SPR Build Part II | Barrel Length | Data Collection | Flatline Fiber Co.

[@ilikecars212]

There needs to be more data driven content on guntube. Thanks for this!

[@flatlinefiberco]

This is only the start. Thanks man!

[@Maine307]

i have asembled my SPR this year,556 - with a LaRue- uperlower and 20 inch barrel.. and have been slowly building my distance up. i reload too, soo it been a fun journey. especil being retired USMC 0369.. and being able to take my time and really pushing the limit.. i am building a 12 inch w/ can to compliment pair it off.. i am glad to see other taking it serious and using common sense as well.. great video and glad to see such a huge amount of common sense and reality. set up looks great!!

[@flatlinefiberco]

That’s awesome man. Long range shooting has definitely been a longer journey than anticipated. I by no means have arrived. Im still just a beginner but I enjoy sharing my journey and some things Ive learned.

[@DefZen343]

when people ask about the effectiveness of 556 at 800 meters, i usually say most people cant make hits at those distances as it is, let alone make effective return shots after being stabbed by an ice pick 😅 alot of people have died to ice picks and 22Lr bullets. id also say its more effective than not hitting them at all 😅

[@flatlinefiberco]

Absolutely! I guarantee the person on the other end won't hand around to see. That's kind of the point too. Plus the further you push the guns. It makes those 200-600m shots easy.

[@p51mustang24]

That's very true, and, btw, it's also why I'd recommend people strongly think about whether they really need an 18" barreled SPR vs a 14.5 or 16. The magic of the SPR is the ability to deliver rapid follow up shots at medium-long range in a light weight package. It's not an ultra-long range range platform, even if you can maybe get out to 800+, it excels in the 100-600 range.

[@DefZen343]

@@p51mustang24 i prefer an 18 inch gun since they cycle so smoothly with the rifle length gas system, makes follow up shots super easy. also the length keeps most rounds super sonic out to 800. i shoot 2gun out to 200y and dmr matches out to 750 or so pretty often so i want my gun to shoot well in both settings. Most people probably wont shoot those distances often enough to justify the unnecessary weight and length of an 18inch, ive seen people shoot very well with 14.5s out to distance too.

[@Edc-Guy]

@@DefZen343what barrel do you prefer. “Someone I know” is in the process of the 18” build.

[@DefZen343]

@@Edc-Guy ive had good luck with Faxon's 223 wylde match barrels, i have 2 of them that shoot very well with most factory ammo. White oak armament and Sons of liberty gunworks 223wylde match barrels also works well for my friends at matches too. lots of good options out there

[@scott2228]

I’ve got an 18” OPS12 SS barrel from Ballistic Advantage on my SPR. I run the OC OCM5 suppressor. Gun/barrel is amazing. Looking forward to taking an Intro to Precision Shooting class next month. I’m going to look into that 16” Centurion barrel for one of my rifles. Sounds perfect.

[@flatlinefiberco]

That's awesome! It is such a valuable thing to learn. Train hard man!

[@JBsX39]

My SPR/ GPR is a Ballistic advantage 16” barrel. Expo arms rail. On an aero upper lower and lpk. With a PA slx nova in a larue spr 104 mount. With a piggyback 507c in a Trijicon mount. Currently have only taken it out to 100 yards. But I’m gonna be setting up a 500 yard range on my family farm. Hopefully it goes well. Also rocking a modlite okw with arisaka mount/body and surefire ds00

[@flatlinefiberco]

Sounds like a good build!

[@cajuncarry]

Awesome video man. My SPR is currently rocking an 18in but I have been debating going down to 16 or 14.5. This video helps a ton.

[@flatlinefiberco]

Just depends on your personal preference and goals. Thank you!

[@joquin4618]

Yeah, I got the criterion lightweight 18” barrel on my mock12 and it’s a tack driver! I’ve noticed it gets good velocity out of most ammo compared to my other rifles

[@bayadger6970]

Same with my 13.9"... tried 8 brands and 6 grouped sub moa compared to my Proof CF which only likes 3

[@mikem4011]

Excellent video. With the drop of the new Garmin Xero Chrono making getting MVs more convenient for the average shooter, going to be good to see all the collective data starting to be published to compare traditionally held beliefs and assumptions with actual real-world metrics to prove/disprove various theories. Longer is not always faster and ammo selection and barrel profile matters more than barrel length.

