Help me build a SPR upper

[terrance250]

Wanting to put a SPR type upper together for shooting coyotes & punching paper.

So far the only thing I have in mind to get it started is a WOA 18" SPR match barrel with a headspaced bolt, but haven't decided weather to go with the mid length or rifle length gas system. I'm leaning towards the rifle length, any suggestions?

Can I get away with a standard upper & bolt carrier to go along with this barrel, or are there better options out there for increased accuracy?

I haven't even started looking at gas blocks,rails,or flash hiders/brakes yet.

Any help/ideas will be appreciated.

 

[Ed-G]

Re: Help me build a SPR upper

This is what went with for my SPRish upper:
-18" Noveske barrel w/intermediate length gas system and 1" gas block.
-DD Lite rail forgot the length but just covers the gas block.
-Bought a Young NM Chromed bolt and carier but ended up using an LMT.
-A2 flashhider
-Upper receiver from Bravo Company.
-Lower receiver from Noveske.
-Geissele DMR trigger.
-Stock has varied with time but currently sports a Magpul ACS.
-Magpul MIAD Grip.

18" WOA are good barrels and I think the preference is rifle length gas system. The two parts that make an AR accurate is the barrel and trigger. For a rail I would suggest a smooth one that you can add rail segments to if need. I am building a piston AR with a 16" mid-length barrel. I'm going to give the Samson Evolution rail a try, its inbound now.

I came close to going the billet route on uppers and lowers but decide against it as I read to many stories of fit issues. For Christmas the Wife and Son got me a matched upper and lower from Noveske, very nice!

 

[USACS]

Re: Help me build a SPR upper

The upper receiver should be dictated by the type of receiver extension tube you attach. If you plan on running a carbine tube, you should be getting an A4/N4/M4 spec upper that has the extended M4-style feed ramps. If you plan on running a fixed rifle-length tube with fixed buttstock (such as A2 or Magpul PRS), you can use a standard A3 spec upper (or you can use an M4 spec one too).

I would highly recommend you look into a VLTOR MUR (Modular Upper Receiver) w/ forward assist. Rainier Arms sells them at a very good price. The VLTOR MUR is probably one of the best upper receivers I've ever seen and used in my AR builds. It's superior to every forged receiver, and is equal-to or better-than optional billet receivers.
Otherwise, if you want to stick with forged receivers, go with a company that will have good quality control, like Noveske, Daniel Defense or Armalite. For billet uppers, consider POF or Mega.

For gas system, if you run a carbine extension tube, I would recommend a mid-length/intermediate gas system. If you run fixed rifle tube, go with the rifle gas system. You have to basically plan the whole build out before implementing it.
And FWIW, WOA barrels are amazingly accurate. Good choice there.
Make sure to use a solid forearm like a Troy, PRI, Daniel Defense or JP.

 

[nefarious79]

Re: Help me build a SPR upper

Rifle length is way to go, I have 20in from WOA with the matched bolt. Only other thing to do for accuracy is free float the barrel and lap the receiver face. Surprisingly the Mega upper receiver I chose for my build looked like it really needed it you can also bed the barrel extension by using red loctite and putting a little extra torque on the barrel nut. I talked to John at WOA, I know they work with the AMU and their rifles speak for themselves at Camp Perry.

 

[terrance250]

Re: Help me build a SPR upper

Thanks for the replies thus far.

Looks like I'll go with the rifle length gas 18" WOA. If nothing else it should cycle smoother.

After looking around last night I've got some more ideas on what to add to the upper. If the funds allow it I'm going to go with a Larue 12" forearm. Looked around at uppers as well, and liked the price and looks of the the Noveske N4 Upper.

Now I just need to figure out what bolt carrier, gas block, & muzzle device I want to use. At this point I'm leaning towards a brake over a flash hider, but I'm still not sure.

 

[BasraBoy]

Re: Help me build a SPR upper

Planning the same:

18" WOA SPR with headspaced bolt/rifle length
VLTOR VIS 3 monolithic upper
AAC 51T Brake
Youngs Manufacturing NM BCG
KAC 200-600m flip up rear sight
NG 2.5-10 x 24 Compact in Larue QD mount
Atlas V8 on ADM or Larue QD mount
PRI Gas Buster CH with Combat Latch

To be decided:

Low profile clamp on GB + upper rail mounted KAC front flip or ARMS #41 GB/Sight


No pins or set screws!!

 

[5RWill]

Re: Help me build a SPR upper

So far for my upper i have this. Of course this is a MK12 Mod 1 clone.

BCM rifle length gas tube
BCM 18" SPR SS410 Ionbond coated barrel
BCM MK12 Collar and break
BCM BCG and charing handle
KAC RAS rifle length rails
Vltor Upper receiver
Vltor Low Profile gas block

 

[BERTMAN77MK2]

Re: Help me build a SPR upper

Krieger, Satern, Noveske, WOA or Compass barrel
Larue, Vltor, Mega, or Seekins upper/lower
Badger Ord gas block
Giess, or AR Gold trigger
PRS or UBR buttstock
DD, Troy, Vltor, Samson, or Larue forearm rail
Young, BCM, or 1 of the enhanced BCG
SUREFIRE BRAKE

 

[Cerebus]

Re: Help me build a SPR upper

For a mid-length gas system, what length rail would be best? I'm thinking I want it to end at the gas block.

 

[terrance250]

Re: Help me build a SPR upper

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Cerebus</div><div class="ubbcode-body">For a mid-length gas system, what length rail would be best? I'm thinking I want it to end at the gas block. </div></div>

I have a Troy 9.0" that stops just before the gas block on a mid length.

