My New Year’s resolution was to thoroughly clean all my guns. Typically, I wipe down BCGs and punch bores after a range session, but it had been a while since I had done a good detailed cleaning. I bought one of the Teslong bore scopes from Amazon to get a feel for barrel condition and effectiveness of my cleaning materials and methods.

These are all my barrels and my personal experience with them. YMMV. The sample population is all chrome lined barrels from BCM, Colt, Criterion, Daniel Defense and FN. Most barrels are 5.56mm AR platform, but I’ve also included an FN 300BLK and SPR. For the purpose of this thread I’ll categorized them as follows:

“Good” is a known shooter that consistently groups under 4-MOA; well within “Rifleman” standard with iron sights and cheap ammo.

“Bad” is a barrel that has been disappointing. It may group within USGI standards (5.6” spread 10-rd group @100yd) but takes match ammo, good optic and a lead sled to get there.

“Ugly”… I’ll let the photos speak for themselves; otherwise same criteria for “Bad”
Barrels are listed by perceived level of precision by my own experience. Bear in mind this is not scientific by any stretch of the imagination. These guns have sighting including iron sights, red dots and scoped. Ammo used ranges Wolf Gold to Federal GMM  and Black Hills Mk262.

Data presented by Make and profile, Caliber/Chamber, Barrel/gas length, rifling method and twist, round count.

Photos are generally posted from throat to crown. I tried to highlight characteristic features for each barrel...

18 JAN UPDATE:

Got to the range this evening; had to shoot at 25yds indoors so targets are scaled accordingly (grid is ¼” squares).
Turns out the ugly BCM will shoot to acceptable military specifications, and not horribly bad with decent ammo.

Optic used was a Nikon Prostaff 3-9x40 Adjustable Objective

Barrel: BCM BFH ELW 14.5" Mid-Gas w/ Sure Fire WARCOMP

Target data information is average for the groups on each target.

Individual group data is adjacent to group.

Federal M193
Max Spread (CTC): 0.7786” 2.975MOA
Mean Radius: 0.2896” 1.107MOA


Black Hills 77GR TMK
Max Spread (CTC): 0.8765” 3.348 MOA
Mean Radius: 0.2999” 1.146MOA


BCM ADI 55gr SBK
Max Spread (CTC): 0.5484” 2.095MOA
Mean Radius: 0.1917” 0.732MOA


WOLF GOLD 55gr FMJ
Max Spread (CTC): 1.0916” 4.170MOA
Mean Radius: 0.3848” 1.470MOA


5/2 UPDDATE:
Follow-up with 100yd groups from ugly BCM. Optic used was SWFA SS 10x42. Group size (dispersion in MOA) are consistent with the 25yd results with ADI 55gr holding around 2-MOA and BH 77gr holding around 3-MOA. Assessment of the BCM barrel stands: it's pretty average shooting despite the bore looking like it was drilled with a chisel. I would say that most of my service weapons have grouped about this well, on average. (edited for clarity)

ADI 55gr SBK (10 rounds)



Black Hills 77gr TMK (10 rounds)

The “Good”…

FN SPR, .308WIN, 24”, CHF 1/10”, 140 documented rounds.





Criterion Hybrid, .223 Wylde, 16” mid-length, button broached 1/8”, ~200rds






Daniel Defense Gov’t, 5.56mm NATO, 14.5” mid-length, CHF 1/7”, ~200rds




Colt SOCOM, 5.56mm NATO, 14.5” carbine, button broached 1/7”, ~1500rds






Colt Gov’t, 5.56mm NATO, 16” carbine, button broached 1/7”, unknown (low) round count






FN medium profile, .300 AAC BLK, 10.5” pistol, CHF 1/8”, ~200rds

The “Bad”…

FN (Collector Series) SOCOM, 5.56mm NATO, 14.7” Carbine, (supposedly) button broached 1/7”, ~500rds





Note the significant chatter marks in the bore. This gun was disappointing out of the box; FSP was bottomed in its adjustment range at 25m zero. New contract upper fixed the elevation range, and the gun has started shooting a little better with use. Still on the poor end of expected performance.

