SPR Build, help

[cundiff5535]

Hey guys, I have some extra AR parts laying around and figured... Why not use them, or sell em Since I am missing an SPR, I want to throw one together using what I have but, before I do, I am looking for your help. I own a few carbines and a few bench guns... all good to go and very happy! Since I know how it goes... I figure I should reach out and do it right... Advise and thoughts are appreciated.

First my spare parts:
14" Fortis Rail
Seekins BCG
Seekins Gas Block
Seekins Upper and Lower
2 Stage trigger
Random LPK
LMT Sopmod
Magpul CTR
Magpul STR

What I need:
Barrel
Comp
Bipod
I think that covers it

I am in no rush here so, I figured I would send the bolt to Compass Lake and have Frank cut a Krieger 18" barrel to the Seekins BCG I have laying around? Anything specific I need to have done? Thoughts here?

I have 3 stocks laying around... what works best?

Comp? Collar?? Any parts you wouldnt use out of the stuff I have collecting dust?

All help and advise is much appreciated!

 

[sendit300]

You're right on with using Compass Lake Engineering! Get the M4 feed ramps and matched bolt. I'd use the CTR stock unless you need the battery compartment, or can't get an efficient weld using it. Surefire 556-SFMB works well, but everyone has a favorite. Bipods are few and far between, Harris, Atlas, even seen guys use the Manfrotto tripod w/ attachment. I'd look at selling some stuff and picking up a Geissele trigger and rail. I've become very particular over the years. Good luck and have fun!

 

[jasonfaz]

I'd most definitely look at putting together a rig with a Tactical Innovations ultra light 16.5" w/rifle length gas. I've been very curious how those would shoot compared to the standard SPRs (which are traditionally heavy as shit). That'd be a cool project.

I'd be torn between using an A5 length tube and buffer vs standard carbine length. Depending on where you go there would dictate my stock choice as I prefer running a rifle with the stock fully collapsed in normal shooting positions and adjust LOP as extenuating circumstances dictate. The only stock I've run that fully collapses on an A5 length tube is the STR. If you don't roll with an A5 I'd keep the SOPMOD and sell the rest.

I'd also ditch the Fortis rail and go with a 15" KMR or similar. Using the Fortis handguard it seemed like I was holding a 2x4 rather than the more natural feeling set ups of the NSR/KMR/URX etc.

Let us know what you end up going with....and I'll grab that STR from u if it's mil spec diameter and you end up not needing it.

 

[jasonfaz]

...almost forgot the comp aspect. If you're not planning on suppressing it, it go with the Lantac. That'd be a ridiculous nice set up.

 

[bkw1911]

I'd most definitely look at putting together a rig with a Tactical Innovations ultra light 16.5" w/rifle length gas. I've been very curious how those would shoot compared to the standard SPRs (which are traditionally heavy as shit). That'd be a cool project.

I'd be torn between using an A5 length tube and buffer vs standard carbine length. Depending on where you go there would dictate my stock choice as I prefer running a rifle with the stock fully collapsed in normal shooting positions and adjust LOP as extenuating circumstances dictate. The only stock I've run that fully collapses on an A5 length tube is the STR. If you don't roll with an A5 I'd keep the SOPMOD and sell the rest.

I'd also ditch the Fortis rail and go with a 15" KMR or similar. Using the Fortis handguard it seemed like I was holding a 2x4 rather than the more natural feeling set ups of the NSR/KMR/URX etc.

Let us know what you end up going with....and I'll grab that STR from u if it's mil spec diameter and you end up not needing it.

Tactical innovations or voodoo innovations on the barrel?

 

[jasonfaz]

My bad. Voodoo Innovations on that barrel...

 

[bkw1911]

You make me want to build one now and that lantac is pretty sick.

 

[cundiff5535]

Anyone have thoughts in 18" or 20" barrel?

 

[Gimp]

I always use Daniel Defense's CHF barrels. I did an SPR a short while ago and used an 18" S2W.

 

[Mil.Dot]

Anyone have thoughts in 18" or 20" barrel?

I personally prefer an 18", but I don't need the slight increase in velocity of the 20. I prefer the weight and length savings of the 18. An 18" with rifle length gas is very soft shooting.