 

[terrance250]

Re: Help me build a SPR upper

WOA 18" SPR rifle length gas system & Vltor upper have been ordered. I can't wait to start putting this thing together.

I've got another rifle I need to sell so I can get all the parts I want to complete this build. With any luck maybe I can have it up & running by spring time.

 

[Turk]

Re: Help me build a SPR upper

In Indiana: http://www.highcalibersales.com/Site/Home.html
just sayin

 

[BaileyMoto]

Re: Help me build a SPR upper

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">In Indiana: http://www.highcalibersales.com/Site/Home.html
just sayin

</div></div>

+1

 

[mjh30]

Re: Help me build a SPR upper

Another +1 for Kevin at http://www.highcalibersales.com/Site/Home.html

 

[bcw1284]

Re: Help me build a SPR upper

If you ordered it rifle-length, then you won't be able to use the 9.0 rail without it looking stupid. You will need a 12.0 or longer... the "spec" correct one for an SPR is a KAC free float unit. You could however use a LaRue or DD or something else if you don't care about accuray to the military SPR spec.

FWIW, I run a 14.0 daniel defense on mine.

 

[YO_Doc]

Re: Help me build a SPR upper

WOA makes a great barrel you will be happy with it. I was planning to use one for my SPR and then I fell upon a Noveske rifle length 1:8 twist 18" barrel.
The rest of my rifle is an LMT lower with a SOPMOD stock and @ stage trigger, LMT Enhanced M16 BCG and an H1 buffer, Vltor MUR upper, Larue 13.2 rail, Nightforce 2.5-10X24 in a Larue mount, MIAD grip, AAC SPR/M4 mount/flash hider, SPR/M4 can, padded sling.
It took a few trips out to get the timing right for really hot days. The good news is she still it timed right in extreme cold.
She is a great rifle. If I were to build her again today I would dimple the barrel and go with the 12.0 rail to shave some weight as she is a bit heavy after 24 hours of hauling her around.

She shoots great from -20F to well over 100F.
I just flat out love the SPR system, it is m goto rifle

 

[terrance250]

Re: Help me build a SPR upper

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bcw1284</div><div class="ubbcode-body">If you ordered it rifle-length, then you won't be able to use the 9.0 rail without it looking stupid. You will need a 12.0 or longer... the "spec" correct one for an SPR is a KAC free float unit. You could however use a LaRue or DD or something else if you don't care about accuray to the military SPR spec.

FWIW, I run a 14.0 daniel defense on mine. </div></div>

I was just answering another posters question when referring to the length of a handrail for a mid-length. I'm having a hard time deciding which handrail I want to use on this build, but I'm leaning towards the 12" LaRue.

So far I've received a Vltor upper with forward assist, the WOA SPR barrel, and a Vltor gas block.

Already ran into an issue with the gas block being .006" smaller than the barrel. Called the guys at WOA and they are having me send my barrel back along with the block so they can properly fit them. They were great on the phone and seemed like they would go out of their way to make me happy. Although I don't know how well the barrel will shoot yet, WOA has already impressed me with their customer service.

 

[Moof]

Re: Help me build a SPR upper

Why are folks goin with the rifle length gas in a 18" spr barrel? When I ordered mine from WOA, John said that the mid is better to go with. Must not be to bad because I have yet to have any issues with it. Also with the Troy TRX rifle length rail make it look great and handles even better with the less weight.

 

[bcw1284]

Re: Help me build a SPR upper

My SPR has the same upper you just ordered, I really like it. I have a noveske barrel on this one, but had I not gotten a great deal on it I would have used the same barrel you did. WOA is a good outfit, so the good CS doesn't surprise me.

Are you going to use the mk12 collar on yours? If so you should have WOA fit that too while they have the barrel.

As far as the rail goes, the LaRue is a very nice unit. I prefer Daniel "Lite" rails just because I have several and am used to them, but that is no reflection on other rails' quality. The free float KAC is in the same price ballpark as DD. There are other choices as well, some I have experience and some I don't. I can tell you that having had a troy MRF, I won't own one of those again (picatinny out of spec on one side, attachments fell off).

Unless you are building to mil specs, then choose what you like and what fits your style & wallet best.

 

[bcw1284]

Re: Help me build a SPR upper

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Moof</div><div class="ubbcode-body">Why are folks goin with the rifle length gas in a 18" spr barrel? When I ordered mine from WOA, John said that the mid is better to go with. Must not be to bad because I have yet to have any issues with it. Also with the Troy TRX rifle length rail make it look great and handles even better with the less weight.</div></div>

Because 18" + rifle length gas tube is the spec for the military mk12, and as such it is the "benchmark". I don't think it makes a whole lot of difference honestly.

btw- my noveske is a midlength and shoots great.

 

[5RWill]

Re: Help me build a SPR upper

I'm in the process of building an SPR MK12 Mod 1 clone. But i will also be using the Vltor Mur receiver. Really like the price on it for 189$ it's unbeatable. My specs:

BCM BCG&Charging handle
BCM Rifle length gas tube
BCM MK12 Break and collar (Ops inc if BCM isn't available)
KAC RAS rifle length rail system
Vltor Low Profile Gas block
Vltor Mur upper receiver
Douglas SPR 1:7 barrel.

 

[terrance250]

Re: Help me build a SPR upper

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Are you going to use the mk12 collar on yours? If so you should have WOA fit that too while they have the barrel.
</div></div>
I considered going the Ops Inc route, but have decided to go with a YHM Phantom 7.62 can that will ride on several of my guns.

As soon as I get this rifle completed I'm sending off my 700 barrel in .308 to be threaded. This project is gonna end up costing me way more than I initially planned