Pick apart my SPR build please

[ModestMarksman]

I think I have finally figured out my SPR build and I just wanted to ask if there are any parts you would change. Currently waiting on a Scionics NP3 BCG so that I can send it off to CLE to match to a barrel.

Build List

CLE 18" Bartlein MK12 barrel (Unless someone convinces me to go Krieger)
Scionics NP3 BCG
Radian Builders kit (Will a 14 inch rail be to long to run a OCM5?)
Geissele SSAE
Radian Raptor SD
Radian Talon
OCL Flash hider and collar
Vltor A5H2 buffer with Sprinco Green spring
Vltor Buffer Tube
OCM5
ATACR 4-16
Area 419 ARCA rail

Any recommendations for gas tubes and gas blocks?

Anything you would change? Im mainly going with a Radian builders kit because I can buy one straight from a distributor and I know they make quality shit, though I do like the look of the G$ Mk16 rail better. Would it be beneficial to go with some sort of thermal fit upper or would it not make that much of a difference?

Also thoughts on Apache Rifle Works for building it? I would rather pay someone to do it right than have to fuck with it myself, especially considering my fingers have the dexterity of a dead person.

TIA

 

[Hoody2shoes]

People like to think thermal fit is more accurate but I've never actually seen supporting data.

What do you need out of a gas block?

 

[RTH1800]

Cool rifle but it has little in common with a Mk12 SPR.
Nothing wrong with your build at all. No need to bring SPR into it.

 

[corsairpilot62]

not a clone, but shaping up to be a good rifle. I recommend the Geissele bomb proof gasblock if looking for a low profile. Or the PRI with folding front sight.

I have both Kreiger and Bartlein barrels on bolt guns. Both shoot extremely well. Both put the next round through the same hole. (Honestly, i thought i sucked and went off paper. Switched to steel to see what was happening)

All my ARs (even “clone” builds have the ssae-x trigger best damn trigger ive messed with on ARs

As far as builders. LRI will probably help you out. TBA will, (super long wait times on all projects though) and many more that i can’t think of at the moment.

 

[corsairpilot62]

Oh and Pics when done!

 

[ModestMarksman]

Cool rifle but it has little in common with a Mk12 SPR.
Nothing wrong with your build at all. No need to bring SPR into it.

I know it isnt a clone, the only thing even similiar is the can. What would you call a purpose built accurazied AR pattern rifle if not a SPR?

People like to think thermal fit is more accurate but I've never actually seen supporting data.

What do you need out of a gas block?

Just for it to work. I dont know much about gas blocks and was wondering if anyone had recommendations or if it was worth doing shit like adjustable blocks etc. The main goal is reliability then accuracy that way I can shoot 6 moa groups at 100 yards at the indoor range.

 

[ModestMarksman]

not a clone, but shaping up to be a good rifle. I recommend the Geissele bomb proof gasblock if looking for a low profile. Or the PRI with folding front sight.

I have both Kreiger and Bartlein barrels on bolt guns. Both shoot extremely well. Both put the next round through the same hole. (Honestly, i thought i sucked and went off paper. Switched to steel to see what was happening)

All my ARs (even “clone” builds have the ssae-x trigger best damn trigger ive messed with on ARs

As far as builders. LRI will probably help you out. TBA will, (super long wait times on all projects though) and many more that i can’t think of at the moment.

Who is LRI? Also definitely will add pic when its done.

 

[corsairpilot62]

Who is LRI? Also definitely will add pic when its done.

Longrifles Inc. And tba is Texas Brigade Armory.

 

[Bumblescrub]

Not the hugest fan of Radian stuff except for their charging handles tbh. That builders kit seems pretty damn overpriced even compared to some of the other ambi receivers that are arguably better. Also I personally think they're kind of ugly and look bloated compared to even regular milspec.

If you're fine with a milspec receiver set you could do the Primary Arms Expo Arms upper and lower made by Zev/Mega which are top notch or either ADM M4 or UIC lowers from Bevan Ballistics if you want ambi. The ADM lowers also have actual ambi bolt hold open + release unlike the Radian which is just ambi bolt release afaik.

Not the biggest fan of G$ except for their triggers, but the MK16 looks so much better than the Radian rail. I also really like the Mk4 with the pic rail sections at the end as well. Another option are drive lock rails from either Icon Defense or SOLGW. I've been told that Drivelock rails have one of the most solid lockups for pretty much any rail short of a monolithic upper with included anti rotation tabs for mil spec uppers. Larue also currently has 12" free float quad rails if you wanna go for a Mk12 mod 1 vibe since the KAC FF RAS's are pretty much unobtanium at this point.