[@flatlinefiberco]

Thanks man! I couldn't agree more. I picked up the new Garmin a few weeks ago and it's really nice. It's very easy to setup and use. Im looking forward to putting out more content using it.

[@SonotCali]

Great video! Love the gun and the website on your tee. I wish I knew someone in my area with knowledge like you or a class in my area to help you build dope and just teach you basics of longer range shooting.

[@flatlinefiberco]

Thanks man! I'm purely a student as well. Just trying to share the things I have learned along the way. What area are you in?

[@SonotCali]

Northeast Texas Southwest Arkansas city named Texarkana.

[@Redneck_Oper8tor]

Excellent video man. Love hearing the thought process behind the rifle.

[@flatlinefiberco]

I appreciate that!

[@jayellgee]

Thanks for sharing your data. I’m currently waiting on one of these 13.9 CORE drops in the next month, but for a different reason than chasing that extra velocity. The numbers were very encouraging, though.

[@flatlinefiberco]

No problem man. I was shocked. I will be shooting it alot more to see how it holds up over time. Thanks!

[@charlesruiz6492]

Thanks for all the data, most people talk about ballistics with longer barrels but you explained that very well. Thank you for sharing brother! Awesome video

[@flatlinefiberco]

Thank you!

[@robertgatewood514]

Hodge barrels are just fast. I also starter my journey on a 12.5 with a 2-10. Velocity on it was nuts and rifle was more than capable at the Bruiser class.

[@flatlinefiberco]

Yea man. I believe the tapered neck of the barrel helps speed up the bullet I believe. Dont quote me on that though. I was also told by a SME that all cold hammer forged barrels have a taper. So there may be something else going on with the Hodge soec FN barrels. I definitely want to try one in 12.5. mine runs great, but Im curious how much more performance I can push out of it. Thanks for the comment man!

[@SCQT]

I cant speak directly on Hodge as ive never gotten my hands on one, but i can say ive experienced the same effect on my 12.5 Triarc. Dont quote me exactly on the numbers, but i believe i was seeing ~30fps bump over my previous 12.5 criterion (i BELIEVE it was chromed). Now the Triarc is a MLGS and the Crit was a CLGS, so add that into the voodoo math if desired. Both shooting the same 77SMK over XBR load. Doesnt sound like much but ill take a free 1.5in of velocity any day Tried my 12.5 in SPR config, and loved everything about it other than the balance was pretty much directly over the TD pin. Its more a personal issue though as i like to run LAW folders(so heavy...) and 18x MK5. I think 14.5 might be enough to balance that setup where i want it, but decided to put the 18" Compass Lake Bartlein back on because it is simply the most absurdly accurate and consistent AR barrel ive owned. Will be my last 18" though once its shot out.

[@Runningmancs]

Using the new garmin chrono my 14.5” suppressed criterion core barrel was pushing imi 77gr bullets at around ~2700 average 10 shot groups. Some of the imi hit near 2800 from a different lot. I did also experience a few popped primers maybe one every other mag. This makes me think ammo and the criterion wylde chambering may be playing a part.

[@flatlinefiberco]

It's definitely the barrel that is helping you get those velocities. Great to hear others are having the same experience. Popped primers would just be an ammo problem I assume, but not sure. I have the Garmin on order and can't wait to try it out! Thanks man!

[@Runningmancs]

@@flatlinefiberco after speaking with some other nerds at the range they had seen similar issues and knew what barrel I had before I even mentioned it because they had also seen the same popped primers issue from other criterion 223 wylde chambered barrels.

[@DutchK75]

@@Runningmancs IMI stuff is pretty hot as well. It's not uncommon for IMI to pop primers.