Colt Gov’t, 5.56mm NATO, 14.5” carbine, button broached 1/7”, unknown (higher) round count







Bought this barrel used, specifically for an early M4 clone. Throat erosion looks decent; but significant muzzle erosion and damage to chrome plating (poor cleaning methods?).

The "Ugly”...

BCM BFH ELW, 5.56mm, 14.5” carbine, 1 in 7” CHF, unknown (low) round count







Holy Hell was I surprised when I saw inside this barrel! This is my wife’s gun, so it is rarely shot beyond 25yd/m. Zeroing at 100m achieved around 5” 5-shot groups, so I guess that meets BCMs military specification. I have, generally liked BCM’s stuff, but damn! Perhaps this explains why my previous BFH barrel shot like poop… I though it was just the pencil profile.

ETA: Yes, the leade is cut crooked; it's not an illusion.

BCM barrels don't do much for me (granted, n=1 in my instance).

What borescope are you using? I outta buy one.

Great post!  I love techy stuff.  I should bring my borescope from work.  I'd like to see how my DD(CHF/CL) has held up over the last few months and look at my old Bushmaster and see how that thing has fared over the last two decades(CL'd for sure, no idea if they were ever CHF)That BCM looks terrible.  Maybe you could get them to replace it.

Pics aren’t the best quality; for home use, it’s perfectly adequate.

BCM is gaining a reputation for bad barrels.  Thanks for doing this.

Those photos are pretty damn good quality.  Leaps and bounds better than my 2 year old Snap-on bore scope with the built in 4 inch screen.  I just added it to my shopping cart in Amazon. The ability to use the PC is a huge bonus.  Thanks OP.

Fantastic thread.....almost reminded me of reading an old Molon thread.

In regards to the BCM barrel.....just another drop in the bucket full of terrible accuracy reports.

At this point after years of hearing about 5-7MOA BCM barrels, and now seeing more and more evidence under the scope, no way I'd ever buy one.

Thanks for the post, really enjoyed reading it.

Shame BCM doesn't dump bad batches of barrels in the trash for youtube instead of gas tubes. So much for all that QC, even with BCGs. Maybe they should cut back on the ad/paid actor revenue and redirect those funds to QC roots.

Good to see Daniel Defense and Criterion holding up to their reputations.

I always figured BCM just bought cheap/shittier/seconds barrel blanks from FN. Which is fine, except they should price them less than $300 lol

Me either lol

Nice thread

Yeah I will be sticking with my Daniel barrels as well

I always liked BCM and have one that still shoots great. I wonder how much of it is just built up crud? Did you try some JB Borepaste with the patch on a worn out brass brush?

I haven't really looked into it with a borescope yet and planning to buy one this year thanks to this thread.

Also, excellent topic. I was just looking up about borescopes as I was coming into this forum and saw your thread. I think I will go ahead and order one off Amazon.

Getting a borescope...

Everyone's Rational Mind:


Everyone's OCD:

I use KG2 bore polish before zeroing. It Had the same tool marks, but was nice and shiny. Pics show the bore after 40 rounds and a cleanup.

Thanks for taking the time to put this together. It's interesting to compare different barrels visually from the inside.

It really is wild how within the last few months, I've seen an explosion of end user bore scope pics.

This is a great advancement for us end users, and will allow a whole new level of scrutiny to a mfg's barrel quality.

I know these things have been around for years, and years, but apparently they are getting cheap enough for the masses to use.

Or barrel nuts, taper pins and muzzle devices installed with monkey torque? All of which are known to wreck accuracy (precision) and all of which BCM has been well known to do. I wonder how many of these BCM bad accuracy reports are from BCM assembled uppers v.s. BCM barrels bought seperately and installed by an individual who didnt blow a gasket while torqing fasteners/muzzle devices and/or using a sledge hammer to force taper pins to wedge against the barrel and in turn deform the bore? To be fair BCM claims milspec quality and will always refer back to it. In other words if it technically meets defined milspec standards for grouping or otherwise, they will defend their product because it is explicitly advertised as such. We have seen this before with rough yet still in spec BCM components (bcg comes to mind).