IIRC, according to D.Wilson who does alot of barrel cutting and profiling for the Ops Inc/OCM5 cans, the minimum clearance needed from barrel to handguard for it to fit properly is 3.1" so anything shorter than 15" should be good to go.

Personally I don't like adjustable gas blocks. They have a tendency to eventually carbon lock in place, turning them non-adjustable and I don't have the greatest confidence in them with regards to long-term reliability in even basic field conditions. I'd rather keep the gas system simple with a basic low-pro and tune with buffer and spring weights before messing with an AGB. BRT EZ-Tune gas tubes are a pretty popular option and are basically just gas tubes that come in different gas port sizes so that would be a good option with just a basic low-pro gas block if you have a pretty good idea of how much you'll be shooting suppressed/unsuppressed along with what sort of ammo you'll be shooting. That being said, Springco Green + A5H2 is a pretty standard setup so really I'd expect you to be fine with just any standard gas block and tube.

 

[Sgt of Arms]

CLE makes some good 223 barrels so you will be fine there. Bartlien makes the best blanks that I have used and tested. The radian set I think is over priced and doesn't add anything besides looks and ambi. I would go with a forward controls safety, they are a lot smoother and better fitting safety. The G trigger you will like a lot. As for gas block look at slr. Gas tube just order one from WOA.

 

[ModestMarksman]

Not the hugest fan of Radian stuff except for their charging handles tbh. That builders kit seems pretty damn overpriced even compared to some of the other ambi receivers that are arguably better. Also I personally think they're kind of ugly and look bloated compared to even regular milspec.

If you're fine with a milspec receiver set you could do the Primary Arms Expo Arms upper and lower made by Zev/Mega which are top notch or either ADM M4 or UIC lowers from Bevan Ballistics if you want ambi. The ADM lowers also have actual ambi bolt hold open + release unlike the Radian which is just ambi bolt release afaik.

Not the biggest fan of G$ except for their triggers, but the MK16 looks so much better than the Radian rail. I also really like the Mk4 with the pic rail sections at the end as well. Another option are drive lock rails from either Icon Defense or SOLGW. I've been told that Drivelock rails have one of the most solid lockups for pretty much any rail short of a monolithic upper with included anti rotation tabs for mil spec uppers. Larue also currently has 12" free float quad rails if you wanna go for a Mk12 mod 1 vibe since the KAC FF RAS's are pretty much unobtanium at this point.

IIRC, according to D.Wilson who does alot of barrel cutting and profiling for the Ops Inc/OCM5 cans, the minimum clearance needed from barrel to handguard for it to fit properly is 3.1" so anything shorter than 15" should be good to go.

Personally I don't like adjustable gas blocks. They have a tendency to eventually carbon lock in place, turning them non-adjustable and I don't have the greatest confidence in them with regards to long-term reliability in even basic field conditions. I'd rather keep the gas system simple with a basic low-pro and tune with buffer and spring weights before messing with an AGB. BRT EZ-Tune gas tubes are a pretty popular option and are basically just gas tubes that come in different gas port sizes so that would be a good option with just a basic low-pro gas block if you have a pretty good idea of how much you'll be shooting suppressed/unsuppressed along with what sort of ammo you'll be shooting. That being said, Springco Green + A5H2 is a pretty standard setup so really I'd expect you to be fine with just any standard gas block and tube.

Not the hugest fan of Radian stuff except for their charging handles tbh. That builders kit seems pretty damn overpriced even compared to some of the other ambi receivers that are arguably better. Also I personally think they're kind of ugly and look bloated compared to even regular milspec.

If you're fine with a milspec receiver set you could do the Primary Arms Expo Arms upper and lower made by Zev/Mega which are top notch or either ADM M4 or UIC lowers from Bevan Ballistics if you want ambi. The ADM lowers also have actual ambi bolt hold open + release unlike the Radian which is just ambi bolt release afaik.

Not the biggest fan of G$ except for their triggers, but the MK16 looks so much better than the Radian rail. I also really like the Mk4 with the pic rail sections at the end as well. Another option are drive lock rails from either Icon Defense or SOLGW. I've been told that Drivelock rails have one of the most solid lockups for pretty much any rail short of a monolithic upper with included anti rotation tabs for mil spec uppers. Larue also currently has 12" free float quad rails if you wanna go for a Mk12 mod 1 vibe since the KAC FF RAS's are pretty much unobtanium at this point.

