I’ve got a 20 inch m16a4 type rifle with a bipod and Nikon scope with a a2 stock and I’m looking to build a cqb/primary type rifle with my other complete lower. I just can’t decide on if I want a factory Daniel defense 10.3 barrel with a mk18 ris II rail or a factory 14.5 Daniel defense barrel with the m4 ris II rail. Either way I’m sbring the lower and looking for which you all think would best compliment my 20 inch and your reasons why. Do you find that your 10.3 dd ar’s are just as reliable? Thank you all for the help in advance.
No help huh?
I built an 11.5 inch with a BCM barrel. It cycles every bit as reliably as my 16 inch mid-length. I chose 11.5 inches because I believe it to provide the best combination of short barrel length and reliable cycling due to the fact that that 1 inch in extra length adds a substantial increase in dwell time, thus more reliable cycling. If you graph it out, 11.5 is the sweet spot. I chose BCM also because they seem to have a better handle on gas port size. DD, on the other hand, has had some issues with that. Or so I hear.
What do you mean “compliment” your 20"?
Do you want them to LOOK similar?
Do you want them to have the same components?
If you want a “cqb/primary” rifle, you want to choose components based on your perceived need. 11.5" barrels are about as far as most people want to go in regards to fragmentation range and suppressor wear.
Are you going to be taking the gun to classes? Just plinking? Home defense? HD guns need to have a light, sling and red dot as a minimum.
By compliment I mean I have the 20 for long range and I want something to fill the cqb role. Yes to all the above. I’m not going with an 11.5. The fragmentation range between the 10.5 and 11.5 is less than 40 yards difference and I’m not running a suppressor. It will have an inforce mounted light and a lucid hd7 gen 3 red dot. Reliability is my only concern with going with a barrel length that low but I’m starting to figure out that all of the top manufacturers have figured them out. I do plan on taking a few carbine classes as well.
It can not be argued that all things equal, the 11.5 is going to be more reliable than the 10.x, but all things are not equal.
Personally I have a 12.5, it imo is identical to an 11.5 that has the rail I want / fits me better. I see a lot of people that get 10.5s later get 11.5 or 12.5s.
Agree. If no suppressor, the 11.5 will run better.
Pardon my ignorance. What does this even mean?
The fragmentation range between the 10.5 and 11.5 is less than 40 yards difference and I’m not running a suppressor.
11.5 fragments 40 yards longer range than 10.5 on average.
And I’m not running anything other than 14.5 or 10.3/5. Just my preference. I know a couple guys with 10.5 ar’s and they have been reliable after they found which buffer needed to be run in there rifle. For instance I’ve got a friend running an H, one running H2, and another an H3. All running reliable.
Never mind. Good luck with all that.
I don’t have an 11.5", but my 10.5" Noveske, without suppressor, has run probably 3.5k rounds so far with only magazine-related issues. I’ve used 69 gr FGMM, 62 gr Federal bonded soft point, Federal XM193, Federal XM855, PMC Bronze .223, Hornady TAP 55gr, Hornady TAP 75 gr, and Wolf steel cased hollow point .223 without any issues and without changing spring (springco blue) and buffer (H3).
I don’t know how much better than “no issues” you can really get?
Ok, you run 3.5k a year. Do you run it wet? Muddy? Do you run it at -20ºF with wolf ammo? How about when it’s 200ºF after sitting in the sun? Then run all those with a suppressor. Then run all those dirty, no lube, add in a bad mag etc etc etc
The thing about “I have a 10.5 and it’s 100%” is that it’s been 100% FOR YOU. Change one of a million variable and you could have stoppages where a similar gun in 12.5" won’t. Everything comes down to a margin of error. Even slightly longer barrel guns have a larger margin (in theory). The reason shitty ARs come way overgassed is to increase this margin as large as possible so they never hear back in warranty or tech support.
Can a 10.5" run great, of course it can! Would an impossibly identical 11.5" run just as great but with a tiny bit more margin to tolerate different conditions? It should.