[@joquin4618]

Interesting 🤨, my 18” criterion lightweight barrel aero precision build was had some popped primers with the 77gr AAC ammo from palmetto state armory 🤷🏻‍♂️ I thought it was the ammo, but now that you mention it, it may be the barrel 🤔

[@flatlinefiberco]

@@Runningmancs That is interesting. I have not experienced that at all. I primarily shoot pmc xtac and IMI 77 smk. I will try some black hills, which has even more pressure and report back.

[@hannibalbarca2939]

Those are some crazy velocity results. I am most surprised by the criterion being so fast.

[@hopewilliams6705]

Quality!

[@flatlinefiberco]

Me too man! We gathered data on that barrel this spring. I referenced back to it after the barrel swap. I couldn't believe it, so I had to get it on a upper again. Then got back on the Chrono and sure as crap it was still hitting those number. I believe the barrel twist and manufacturing process comes into play. I will go back and shoot some groups with it soon to see how it does now that I'm a better group shooter. I love it.

[@GhostofTerra]

20" masterrace for the win Good vid, man. I'm glad you talked about other factors for bullet speed - barrel length is definitely only one part of the equation. The harder the twist, the less velocity that round is going to have,

[@flatlinefiberco]

Thanks man

[@GhostofTerra]

@@flatlinefiberco ye

[@kaceyweaver8073]

I recently got into shooting precision gas gun stuff and I love it great video… also I snagged a Flatline Choco chip padded sling for my SPR!

[@flatlinefiberco]

Awesome man! It really is a never ending journey and I love that part about it. Thanks for the support man!

[@kaceyweaver8073]

@@flatlinefiberco absolutely... I live in Northeast Georgia, so when I found out you guys were based in my home state I gave your slings a try. I got my first FFC sling about 3-4 years ago, and now they’re my go-to. I have 3-4 of your slings now. I love them

[@jason91notch]

Great video. I’ve seen examples like this a few times as well. That to say, all things being equal, (which they never are), a longer barrel will shoot faster. Physics are physics. I’d love to see a comparison where all things are truly as equal as possible. Someone needs to get 4-5 of the exact same upper, only difference between them being barrel lengths and test it that way. Same barrel manufacturer, barrel model, ammo, on the same day, same chrono, etc.

[@flatlinefiberco]

Yea for sure man. The point I was making is that not all barrels are created equal. Kind of discrediting the general statement of well to shoot at X distance you NEED a 16", 18", or 20" barrel. If you can shoot tight groups and your getting the velocity numbers it doesn't matter. Then there is use case as well or maybe all someone has is a 12.5" or 14.5". They can still go out and practice long range shooting. Really encouraging people to get out, train, collect data on their rifles, and not be discouraged because they don't have the perfect rifle for the job. Thanks for the feedback man!

[@jason91notch]

@@flatlinefiberco absolutely! I think some people chase velocity for velocity sake, which isn’t the right thing too. I’ll take 1/2” MOA in a 12.5” gun with low velocity over 1.5” MOA out of a 18” gun with good velocity. Like you said- the most important thing is training. Learning your weapon. Try lots of different loads and figuring out what it likes best. The best gear on earth can’t beat time behind the trigger. Cheers 🍻

[@mtnbound2764]

good video with great points! im working up a 16" spr now

[@flatlinefiberco]

Good stuff! Thanks man!

[@tstrongarm77]

A later iteration of the Mk12, the Mod "H" (Holland), was actually a 16" gun. That's impressive distance man

[@flatlinefiberco]

Yup! Thanks man!

[@TheMikeshannon]

Apples to apples a 16" should be a higher velocity, however a cleaner smoother bore and with the hodge a tapered bore, you can potentially see a higher velocity. Ive seen this on a bunch of different comparisons with various hodge barrel lengths

[@flatlinefiberco]

Absolutely man. Material, lining, crown, twist rate, ammunition, upper assembly, and maybe even a muzzle device can play a part.

[@tsafa]

How are you making your wind adjustments at 1000 yd? Do you have a spotter I'm telling you the adjustment or are you self spotting on a mil grid. Do you have any trouble spotting the impacts? What magnification are you working in? How far were you able to push the PMC x-tac. What was the typical group?