IIRC, according to D.Wilson who does alot of barrel cutting and profiling for the Ops Inc/OCM5 cans, the minimum clearance needed from barrel to handguard for it to fit properly is 3.1" so anything shorter than 15" should be good to go.

Personally I don't like adjustable gas blocks. They have a tendency to eventually carbon lock in place, turning them non-adjustable and I don't have the greatest confidence in them with regards to long-term reliability in even basic field conditions. I'd rather keep the gas system simple with a basic low-pro and tune with buffer and spring weights before messing with an AGB. BRT EZ-Tune gas tubes are a pretty popular option and are basically just gas tubes that come in different gas port sizes so that would be a good option with just a basic low-pro gas block if you have a pretty good idea of how much you'll be shooting suppressed/unsuppressed along with what sort of ammo you'll be shooting. That being said, Springco Green + A5H2 is a pretty standard setup so really I'd expect you to be fine with just any standard gas block and tube.

Main reason for going Radian is I get dealer pricing and don’t have to pay any tax for them which gets the cost down quite a bit. My other thought is to throw an ADM upper on an ADM lower since I already have the ADM lower.

I’ll probably just go with a regular gas block and tube if there isn’t any solid reason to spend the extra cash.

Definitely going to get a legit MK12 clone one day when I finally get a KAC rail or if for some reason they become obtainable easily.

 

[ModestMarksman]

CLE makes some good 223 barrels so you will be fine there. Bartlien makes the best blanks that I have used and tested. The radian set I think is over priced and doesn't add anything besides looks and ambi. I would go with a forward controls safety, they are a lot smoother and better fitting safety. The G trigger you will like a lot. As for gas block look at slr. Gas tube just order one from WOA.

Are there any downsides to Radian as far as precision goes? Im able to get the builders kit for $800 out the door which doesnt seem to bad for a rail, upper and ambi lower

 

[Bumblescrub]

Main reason for going Radian is I get dealer pricing and don’t have to pay any tax for them which gets the cost down quite a bit. My other thought is to throw an ADM upper on an ADM lower since I already have the ADM lower.

I’ll probably just go with a regular gas block and tube if there isn’t any solid reason to spend the extra cash.

Definitely going to get a legit MK12 clone one day when I finally get a KAC rail or if for some reason they become obtainable easily.

If you already have an ADM lower then yeah, I would absolutely go with that route first. Again, this is from my personal preference POV, but I can't stand how the Radian stuff looks and even $800 seems pretty overpriced for it when all you're getting is ambi bolt release (not hold open like with the ADM). If it pushes all the right buttons for you, then its your money and go for what makes you happy, but those always just seemed to be expensive for the sake of being expensive.

Compare that to a top tier milspec receiver set from Mega/Zev for $200 (or even cheaper for standard priced receiver sets). That leaves your at least $600 in your pocket. Lets say a top tier rail costs between $300-$400, which all blow Radian handguard out of the water when it comes to increased rigidity. The extra money you save over the Radian, even factoring in distributor pricing, basically buys you an Atlas bipod + the Area 419 Arcalock clamp to use with your Arcalock rail.

Also I've pretty much just given up on doing a Mk12 Mod 1 clone lol, if/when I do a Mk12 I'll probably just grab a PRI upper.

 

[Hoody2shoes]

I pretty much use adjustable gas blocks exclusively and have never had an issue. One of my sup arms has around 19k through it. I also service them just like I would any other adjustable part.

If you don't need an adjustable gas block just buy one from a respected manufacturer.

I like my radian lower. It's expensive so ymmv

 

[Thorbeast]

Id skip the 18" barrel and go with 16". I have a mk12 mod 1 clone and it's my least favorite AR. It's not a true clone... I don't have the "correct" gas block. I had a 2.5-10 NXS on it, but I replaced it with a 4-16x42 ATACR. Based on my experience with basically the same rifle you are building... If you aren't cloning, don't bother with an 18" barrel. That's just me, and I know people on this site will disagree, but if I'm going to deal with a 12# AR (with loaded mag and optic), I'd like more capability than 223.

Id much rather use a recce than a spr.

With that said, I agree with some of the comments about the radian builder set. It's not a bad set, but I don't think it's a great deal. If you are going to spend that much money... Just get a kac ras ff rail and a milspec upper.

 

[MontanaMan]

I don't think there's really anything "wrong" with your basic build & it should make a nice rifle.

