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Mk12 Mod0 suppressed (BCM vs. PRI) Special Forces rifle + MK262 ammo + AEM5 – accuracy review

today we discuss a global war on terror
era classic that has garnered a cult following unlike any other… the Mk12 Mod0 special purpose rifle we pit an original factory PRI rifle upper for an
accuracy challenged against the BCM reproduction we also test our equipment
with some of the most popular 75 to 77 grain ammunition to include the
venerable military issued Black Hills Mk 262 mod1, IMI razor core, MagTech
and Hornady Black finally we test the OPS Inc, or Allen engineering suppressor
for its effects on the weapons platform’s accuracy so charge your glasses, and
strap in for this nine hole review on the Mk12 Mod0 In the early 2000s
while Soldiers and Marines were still advancing through Iraqi streets with
iron sights M16s, SOCOM had started developing a concept for a lightweight,
modular, accurate, and nimble designated marksman system for the next
generation’s issue… the mark 12 system was built around the black hills Mk262 77grain 5.56 nato cartridge… the 77 grain projectile had a higher ballistic
coefficient and out-performed other 5.56 cartridges in terminal ballistics and
flight characteristics the mark 12 SPR was initially designated as a
special purpose receiver, and to be only issued with the upper receiver, however,
with a surplus of M16A1 lower receivers and butt stocks in inventory, CRANE began
to issue the Mk12 Mod0 as a complete rifle with A1 lower halves, the Mk12 Mod0 was most
recognizable for its PRI carbon fiber free floated handguard. The Mk12 Mod0
is far more rare in general service and closely associated with a US Army’s 5th
Special Forces Group, but the rifle is rare for a reason… early adaptations for
the rifle had interface issues between ARMS and PRI parts.
PRI currently manufactures a MK12 Mod0 complete rifle or upper receiver… that is widely
popular within military rifle reproduction enthusiasts. In 2012 BCM
also released their copy of the Mk12 Mod0 system without the ARMS rail on top. The
BCM is deemed less desirable than the PRI variants to collectors and uses a
1:8 twist stainless barrel Today we have a PRI mark 12 upper
receiver on an A1 type lower that resembles an issued Mk12 Mod0 more
closely with a swan sleeve, shooting against a BCM Mk12 Mod0 upper on a
Colt M4 marked lower. The BCM lacks a swan sleeve to decrease unnecessary
weight, and uses a LaRue LT158 mount that adds 10 MOA elevation for long-range shooting
both rifles one identical Vortex 2.5-10x32mm Vortex 2.5-10x32mm scopes to
duplicate the functions of the issued Night Force scope for those who complain
that we aren’t using issued optics… we get it. We have Night Force and US Optics
scopes on other rifles and appreciate quality optics. That said, the Vortex seen
here is not the limiting factor for this setup to reach 800 yards. Both rifles
also have match grade triggers installed all targets were shot at 100 yards the
rifles were alternated between the nine-round groups for barrel cool-down
intervals and the environmental between the shot groups were entirely the same so how did we do? With the IMI colorbox
the BCM won by a four percent smaller nine shot group at 1.7in
the IMI brown box was the worst-performing ammunition and the PRI
won out by a 15% smaller nine-shot group at 2.3in. MagTech yielded the best group of the day with the BCM printing a 1.3in
nine-shot group that was a 48% smaller than the PRI’s group the Mk262 was a
little disappointing with the PRI barely winning out with a 1% smaller
nine-shot group at 2.2in in the past we’ve seen the Black Hills 77grain
TMK target loads to compare much closer to the 1.2 MOA nine-shot group range finally Hornady Black 75 grains was a win for the BCM with a nine-shot group
that was 6% smaller at 1.98 inches, the BCM
narrowly wins out at a 4% smaller average group size when compared to the PRI now we notice that our group sizes
seemed a little bit higher than what some people of the internet reported… to
dispel any doubts and to learn about the effects of the suppressor we took the
BCM back to the range and tested for a point of impact shift with, or without
the suppressor… it was a different day and I well rested now and shot from a shaded