[@flatlinefiberco]

Depending on conditions I may be able to spot my own impacts but I’ll typically have a spotter. They will give me the adjustment based on wind conditions and impacts if I can’t see them myself. I will hold for wind because it changes quickly. Spotting is definitely a skill I have worked on a lot myself as well. I use a Mark 4 spotter with a TMR reticle. I have the same TMR mil reticle in my 2-10. I like it alot it allows me to observe the area around the target and isn’t cluttered with a big grid. Spotting my own impacts at 1,000 can be tough at times. If the conditions are right, Im shooting against a big dirt berm, and there is fresh paint on the steel it’s possible. I typically will shoot around 6-8x magnification at that distance. I have pushed Xtac out to 1,000, but I haven’t measured the groups. I have found it to do pretty great out to 900. If I want better performance at that distance or past I will shoot 77gr sierra match king. They group really well out of the 16” MK12 barrel. I will be shooting paper out at that distance sometime soon. When I do I will measure the groups for sure. Thanks for the questions.

[@dustyrhodes1655]

Did you go with the TMR or PR1 on the Leupy? About to get a 3.6-18 for my 16" gasser SPR and in the reticle choice conundrum. I have Xmas tree reticles on my bolts and leaning towards the Tremor 3 but also have a itch for a simpler one.

[@flatlinefiberco]

I went with the TMR, because I prefer simple reticles. They don't clutter my view from seeing the environment around the target. I have been taught to dial for my elevation and hold for wind. I find it to be very easy to do this with the Mark 5 with TMR. I also have the TMR in my spotting scope.

[@Averkie_Skila]

:57 so true. There’s so much conflicting information out there, you have to find out for yourself what really works. Chasing opinions of other people can get expensive

[@flatlinefiberco]

Absolutely man. Go shoot what you have, train, and collect the data. If it doesn’t meet YOUR requirements then find what does. That’s where people may get stuck. Trying to buy or build what does meet their requirements.

[@alexandersolomon8294]

Nice video brother! Solid review

[@flatlinefiberco]

Appreciate it!

[@Wammywammsters2024]

This was a great video! Quick question, if you used a 14.5” or a 16” Criterion barrel, do you think the velocity would have been faster than the Criterion 13.9”? I know you showed us different barrel lengths but they were different barbells. I would like to think that a longer Criterion barrel would continue to increase velocity but maybe I’m wrong. Would love to know your thoughts! Thanks!

[@flatlinefiberco]

Yes it should. I have not tested another Criterion barrel to see for myself though.

[@veracitysolutionsllc]

Good vid!!! Can’t wait for the marksmanship gurus to show up like last time.

[@flatlinefiberco]

Thanks brother! I'm looking forward to it myself! We gotta get in on some of these videos🙌

[@fr3d_fly351]

Not doubting, but you realize that consistent center of mass 'hits' at 1100m on a 18"-wide target (large silhouette) is between 1 to 3/4 moa right? Is the SD on IMI that good?

[@flatlinefiberco]

The SD on the IMI isn't great to be honest. Without look at my book I believe it was around 18. The SD on the 55gr XTAC has been far better even over different lot numbers.

[@flatlinefiberco]

Also at that distance Im more worried about wind than anything. I know what myself, gun, and bullet is capable of. If my math is good and I have a good spotter. Then it's very doable. At that distance with 556 Im not trying to get a 1 moa group man.

[@yanniclariviere]

“ Black Hills 77 gr TMK Muzzle Velocity: 14.5 inch barrel: 2589.4 FPS avg. (Daniel Defense and BCM lightweight hammer forged chrome lined, carbine & mid-length gas system) 16 inch barrel: 2683.1 FPS avg. (BCM C8 SFW heavy profile chrome lined barrel w/ Simon steel sleeve, carbine-length gas system) 18 inch barrel: 2687.5 FPS avg. (Rainier Arms Select Medcon stainless polygonal rifling, mid-length gas system) 18 inch barrel: 2712.5 FPS avg. (BCM Mk12 SPR heavy profile stainless steel, rifle-length gas system):” Hmmmm

[@flatlinefiberco]

Good data man!

