16" vs 18" - accurate upper build advice?

[Mo_Zam_Beek]

Now that parts seem to be more available I think I may piece together an upper. I want an accurate do all things relatively well upper but it needs to be sub MOA. I have an N4 with an SB, and an SWS 9" rail. It is consistently slightly more than MOA. The rail is too short. It is reasonably accurate, but not sub MOA.

I know there some potential advantages between rifle length and mid length - but is that really that big of a deal? Also I have read that MV between a 16" and an 18" is only @ 50 fps. I'd rather have the 50 fps, but I am not interested in needless weight nor poor balance; and I do intend to hang an SF 212 off the end of it. I had a Noveseke SPR in a monolithic Vltor but it was a pig with poor balance. I do not not know if that was a function of the mono chassis or the 18" barrel, but I know I don't want that again.

I am willing to spring for a primo barrel - Noveske (are they still good?), Douglas, Krieger, Lilja, Satern, Rock; but the question is - what length?

Upper receiver? A long time ago a MUR with FA was the thing to have - is it still?

Rail? I think I want to go with a keymod system. I think I want a 13" rail - is that about right? Long enough to be practical but not too long, right? Thoughts on brand? Not looking for needless weight either.

Anything else I ought to be thinking about?


TIA

[Koshinn]

Honestly, I'd either go with a bcm ss match upper with kmr and their new upper receiver or a noveske recon with 13" nsr, but both with 16" barrel.

Both receivers are known for accuracy, both barrels are top-notch, and both save weight via their keymod rails.

I personally went Noveske, but that was before the kmr was released.


http://www.bravocompanyusa.com/mobil...16-SS410-KMR13
Plus a bcg and ch of course

Or

http://www.rogtac.com/noveske/novesk...c2-5flute.html

The Noveske is 1500 vs the BCM's $750, but adding a $160 muzzle device, $170 bcg, a $55 CH, a $150 more expensive receiver, and barrel flutes costs extra. But in the end, the BCM is still cheaper, probably the same weight between the lighter rail but heavier barrel, and probably just as accurate.



Edit: I guess I should also ask what your expectations and use for the rifle are. If it's only for the range, I'd get a 20" barrel!

[gt40]

I have a Colt LE6920 M4 that I bought last fall which I killed 3 deer with. I am an accuracy nut and was not satisfied with MOA+ groups. After reading about many different barrel makers I decided on White Oak Armament because of their reputation for accuracy. All of the makers make good barrels, but I wanted to hedge my bet by getting a WOA. It still can be a crap shoot. On 2-10-14 I ordered an 18" varmint upper with a 1 in 7" twist (.223/5.56) and paid extra to have it fluted under the hand guard and on the end of the barrel to save some weight. I was told by WOA that I should get it in the middle of May and it was delivered to my home on 5-15-14. That was a pretty good estimate. After I exchanged the Colt upper with the new one and added the scope, bipod and sling it was perfectly balanced just in front of the magazine well. The length stayed the same because it has no flash hider like the original has. As for weight it feels only a little heavier than the Colt upper. I haven't shot it yet, but am hoping for 1/2" 5 shot or less at 100 yds. with Sierra 69 grain HPBT Match Kings.

OOPS, I also installed a Geissele SSA-E trigger in the Colt.

http://www.whiteoakarmament.com/xcar...cat=261&page=1

I have a Bushnell AR/223 scope with 4.5-18x40mm zoom with Nikon P-SERIES two piece mount which I like very much. It it crystal clear with good contrast and I can easily see my bullet holes at 100 yds. at 18 power.

http://www.sportsmansoutdoorsupersto...arget-ar-scope

http://www.sportsmansguide.com/net/c....aspx?a=993875

[Onyx Z]

The difference between 16" and 18" is about 100fps. It's typically about 50fps per inch of barrel. In the end, an extra inch isn't really worth it (in this hobby anyway). With that, I went with an 18" Rainier UltraMatch Intermediate barrel that I've been more than happy with: consistently puts 5 shots into .5moa. The intermediate gas is somewhat of a hybrid of rifle and mid-length, but the gas tubes can be hard to find sometimes. The only mfgs using intermediate gas on 18" barrels at this time are Rainier Arms and Noveske. In fact Noveske doesn't even offer a rifle gas. The BCM SS410 18" is rifle gas and all of the 16" barrels will be mid-length. However, Noveske did a short run of intermediate gas on 16" barrels closely mimicking the SR-15 gas length. I'm not sure if you can find those anymore, but that would make one sweet shooting rifle.