Assuming it's a rifle gas barrel (since you didn't say unless I missed it) & done by CLE, I highly doubt you're going to either need or want an H2 buffer & a green spring.

But if I were doing it, I'd use a SanTan upper/ lower; it's true ambi & beautifully done & highly functional, & usually a tight or light thermal fit to most barrels. Cross Machine Tool & SLR, also make a great sets. Any of those are my preference over Radian

And I'd use an SLR Ion Lite rail, either 13.7 or 14" & one of their gas blocks; I like adjustable & theirs is the best, IMO, or use an RCA BCG with an adjustable gas key................but with rifle gas & a correctly sized gas port, you will be fine with a non-adjustable GB.....................but, if at some later date you decide to try a reduced BCG/buffer weight system, you'll want & need an AGB too.

As far a flash hiders, go, if that's your preferred muzzle device type, White Sound Defense & Smith make the most effective devices that I know of.

MM

The SLR rail (or a light Midwest or V7) is as good as it get, IMHO.

Geiselle's triggers are hard to beat.

 

[thedude824]

Personally my favorite is the ADM UIC lower for reasons mentioned above, vltor MUR upper, and Geissele MK4 rail. I paid $335, $160, and $240 respectively. An adjustable gas block let's you go from perfect settings for the can to perfect without in a couple clicks. I drop a drop of oil and click 5 clockwise, 10 counterclockwise, then 5 clockwise every 500 rounds or so. No issues on any of my AGBs. Without an adjustable gas block I use an A5H4 with suppressor and switch to H3 without, both with sprinco green. With the H3 and can it was still slamming the BCG more than I wanted. I use Vltor A5 systems on everything other than my Colt which I plan on trying my Bootleg adjustable bolt carrier group with.

 

[xxflyingturtlexx]

I think I have finally figured out my SPR build and I just wanted to ask if there are any parts you would change. Currently waiting on a Scionics NP3 BCG so that I can send it off to CLE to match to a barrel.

Build List

CLE 18" Bartlein MK12 barrel (Unless someone convinces me to go Krieger)
Scionics NP3 BCG
Radian Builders kit (Will a 14 inch rail be to long to run a OCM5?)
Geissele SSAE
Radian Raptor SD
Radian Talon
OCL Flash hider and collar
Vltor A5H2 buffer with Sprinco Green spring
Vltor Buffer Tube
OCM5
ATACR 4-16
Area 419 ARCA rail

Any recommendations for gas tubes and gas blocks?

Anything you would change? Im mainly going with a Radian builders kit because I can buy one straight from a distributor and I know they make quality shit, though I do like the look of the G$ Mk16 rail better. Would it be beneficial to go with some sort of thermal fit upper or would it not make that much of a difference?

Also thoughts on Apache Rifle Works for building it? I would rather pay someone to do it right than have to fuck with it myself, especially considering my fingers have the dexterity of a dead person.

TIA

Radian upper and lowers are heavy for unnecessary reasons and dated. There are lighter and stronger parts nowadays. But if you already had it around; rest of your list looks good.

 

[bfoosh006]

IMHO, your build sounds GTG.
I haven't seen the need for a adj. gb on a .223/5.56 build yet. I tried one ( SLR ) on my 18" RLGS 3gun rifle and it was barely noticeable.
I agree the Radian sets are higher priced, but the features ( ambi ) would offset that in my book. And if you are getting the Radian stuff at a good price, I would go with it.
FWIW, I believe in the benefits of a Thermal or shimmed / Loctited barrel into a upper. Lots of articles showing it helps , even if just a small'ish percentile. I also think a snug upper to lower fit helps wielding of the firearm be more consistent.
Lots of helpful comments / input in this thread.

 

[TonyTheTiger]

I haven't seen the need for a adj. gb on a .223/5.56 build yet. I tried one ( SLR ) on my 18" RLGS 3gun rifle and it was barely noticeable.

With an 18" RLGS and .09" ish GP there's a very good chance that you'll be optimally gassed with standard components. Go all low mass and an AGB may be more useful.

 

[bfoosh006]

With an 18" RLGS and .09" ish GP there's a very good chance that you'll be optimally gassed with standard components. Go all low mass and an AGB may be more useful.

Thank you and Agreed, I did go "Low mass" after the initial Adj. GB only trials, and the difference was more noticable. Different, but noticeable especially with a lighter .223'ish load and decent brake.
When I installed the Adj. GB, I wasn't as knowledgeable about gas port size as I feel I am now.