[@yanniclariviere]

You too bro! Wildly varying results, it really DOES come down to so many different factors that we are only scraping the surface with length, twist, treatments, design etc. its got me pulling my hair out trying to find out what exactly the secret sauce is. It’s clear it’s no one part of the system but all parts working together in the most efficient and effective method to achieve the best results. And yet….all we have now is more mystery lmao

[@flatlinefiberco]

Absolutely man. So many variables to consider vs just barrel length. Ill take that 16” bcm barrel you have all day long over the others. Especially if it groups well. Have you tried other 77grn ammo as well? My MK12 barrel shoots the black hills a good but faster than IMI.

[@nahbrahhh]

Which Block 2 class are you talking about ?

[@flatlinefiberco]

Praecore & Counting Coup Tactical - Distance Carbine Block 2

[@nahbrahhh]

@@flatlinefiberco Do you think it’s worth taking their Distance Carbine Block 1 with RDS + magnifier for someone who has experience shooting to 300 with this combo ?

[@dancarter7009]

Is that a chrome lined or nitrided Criterion barrel? Thank you sir.

[@flatlinefiberco]

Chrome lined

[@dancarter7009]

Thank you brother 🤙🏻

[@flatlinefiberco]

@dancarter7009 My pleasure dude!

[@projectblackhills]

Awesome build 🤙🏼

[@flatlinefiberco]

Thank you!

[@tabariousberry3753]

I use criterion core 16 1:8 mid length in a radian. I just bought a 16 1:8 in rifle length I’m gonna test it.

[@flatlinefiberco]

Great barrel!

[@SonotCali]

Have you ever fired aac 77 grain ammo. My 18 inch spr shoots it very well. Just curious.

[@flatlinefiberco]

Not yet, but I have some. Plan to soon though!

[@BillyBOB-sm3rl]

I have a 14.5 colt 1:6 right hand on a rifle. With a surefire flash suppressor. EOTECH sight. It shoots good.

[@flatlinefiberco]

That's awesome man. Good stuff!

[@bonvaicu]

im about to get my first rifle, which one would you recommend Daniel Defense V7 16 inch barrel or Daniel Defense V7 SLW 14.5 barrel ? / California Compliant

[@flatlinefiberco]

Is the 16" Cali compliant?

[@bonvaicu]

@@flatlinefiberco 16" is CA compliant,, we don't have much choices here ?

[@flatlinefiberco]

@@bonvaicu Sorry Im not brushed up on Cali complaint stuff. Do they both have the goofy pistol grip or is it just the 14.5"?

[@bonvaicu]

@@flatlinefiberco fix magazine , I'm leaning on getting the 14.5"

[@JacksonMalcolm]

No free lunches, velocity without barrel length means pressure. Check your brass.

[@flatlinefiberco]

Brass looks good buddy. I will continue testing though. It did have a bit more ass behind it then before, but it also had a milspec lower on it. We will see if it starts acting funny when it gets an A5 buffer and H2- H3 to slow that bcg down. We will see in time. 🙌

[@narutobroken]

No info on the scope, the mount or why you chose them?

[@flatlinefiberco]

Check out the previous video where I do an overview of the rifle. kzbin.info/www/bejne/hHOzh6mIrb6jbNksi=eMO5kStf96loC2DW

[@scott2228]

I need to find a way to rent or borrow a chronograph.

[@flatlinefiberco]

Check out Tac swap or other forums. There should be alot of people selling their old chronographs at half price to get the new Garmin.

[@scott2228]

Thanks. I’ll 100% take a look.