The 10.5" imo is fine, but 11.5" in theory has benefit for only 1" unnoticeable inch of length increase. 12.5" imo is pretty much the same except imo it allows a wider and better for my build selection of handguards. So, given 8" 300blk and what that can do in such short barrel length, I think 11.5"-12.5" is about the shortest 556 I would choose.
That said, people are running their 10.5" with no practical issues in reliability. Indisputable they are harder on suppressor erosion but that’s a different topic.
I chose an LMT 10.5" upper for HD and CQB for three reasons. First, both uses are for short enough range that useful length trumps dwell efficiency. Second, the military found it good enough to issue. Third, at around $500 bucks it’s a steal.
Putting a suppressor on increases back pressure (which is the point of “dwell time”) far more than 1" of extra barrel length will. So when running suppressed, the reliability differences between 10.5 and 11.5 is essentially a wash. The only differences then is muzzle velocity (fragmentation range for FMJ rounds and range at which the round goes subsonic, neither of which should matter much for the intended use of a 10.5 or 11.5 rifle) and suppressor erosion. Suppressor erosion is why I run a brake on my 10.5, to act as a sacrificial blast baffle.
And no, I don’t run it muddy or at -20F or 200F, it doesn’t get that hot or that cold in Oklahoma. Although the barrel definitely gets to over 200F.
I’ve never cleaned my 10.5" gun besides running a bore snake through it every couple of range sessions. All I do is drop some lubricant in every so often. Not even a lot, just a few drops here and there. I have run it at around 32F and ambient temperature of 105F without problems.
If a 1" increase over 10.5" is worth it for more unsuppressed reliability and fragmenting range, why not go 12.5"? Why not go 13.7"? Why not go 14.5"? Why not go 16"?
In my opinion, if you’re going to SBR a 5.56mm, get a 10.3-5". 10.3-5" is the shortest barrels most companies will warranty their suppressors on. It also runs the common carbine-length gas tube and can run a carbine-length rail and front sight, or it can run a mid-length FF rail with low profile gas block and leave enough room for a suppressor to mount. Any longer and I’d just as soon step up to a 14.5" pinned or 16" mid gas gun. Again in my opinion, saving 2" going from 14.5 to 12.5 isn’t worth $200, federal registration, and limiting how and where you travel. Saving 4" is better. Saving 6" and getting an 8.5" 300BLK upper is definitely worth it.
Yes, I’m sure there are a lot of people that are running 10.5 inch barrels from a lot of manufacturers unsuppressed and they cycle just fine. If one buys a Noveske SBR, it’s a pretty good bet that it will run great. They’re a quality manufacturer. I was under the impression that the OP was going to rebuild a 20 inch rifle into an SBR with an aftermarket barrel.
No I’d be going with a Daniel defense barrel of I went 10.5 or another reputable company for 10.5. I never expressed at all that I was cutting down a 20".
Re-read my post on margin of error. Do you want to select a weapon that is designed to run on the bare ragged edge of working for reliability (while doing so very well under ideal conditions) and suppressor erosion, or do you want a little buffer room for unknown-unknowns?
Right. That’s what I said. Aftermarket barrel. Who thought you were cutting one down?
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If its bare edge of reliability than why would the military and other govt agencies select it for people like special forces? I think you just prefer the 11.5 platform and want to find a reason why it shouldn’t work. When I was in Afghanistan we work with a group of marines with 10.3s and not one of them had problems with them in the field. I was issued an m16 and always had problems with it.
Where is your proof that 10.5" ARs with proper gas ports “run at the bare ragged edge of working for reliability?” As far as I’m concerned, 14.5" middys “run at the bare ragged edge of working” in my experience. They have given me far more problems than my 10.5".
You say I’m a sample size of one that hasn’t tested all variables. Fair enough. Where are your tests that prove your assertions? And what about all the mk18s issued to Navy and Marines? If they were on the bare ragged edge of working, I think they would have found that edge by now, surpassed it, and discarded the system as unreliable.