 

[fargo007]

I've been shooting a rifle like this in precision comps for ~2 years now. I had a 20" WOA on it with a gemtech sandstorm. The gun is now disassembled waiting for a Hawk Hill 18". Everything you would want to do with this is do-able with the 18 just like the 20 but with less weight and less out front. The velocity is built before the gas port. Once the bullet passes that, there is much less force pushing it.

/Fargo007

 

[Guest]

I have the WOA 16" SS Match 1:7 barrel on my Recce and it shoots lights out. Love the Troy Alpha rail with no bulk but can add rail sections if you want. Also went with Syrac Gen II adjustable gas block, Timney AR Competition 3lb trigger and Young Manufacturing BCG. Im a UBR fan when it comes to stocks on precision rifles but not everyone likes them.

I have both Geissele and Timney and you couldn't go wrong with either.

 

[Steel head]

I like the 18" barrel makes for a very handy AR.
18's with a rifle gas system shoot very nice.
I have a Rainier Ultramatch SPR barrel and am very happy with it.

 

[cundiff5535]

Very good info here... So it looks like 18" spr Compass/Krieger and Lantac break! I know that these barrels come contoured for a "collar". Can anyone bring me up to speed on what this is, are there different manufacturers, where can I buy them, is it compatible with the Lantac break?

Btw, I found a Geissele trigger laying in my spare parts box! Obviously I'll be using that.
Thx

 

[g3ninfinite]

The collar is used to mount an ops inc 12th model suppressor. You don't need it.

 

[cundiff5535]

The collar is used to mount an ops inc 12th model suppressor. You don't need it.

I would still want to add one. The way I understand the barrel, it is contoured with a "ridge" for this collar. I think it would look off if it's not there.

Since I'm in IL, I can not have a suppressor anyway but, I would like it to look correct.

 

[Mil.Dot]

I would still want to add one. The way I understand the barrel, it is contoured with a "ridge" for this collar. I think it would look off if it's not there.

Since I'm in IL, I can not have a suppressor anyway but, I would like it to look correct.

The step in the barrel for the collar is very small and will not look funny without the collar (IMHO). Many 18" barrels with rifle gas have the step.

If you want to make it a Mk12 clone, then you will want the correct rail from PRI or KAC and also the Ops Inc brake not the Lantac.

Your call obviously but just some things to think about.

 

[cundiff5535]

Yeah, since I want to use what I have (Not a fan of some of the MK12 parts) I dont care to call it an MK12. I would rather use the parts I want and have the rifle I want! Let me ask this... can I use the Lantac break and still have a collar on it? Where do I get one at?

Thanks again for the info and... schooling a rookie!

Bc

 

[g3ninfinite]

So you don't want a clone.... But you want to look correct.... You have no idea what the collar is.....but you know you want one.... You have no idea what the step looks like.... But you know you want to cover it up....

 

[g3ninfinite]

Step in barrel...

 

[cundiff5535]

So you don't want a clone.... But you want to look correct.... You have no idea what the collar is.....but you know you want one.... You have no idea what the step looks like.... But you know you want to cover it up....

When you word it like that it sounds kinda silly. When I say "correct" I didnt mean specific to a MK12. I meant correct like the barrel will look wrong. Kinda like a carbine rail with a rifle gas tube, it may look silly. I know what the collar is for at this point, so can I use a collar in conjunction with the Lantac? The collar wouldnt be used... just go on the rifle. If I am starting to sound silly... just say... "Forget the collar". Lol

 

[cundiff5535]

Step in barrel...

^ I see... I guess I should just forget the collar Looks fine without it

 

[g3ninfinite]

Adco sells just the collar. You can use it with any muzzle device just needs to go on prior. Also the lantac has a hellacious muzzle blast if you are shooting prone a lot I would reconsider. For the price of the dragon you can get the ops inc brake and collar combo which is very nice to shoot prone as is much less offensive.

 

[rideHPD]

You can get the contract barrels from Centurion Arms or High Caliber Sales, they shoot lights out. Douglass blanks turned by CLE if I'm not mistaken. And adjustable gas block may be a good idea.