position. one of the first things anyone would notice while shooting the AEM 5
is how quiet it is the ops Inc suppressor was a major
design adaptation to the Mk12 system the break and collar on the Mk12
is one of the most distinctive features that separates a rifle from the rest.
Years after Ops Inc went out of business Ron Allen from Allen engineering
continued the manufacturing of the AEM5 suppressor this suppressor is known for
its zero point of impact shift meaning the rifle will impact on the
same location whether suppressed or unsuppressed the results… were staggering. Indeed there
was no point of impact shift the black hills Mk262 group size was 37%
smaller when suppressed at 1.7 inches the magtec’s group sizes were actually
almost exactly the same at 1.3 inches the IMI brown box was just
as horrid as a first test, but the suppressor did manage to decrease a
nine-hole group size by 51% and ended up at 1.9 inches the IMI color box had a 37% group size reduction from the suppressor yielding
the tightest nine-hole group of all of the tests at 1.28 inches, which
most of the rounds actually fall into a 0.9 inch group Hornady black also
benefited from a 22% group size reduction where the suppressor attached yielding a 1.62 inch group when comparing the
results between the two days there was less than a 4% variance
between the unsuppressed BCM uppers group sizes suggesting that both the
shooter and the equipment were consistently performing when we took the
BCM Mk12 Mod0 to the practical accuracy range, we were even able to hit
800 yard head size targets in strong winds despite the projectiles lacking energy the 77 grain 5.56 bullet still retains
about the same energy as a light .38special would have at a point-blank range we also observed that the bullet drop
out to 600 yards away was very comparable to a 175 grain 7.62×51
projectile, although the wind drift was significantly more… one problem however
is that BCM cut the barrel dimensions incorrectly since the original step for
the BCM suppressor collar was cut too shallow the suppressor was not locking
in tight in recommended 6-8 turns, but
rather 4 turns. I had to work with Allen engineering directly to get a
custom barrel collar made for the suppressor to time correctly. The PRI
uses the original Douglas Barrel and has no issues now that was a lot of data… let’s
try to break it down for a few conclusion points ONE, the BCM
handedly beat the PRI in the accuracy Department when fed with MagTech. The
tightest group that the PRI was able to obtain was 1.76 nine-inch group with IMI
colorbox… 35% larger than the BCM’s unsuppressed
with MagTech’s at 1.316in TWO, the AEM five suppressor gave
us a 30% decrease in average group sizes with no point of impact shift. an
interesting observation was how the suppressor changed the casing ejection
pattern and that the PRI gas Buster charging handle on a rifle worked
flawlessly to vent excess gases away from the shooter when suppressed In fact, rounds from the magazine turn from this… into this. That’s from all that back pressure. unsuppressed… these are suppressed See the difference? THREE. Magtec’s
77 grain ammunition was the most consistently delivering accurate
ammunition with an average between all tests at 1.47 inches, it
yielded an 11% to 65% decrease in average group sizes when compared to any
of the other a munitions tested while the IMI colorbox yielded the
tightest group in while suppressed we cannot easily recommend it
the IMI color box gave us a 50% tighter group size than the brown box ammunition as there
is too much variance between different lots at the end, the Knights Armament
Mk12 Mod1 ultimately became the issued rifle as KAC did not have
fitment issues the Mk12 Mod1 even turned into a general issue rifle for
Marines to some collectors, the BCM would never even be a choice of purchase
because it does not use all of the original PRI parts for us we are
perfectly happy with the sound of a struck steel plate at long distances
under the puff of an efficiently suppressed rifle… we’d love to hear your
thoughts about our test feel free to send us pictures of your Mk12 for us
to re-post on our Facebook page. We also encourage you to send us your nine-hole
groups shot at 100 yards as a comparison between our variants and yours thanks again for tuning in and we’ll see you on the range!