13" rails provide the perfect length for 14.5" and longer barrels IMO. The NSR or KMR will work and both are light, but if you are wanting the absolute minimum weight, go with the KMR around a 16" barrel. I still like my NSR's, but I really like my KMR. It's unreal how light the KMR is, almost feels like a toy. 7.7oz with all mounting hardware!

I went with a MUR upper receiver since it was a little beefier hoping to squeeze everything out of this barrel. If you are only looking for sub-moa, then BCM's new M4 upper receiever will serve you well and save money.

I didn't see you mention anything of a trigger, so be sure and look into that too. A great trigger can completely change a rifle. Geissele is the only way to go in that respect. SSA or SSA-E should fit the bill perfectly.

In the end, I'm sure you will be happy with either one of those manufacturers since they both both build great, high-quality rifles.

[BrigandTwoFour]

You didn't lay out an intended purpose for the gun, so it gets a bit difficult to really recommend something specific. I pretty much agree with Koshinn. If it's a pure range gun, there's a lot to be said for a 20" musket (I'm learning the joys of such a set up now). If it's more for general use, then a BCM SS410 with KMR rail, Noveske LP 16 with NSR, or i would also add a Rainier Arms Ultramatch 16" with Centurion C4.

Again, it all comes down to what you want to use it for.

[gamewarden]

If you are building this as a SPR type rifle or RECCE type rifle this is what i would recommend.

First, let Wes at MSTN build it for you! He has custom Noveske barrels that you can't get anywhere else (i.e. 18" 3 grove 8 twist with rifle length gas system, 16" 3 grove 8 twist with KAC length gas system). I have the 18" and it is one sweet shooter...been out to 800 on 16" steel with it. Matched with a Vltor A5 sytem and surefire break its a pure joy to shoot. I am also currently having a 16" RECCE type upper being built right now by Wes. He can build it with BCM KMR rails, Geissele rails, KAC, or Noveske rails. He typically uses Young National Match or standard BCG that you can have ion bonded diamond black. He also uses BCM and LMT bolts. Uppers receivers are Vltor MUR's. I believe you can still get just the barrel if that is all you want.

let me know if you have any questions. Wes and MSTN currently do not have a website (don't ask about it). You can check him out on Facebook or just send him an e-mail and he can send you his price sheet.

If this is not what you are looking for and just want a nice rifle to shoot at the range that shoots sub moa a SS BCM with KMR would be a great rifle.

[gt40]

I just called WOA and spoke to Jane. She told me that on my 18" the gas block is located 1" less than the standard rifle length and said that others may call it an "intermediate". I was also told that the chamber is shortened up a little to shortened the distance of the jump which should help with the accuracy.

[Clint]

The intermediate is normally 1.5" shorter than rifle length and an excellent match for an 18" barrel.

I just called WOA and spoke to Jane. She told me that on my 18" the gas block is located 1" less than the standard rifle length and said that others may call it an "intermediate". I was also told that the chamber is shortened up a little to shortened the distance of the jump which should help with the accuracy.

[Onyx Z]

The intermediate is normally 1.5" shorter than rifle length and an excellent match for an 18" barrel.

Yes, intermediate is excellent for an 18" barrel. I actually prefer it to a rifle length gas system. Shoots smoooothhh

[gt40]

The intermediate is normally 1.5" shorter than rifle length and an excellent match for an 18" barrel.

I may be quoting Jane incorrectly. She may have told me "about" 1 inch. I'll call tomorrow to find out exactly how they do it. I also have to ask her what I may need to do to the buffer or spring because of the new upper.