Criterion advises against taper pinning and frowns upon even conical tipped set screws to install fsb/gb because even when installing with care they were able to record measurable bore deformation with both attachment methods via air gauge.

Speaking of Criterion..it is no suprise to see how nice the bore of their CL barrels are, considering they are lapped and being (or at least originating) as an offshoot of Krieger.

Thanks all for the feedback.

I think it is important to emphasize that my pictures should only viewed as anecdotal evidence. I don’t believe this small sample paints a comprehensive picture for any of the represented  manufacturers.

In fact, every one of these barrels has, technically, met their advertised level of performance. I can confidently say the FN SPR and Criterion are truly “MOA” or better. Some barrels like the 1500rd Colt SOCOM have exceeded my expectations, and the FN Collector M4A1 was a let-down.

I am however starting to see a trend with BCM, and hope they take note of this thread. It’s going to be interesting as more people start posting up pics!

My BCM SOCOM barreled upper is 6-7 years old & one of the better shooting ARs I’ve ever owned.

I'm not one to talk smack about BCM, but I also have one of their barrels (bought new, used, uninstalled) sitting an a rifle cabinet as a spare that did not live up to my expectations.   You don't need a borescope to see the tooling marks in its bore.

Oddly, it shot 55gr ball noticeably better - good, even - than heavier match rounds.  I'm going to build it into a spare carbine upper with a dot or irons at some point.

I have another barrel from a different maker, QPQ'ed, that looks awful inside and even has a faint ring that looks to be a tooling mark.   It shoots anything I put it in great.

Wow! Great thread and a real eye opener!

New, New Years Resolutions:

1. Get borescope
2. Clean rifles

OMG some of those gas ports look atrocious...I'm assuming they're are drilled prior to the chrome lining process? Also, technically wouldn't it be better to have these drilled centered within a groove vs. a land? Or, worse straddling both as in some of these pictures? My OCD is kicking in big time

Does BCM make the barrels in-house?

BCM (IMHO) is the most overrated brand out there. If it weren’t for their symbiotic relationship with TOS, I doubt they’d have half the notoriety they currently possess. I would love to see their marketing budget though.

Anyone have any bore scope pics of Ballistic Advantage barrels? Especially the Hanson barrels. Would love to know how they compare to some of these.

As for BCM, I like some of their stuff (upper receiver, lower receiver, PNT trigger, that's about it) but wouldn't own any of their barrels or BCGs just due to personal experiences. I am also not a huge fan of their receiver extensions. It seems like adjustable stocks love to stick to those things for some reason.

thanks for the reminder to do some cleaning!

great thread!

double post.

BCM makes good stuff but barrels aren't impressive at all. I did find that a 16' bfh mid shot cheap 55gr ball 223 very well though but any quality or even milspec ammo wasn't very impressive. Don't want to bash BCM as I bought into the hype and was a fanboy but after even the cheaper PSA uppers that out shot my BCM I think I'm never paying premium for another BCM upper again. I still like the other stuff though.

That looks very similar to my DD Lightweight 16" midlength barrel.  I'm not sure on total round count.  Might be as much as 600 rounds.

Throat and leade.
Attached File


3 inches past the throat.
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8 inches past the throat.  
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Gas port.
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Debris field after the gas port.
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I haven't done any real accuracy work with this one yet but my previous DD lightweight barrel could get under 1 MOA with handloaded single fed SMK 80 grain bullets.

According to the SOGLW guy here, BCM makes pretty much nothing in house.

wow, great post. Thanks.

Excellent technical thread, thanks for taking the time to do this write-up and all the detailed pics!

I have an old BCM barrel I bought back in 2007, a lightweight 14.5" that's pinned and welded, and you can see machining marks on the shoulder easily. It shoots ~6 MOA with ammo that's widely accepted as an "accurate" loading, that also shoots well in my other barrels. Low round count, reliable, just not very accurate. I need to get a bore scope and see how bad it really is. When I first started shooting it I thought I just had a bad range trip, it was blasphemy to speak ill of BCM back then.