100 thoughts on “Mk12 Mod0 suppressed (BCM vs. PRI) Special Forces rifle + MK262 ammo + AEM5 – accuracy review

  1. We again emphasize that we run 9-shot groups, so the size is larger than 5-shot groups.

    We do this so that we can have a better idea on where the rifle places shots under the stress of (reasonably) sustained fire.

    This matters the most when we are shooting multiple targets at long distances.

  2. Most of the guys complaining about your large group size only shoot 3 shot groups. I have a clone using the Aero SPR 1/8 twist rifle, and it shoots 1.2" 10 shot groups ALL DAY with Black Hills 77gr and 1.75" with Federal Black box XM193. I'm very happy with it. Especially since I uave $950 in the entire rifle. And its easy to shoot to 700 yards.

  3. My impression is hand loads provide significantly tighter groups than boxed ammo. Wouldn't it be prudent to determine the absolute accuracy norm with loads and selected bullet manufactures then determine a delta from boxed ammo? You mentioned a Douglas barrel? Why not utilize the very top barrels, I.e. Krieger? Special Ops operators test various barrels?

  4. 𝕃𝕖π•₯𝕀 π•₯π•™π•’π•Ÿπ•œ π•₯𝕙𝕖𝕀𝕖 π•˜π•¦π•ͺ𝕀 𝕗𝕠𝕣 π•₯π•’π•œπ•šπ•Ÿπ•˜ π•₯𝕙𝕖 π•₯π•šπ•žπ•– π•₯𝕠 𝕀𝕙𝕠𝕠π•₯ π•’π•Ÿπ•• π•–π••π•šπ•₯ 𝕒 π•§π•šπ••π•–π•  π•π•šπ•œπ•– π•₯π•™π•šπ•€…π”Έπ•Žπ”Όπ•Šπ•†π•„π”Ό π•”π• π•Ÿπ•₯π•–π•Ÿπ•₯!

  5. Quality video. I’d be curious to put my SPR with hand loads up against these and see how she fairs. I don’t have a 9 shot group as that seems an odd number (no pun) to use. Most precision shooters won’t pay attention to anything less than 5 shots but will not typically take the time to shoot 10 shot groups. With that said my SPR has shot as tight as a .24 moa 5 shot group at 100 yards with hand loads and has popped many milk jugs at 1000 yards with 77 gr Berger’s and 23.5 gr of Tac. Check it out. 18" AR-15 SPR vs Milk Jug at 1000 Yards

  6. I am looking for about your product please leave me a message when I post this I am looking for more information on this much run find one much run

  7. I find all of this interesting as hell. But as an Australian, have basically no idea what all the different types of bullet are, the acronyms, measurements (grains?..).. Americans just seem to take that knowledge for granted haha

  8. What if you are a girl and you strap on instead of in
    (I know its not THAT funny but I thought it seemed funny)

  9. So what's the deal with tighter groups when suppressed? Is it just that hanging a weight on the end improves the barrel harmonics?

  10. Great review. Huge bump for Magtech. I had no idea that Magtech was a serious contender when it comes to match grade ammunition.
    About 8 years ago, I have built a clone of a Mk 12 mod 1 upper with Noveske ss barrel. It still does 3/4 MOA even after 1400 rounds. I am not sure that Noveske even offers barrels in that profile. Good stuff, love your reviews.

  11. I’ve shot a lot of mk262 mod1 out of my work MK12 with way better results, that being said each lot is different for sure

  12. I cant believe the zero shift thats for the no loss in accuracy but instead improved, thats amazing imo.
    Awesome review. Thanks

  13. I have to question technique here. His grip changed like three times between different shots on this video. I feel as though shooting from a bipod with a rear bag would be more accurate then balancing it on a backpack. Just some questions I have about his consistency.

  14. Just a thought on the group strings,bipod load.From the looks of it the vertical dispersion could be attributed to shooting off a pack without consistently being able to load the same into the stock.I know alot of the guys use and shoot off packs religiously but when youre looking for repeatedly grouping a round bipod load shows almost 100% of the time in a vertical string of holes.

