazing.

 

[BCP]

I like the look of the geissele handguards, would do one of those with an 10.5 or 11.5 barrel. Bonus points if it's the bronze looking FDE finish.

 

[Coloradocarbine]

Decide anything glassaholic?

 

[Glassaholic]

Decide anything glassaholic?

After much agony and internal debate I decided on the DD Mk18, I almost went with the Geissele for MLOK and 11.5” length but after mounting everything up the RIS II rail really grew on me.

 

[Coloradocarbine]

Looks sharp. There really was no wrong answer.

 

[Glassaholic]

Thank you to everyone who contributed here and in PM, appreciate you all helping me out.

 

[corey4]

your tbac is rated for 11.5 and above

 

[Glassaholic]

your tbac is rated for 11.5 and above

Way to rain on my parade But seriously, that suppressor (Ultra 5) is from my 300BLK and I was intending on picking up a Dominus SR; however, you do bring up a good point that I will need to wait, God knows how long, for Brandon's ATF to approve my privileged use stamp once I decide on the Dominus.

I was about to put my Geissele up for sale, but now you have me thinking twice about my decision to got with the DD 10.3...

 

[corey4]

if you like the mk18 rail, pick up an 11.5 barrel. it won't look as cool cuz of the gap between the can and hand guard, but it's an option.

 

[corey4]

you'll have to pull the hand guard apart anyways for an agb, so you can use that time to put in a 11.5.

i prefer my 11.5 DD over my mk18 10.3

 

[Glassaholic]

Helps to know people, just found a TBAC Dominus SR and hoped won’t have to wait to long with efile.

 

[Glassaholic]

you'll have to pull the hand guard apart anyways for an agb,

I’ve always understood the DD 10.3 to be ported for both suppressed and unsuppressed use without an AGB, have you found different?

 

[S197]

Way to rain on my parade But seriously, that suppressor (Ultra 5) is from my 300BLK and I was intending on picking up a Dominus SR; however, you do bring up a good point that I will need to wait, God knows how long, for Brandon's ATF to approve my privileged use stamp once I decide on the Dominus.

I was about to put my Geissele up for sale, but now you have me thinking twice about my decision to got with the DD 10.3...

Since you decided on the 10.3, the best suppressor for that upper (currently) is the rc2.

 

[houndog]

I’ve always understood the DD 10.3 to be ported for both suppressed and unsuppressed use without an AGB, have you found different?

Own a DD with 10.3" barrel. Run it with a Dead Air Sandman S and never found the need for an AGB (and I shoot lefty, so I'm more sensitive to gas blow back). I think I have a Geisele spring and an H2 or H3 buffer and the gun runs like a top shooting mostly XM193 or PMC X-TAC.

 

[corey4]

I’ve always understood the DD 10.3 to be ported for both suppressed and unsuppressed use without an AGB, have you found different?

i have the huge gas port on my 10.3 from 10 years ago. i forget the size and i never pin gauged it. judging from what orhers have said, my gas port is from the over sizing days according to the timeframe of when i bought it. i have 2 dd mk18 factory srbs that came with the magpul furniture and metal dust cover.

 

[clcustom1911]

if you like the mk18 rail, pick up an 11.5 barrel. it won't look as cool cuz of the gap between the can and hand guard, but it's an option.

Even with the DDM4 handguard and RC2 on my LMT 10.3 there's a slight gap, but whatevs.

Much LMT, potentially not poor, am beer.

 

[clcustom1911]

I’ve always understood the DD 10.3 to be ported for both suppressed and unsuppressed use without an AGB, have you found different?

0.070" or 0.072" works very well with M855 ammo and H2 buffer. Unsuppressed sends casings go out at about 4 o'clock year-round. Suppressed (RC2) sends them at about 2-3 o'clock.