Great technical report; it’s nice for someone to put out something of substance and not opinion. I have three BCM barrels, a 14.5” SOCOM profile barrel for one of my SBR’s, a 16” C-8 HB clone, and 20” barrel. Never had any problems with them, but then again, maybe I have not shot them enough. I have plenty of their equipment, and although I really think they make quality stuff, I do find the a lot of their gear over priced and just a huge billboard for advertising.

There are many good barrel makers out there; I practically own most of the high end barrel brands. But my go-to and favorite barrel will be the Colt 14.5 SOCOM barrel, followed by LMT’s 14.5” Carbine barrel. The Colt SOCOM is just accurate, and for the money, you cannot beat it. You can buy a complete barrel assembly with FSB and barrel nut for around $300 USD (depending on the flavor of the month, maybe cheaper) and every one I own is just dependable and accurate. The LMT comes in Close second, and I find myself shooting it more often

Absolutely, and that's why I brought up Molon's name in my earlier reply.   He was the king of informative tech posts imho.

This is an awesome comparison, great to see this data.

Wondering about getting a bore scope camera and checking out a few barrels.

That sounds accurate based on what I’ve seen/heard over the years. IIRC they get their BCGs from CMT.

If you dig into the ATF production reports over the years, it’s not actually surprising that BCM doesn’t roll their own hardware. Their annual numbers are pretty abysmal. So it doesn’t seem viable for them to invest in their own production lines.

Great post, thanks for pulling this together.

Grab one of those Teslong Borescopes off of Amazon, at worst you're out 50 bucks.

Centered whithin a groove tends to be preffered, half in a land and half in a groove would likely be the most disruptive and least desireable. It is absolutely possible to ensure that the gas port will be centered in a groove but is highly unlikely in a  mass produced barrel and really luck of the draw. Krieger is one manufacturer who is willing and able to locate the gas port within a groove without fail, Im sure others like Bartlein, Lilja and various high end barrel finishers are capable as well. No matter how you cut it, gas ports are disruptive and non conducive to precision.

Also keep in mind, many factors other than round count are at work here such as pressure, velocity, barrel length, barrel mass/contour and volume/rate of fire. Unless all factors are controlled and equal any borescoping done after firing is inconclusive. You can destroy a barrel (any barrel from any manufacturer) in short order with extreme pressures and abusive firing schedules.

As far as accuracy (precision) and consistency potential? On a CL barrel uniformity and consistency of the plating is one of if not the most critical factors and cannot be gauged with the naked eye or borescope.

I think I’ll be picking one up. Was going to try the endosnake (sp?). There was a pretty favorable thread about it maybe a year ago. I held off because I think it  only had a straight on view (no angled attachment). The Teslong solves that miss and looks like it has a much better image quality.

Just trying to decide if the newest version is worth the extra $20 ($49 vs $69). The only difference appears to be the new version is completely rigid.

@forteefiveseventee

8.3" .300 Blackout BA Hanson Pistol Length AR 15 Barrel w/ Lo Pro, Performance Series:

Fixed link to product page

Edit: for clarification this is a QPQ/nitrided barrel.

BA does not advertise is this is CHF or button broached. The tool marks are less pronounced than the FN Collector Series barrel. Note the length of the lands in the throat to leade transition. The #1 and #5 lands are significantly lunger than the rest. Lands are numbered in clockwise sequence from 1 to 5. TDC  is 12 o’clock.
I have not yet shot this barrel; I’m interested to see how it shoots.

BA Performance Series Hanson Profile, .300 AAC BLK, 8.3” pistol, 1/7” 5R, Zero rds.

BA did offer a limited run of CHF/CL Hanson profile barrels. They were explicitly advertised as such and were priced around $300.

Looks like someone was shooting 16 rounds per minute...

I have a 12.5” BA that I bought over Black Friday. Still waiting on some other parts. So, if I pick up a bore scope in the interim, I’ll snag some pics.

WHAT?! I have long lurked here but I thought the whole point was BCM made EVERYTHING in house?  I don’t feel like I’ve drank the koolaid so to speak but what in the actual fuck?