  15. Ok so i shoot long range bolt but dont own anything fancy when it comes to AR's… so heres my question.. how is it that a sub $1000 savage AR shot at my home range can hold better groups that a mil-spec specially designated marksman build? I may be very ignorant of some factors here not being an AR guy but id be interested in knowing if anyone else thinks those groups seemed a little large…

  16. I just bought a mk12 upper and the aem5 suppressor is on the way do you know if bcm fixed the dimensions on their barrels I would hate to have my suppressor not fit

  17. Awesome video! So glad a I subbed, I’m currently finishing a MK12 Mod H build and cannot wait to get it all together!

  18. Kind of surprised the groups weren't better in the initial testing…pretty poor showing don't you think?

  19. Head shot at 800 yards? I think your groups would shrink if you had used Black Hills 77gr OTM or TMK. I consistently get under 1MOA with these ammo out of my 900$ RRA AR15.

  20. Marksmanship skill would have easily produced groupings in the half MOA arena with any match grade ammunition, for 20 round record strings. After all, it's about the match conditioned rifle/ammunition capabiliy not the effect of stress on results. Grouping size and shape suggest shooter error from inconsistent position and sight alignment. Marksmanship skill could have yielded sub MOA even from the backup irons. Creds: CMP-USAMU MRI coaching SDM/TTT/SAFS, US Distinguished Rifleman, American High Power Rifleman (Long Range)

  21. You should be using CEP (Circular Error Probability at 50%) or Mean Radius, not Group Size. For the example, the U.S. Military's M24/M110 standard is 0.6 MOA CEP. In my testing I also use 10-shot (pretty close to 9-shots) and I get similar group sizes with 77gr ammo (Black Hills 223, Black Hills 5.56, PMC SMK) of 1.6" to 2.7". But the CEP's are 0.54 MOA to 1.1 MOA. CEP is unaffected by number of shots. The more shots you make, the more accurate the CEP measurement.

  22. For 77gr ammo my go to is the Fiocchi 223. Shoots sub moa in everything I put it in. 3/4-1/2 moa out of a couple rifles. Its kinda pricey though.

  23. Do you have any other suggestions on how to get the suppressor to time correctly on the BCM? I would love to run that suppressor and the mk.12 muzzle break to a similarly similarly performing rifle, although less authentic.

    This is an amazingly in-depth video. You can tell alot of passion went into this. I've watched this video about 30 times.

  24. I bought a Eagle Arms "Golden Eagle" DCM gun back in the day that would shoot 69/77 Sierra's MOA all day long out to 600 yds. Even with my Stoney Point gauge using Sierra 80's the bullet would fall out of the neck the throat was so shot out, the gun would still shoot. I went to Camp Perry one year and was going to have the AMU truck 'float' the barrel when they said they couldn't and it wouldn't be worth doing it. The secret was the stainless steel truck axle that Eagle Arms used.
    I am not impressed with those groups.

  25. Wow I was on the edge of my seat expecting better accuracy from what I've heard of of the mark 12… Wow that was anti-climactic and sucked… The guys did their job in prove that though … hats off to 9-hole

  26. 2 months after you posted this, i bought one after debating on the two rifles. Iv'e put 600 rounds of the magtech through my BCM, been reposted on IG via Hogsaddle on 03/11 day (marine scout sniper day) smashing steel consistently and quickly at 450 yards. 7 months in on my AEM5, still waiting…… I'm going to live in the hills where i shoot when it comes.

  27. I picked up the Centurion MK12 MOD 1 built my Monty Leclair.
    Last time I shot my MK12 with 77G OTM. I shot 1.6" at 100 and 1.9" at 200. A Co worker who is a retired USMC DM shot a 1.2" at 100 and 1.8" at 300 . I have mine on a Colt Lower with CMC 3.5 Pound 2 Stage Trigger . I use Vortex 1-8Γ—

  28. with an average of 2" / 100 yd group is nothing to write home to mom about…maybe if chambered in 6.5 Grendel there would be better groupings…

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