[@MochiMoose]

He was getting more velocity because he was giving it that Hawk Tuah between each shot. Nothing to do with the barrel. Just some good ole spit lube

[@flatlinefiberco]

💦💦

[@goldy4631]

Drink every time he says "um"

[@flatlinefiberco]

You’re welcome

[@SCQT]

Love what you're putting out man, keep it comin Kinda boring though as i cant find anything to argue with.... Personally i think far more people should be looking to start their long range journey with 556. If you can get consistent at distance with an AR shooting decent 55gr, then moving to 77s, once you switch to a bolt gun shooting high BC 6mm etc, it feels like cheating. Feeling like you're cheating is where you wanna be

[@flatlinefiberco]

Absolutely man! Thank you for the support

[@mrshort2379]

An accurate barrel to me, is one that will shoot off the shelf 55/62gn ammo at 100m, with a 1-1.5 moa or better without having to use match ammo. If a manufacturer is listing, it has a sub Moa accuracy at 100m with match ammo, to me its not worth purchasing! To each their own when it comes to barrels or anything else for that matter. I want mine to shoot what ammo is commonly available..

[@flatlinefiberco]

I can get along with that. Except for me its not any off the shelf ammo, because its easier to avoid problems. PMC Xtac is my go to readily available ammo. It doesn't cost much more than cheap ammo and it's the most reliable consistent SD ammo Ive shot.

[@jrcumming997r6]

A barrel that groups 55gr at 1.5moa would be an absolute unicorn. You have unrealistic expectations

[@flatlinefiberco]

Sub MOA sure is nice though! That centurion can do it with 55gr Xtac as well as 77 smk IMI

[@jrcumming997r6]

@@flatlinefiberco I wish my 16” Centurion Recce would. It hates everything but Black Hills lol

[@veracitysolutionsllc]

@mrshort2379 could you share what 55/62gr you're getting off the shelf that shoots 1-1.5 moa? Also, what barrel?

[@Two_Names]

Great topic and great information shared. I can't wait to chrono my 16" and 13.7" HM monobloc barrel uppers when I get them. Mo data = mo betta. To those with some questions about the long-range effectiveness of the dinky little .224 bullets, I invite you to visit the Rokslide forum and look for the topic titled ".223 for bear, deer, elk and moose." You read that correctly. It's a monster of a thread but it demonstrates the importance of bullet design and hit placement first and foremost, followed by velocity (and that only a function of getting the bullet to the target and at a certain speed to allow the bullet to upset as designed). Given that a fella there showed results of a 77gr TMK at just north of 1400fps, aka 800ish yards, on an elk...

[@flatlinefiberco]

That's awesome man! I haven't shot anything that large with 556, but Ive taken two deer with my 12.5. like you said with a good round and good shot placement it can be done. I used Lehigh Defense controlled chaos.

[@CaLiKiDRyaN]

Inserts for the PIMP when?

[@flatlinefiberco]

Next week

[@CaLiKiDRyaN]

@@flatlinefiberco thanks love your nylon stuff

[@flatlinefiberco]

Thank you man!

[@BlackDiamondgunsandgear]

Woooooooo

[@flatlinefiberco]

Yeah boiiiii!

[@Gaining_Elevation]

Take a shot of liquor every time he says “umm”. 😅

[@flatlinefiberco]

You’re Welcome!!! Lol

[@koengCO]

👍🔥🔥👍

[@flatlinefiberco]

🤘🤘

[@Steve-ke7rz]

What is up with everyone and 16" spr..mine us 18 and I feel real spr should be and is 18"

[@Steve-ke7rz]

I feel like yours ,being 16 with a 2 stage is just an ar with an lpvo on it idk

[@flatlinefiberco]

So what about the MK12 MOD H?

[@jimjones9239]

12.5 in barrel at 700 yards hit will have the Taliban trip and fall, then get up and run away. Close quarter short barrels have lower round speeds that drop off quick for long distances.

[@flatlinefiberco]

@@jimjones9239 Is that so? Man, I guess my time was wasted then.

[@Thedannyboy765]

uhm

[@KevinWood44]

Cute fairy tale story. "Consistent" center mass at 1200+ yards, with a 11" I bet 1 or 2 people even believed this

[@mikeevans3221]

Ummmmmmmm

[@flatlinefiberco]

Perfect comment from a Bama fan 🤣

[@veracitysolutionsllc]

@@flatlinefibercoRoll Tide!

[@flatlinefiberco]

@@veracitysolutionsllc We sure gone see one hell of a game come Dec 2nd!!! Go Dawgs!!!