My review of a new BCM 14.5 Middy

AR/M4 AR Technical Discussion
1

Range Report – BCM 14.5” Mid Length

As you will read here, I have a major issue with this new upper. My goal with this post is not to bash BCM (I’m sure they will make this right) but rather to share my experience and perhaps get some insight as to what the problem may be. I intend to contact BCM as soon as I get a “sanity check” here.

The upper is a new 14.5” mid length with a PWS FSC556. It is using a complete new BCM bolt group (ordered separately, not with the upper), an Aimpoint M2L in a BOBRO mount and a Larue BUIS. The hand guards are Cav Arms.

The lower is a Bushmaster which I have owned and used for many years. With my old BM M4gery upper and their pinned-on “Izzy” brake, the BM rifle held under 2 MOA all day, and was capable of 1.25” groups at 100 yards from the bench with a Trijicon Mini ACOG using XM193 ammo. Recent changes to the lower include a Geissele Super Semi-Automatic Trigger, an ambidextrous safety and Grant’s Magpul Industries CTR Carbine Stock MIL-Spec Package.

For reference, here is a photo of the completed rifle in question;

My first shots fired at the range this morning were to get the irons sighted in at 50 yards. Target used was NRA international 50 foot. With the Aimpoint off, I fired my first 3 round group, which was reasonably centered but low and scattered. I made adjustments until the group was generally in the center of the target, but was still scattered.

Knowing that my eyes aren’t what they used to be, I turned on the Aimpoint and made my initial adjustments based on the iron sights. I fired four more 3-shot groups, which were generally centered on the target but still scattered.

OK, maybe I need to bear down and the poor grouping is my fault. I had been shooting off a bench, under cover with the front of the rifle supported on sandbags. I hunkered down, supported the rear of the rifle too and fired some 5-shot groups, using only the Aimpoint. Once again, I was unable to get a grouping.

At this point I wanted to eliminate the possibility that the Aimpoint was loose or the dot was not holding zero. I shot four more 5-shot groups, using both the irons and the Aimpoint. Since I am set up for absolute co-witness, I made a few small tweaks to my iron sights so that the dot sat perfectly on top of the front post. Using the small aperture and keeping an eye on the dot in relation to the irons, I shot more groups. The dot never moved in relation to the irons – the sight picture remained rock solid and the dot did not shift off the top of the front post. This IMO eliminated the possibilty of loose sights.

Luckily, the guy I was with is a NRA high power shooter (goes to Camp Perry every year). He had his 20” NM AR with him and some 77 grain handloads that hold sub-MOA from his rifle. I tried a 5-shot string of those too, but the results were the nearly same and remained completely unacceptable – even for a “service grade” rifle.

Below are the best 50 yard targets of the session using my best bench rest skills and a fully supported rifle. Bottom line, this upper cannot hold 12 MOA with quality ball ammo (XM193) or 10 MOA with handloads using match bullets.

I will be contacting BCM and ask for a replacement – unless someone here can suggest something I’m missing. What could possibly be the cause for this upper to shoot so poorly?

BTW, the rifle functioned flawlessly, and just as smooth as been reported by other users. The SSA trigger is awesome, breaks cleanly. The rifle functioned perfectly and is a joy to shoot…other than the unusable accuracy.

Title edited for clarity.–gotm4

2

I would try and rule out every possible cause before settling on the barrel being the problem.

It looks like the rounds are scattered all over the target. I would make sure the barrel nut was properly torqued. Second, try shooting it without the muzzle break. Since you had the same problems with irons and the Aimpoint and different types of ammo, those should not be the issue.

Also, try shooting some groups in different positions (prone, off-hand, etc.) and see if the rifle still does it.

Just some thoughts.

3

Did you have your buddy shoot your rifle?

4

Jay, I did not but I wish I had.

On the other hand, I’ve been shooting for over 30 years. I used to have bolt guns that shot under 1/2 MOA using the same technique I used today. The rifle was fully supported under the handguards and under the stock, the dot stayed dead-center in the black, the dot stayed rock-solid on top of the front post and each shot was squeezed off perfectly (easy to do with the new trigger).

So, I do not believe it was me nor do I believe there was an issue with the sights. The only reason I can think of for the shots scattering so badly is an issue with the barrel.

So on this subject, what kind of accuracy are others seeing with this upper?

5

With my non hammer forged BCM 14.5 middie with extemded A-2 I was getting 1-1.5 at 50 yards while zeroing with irons and T-1. At 100 the groups were averaging 2-2.5 MOA. All of this was supported off a ruck.

6

make sure everything is tight as mentioned before. How is the crown on that barrel ?

7

My best group with the BCM RECCE 14 rifle was 0.50" at 50 yards with Black Hills Blue Box 77grain HP. Prvi XM193 (which is not the same thing as the Federal I assume you were shooting) produced horrible, and horribly inconsistent, results ranging from 0.95" to 2.35". All were 5-shot groups shot from a bi-pod and a sandbag supporting the rear of the gun with a 9x Leupold optic in Larue mount. 62 grain HP Brown Bear and 44 grain FMJ Wolf both held right at 1.50" on average.

I am not calling you a liar, but 1.25" at 100 yrds with ANY XM913, even Federal, is well beyond the potential I’ve ever seen with that ammo.

Either way, something is clearly wrong with the upper you received, and we all know that Paul will take care of you. I understand your intentions with this thread weren’t malicious and you’re just looking for easy answers that you can fix yourself, but I think you should have given him the chance to make it right (per forum rules too, BTW) before posting.

8

When you installed the PWS FSC556, did you over-tighten? I caused myself numerous problems over-tightenting on an upper last year. Many ways to screw up on this one. You have to install the muzzle device while making sure the barrel cannot rotate with the torque your apply. Using a barrel vise works well. Getting the PWS to line up correctly can be a pain in the arse! Even with shims it took me a while to get one of mine installed correctly.

9

That was my expectation with this upper, and I would have been quite happy with those results.

I used the same support/technique today as when I shot these groups;

Best group ever with XM193 out of 14.5" BM M4gery, 100 yards - typical was about 2 inches;

And not that it is even relevant, but same technique on 100 yard target with Krebs Custom AK103-k, Aimpoint using Brown bear;

Since I decided on a 50 yard zero for this rifle, I started at that distance. I never made it to the 100 yard line.

This is a complete upper with a pinned brake so I have no way of knowing how tight it was torqued or the condition of the crown. However, the brake is perfectly timed with the barrel and the overall workmanship on the upper is absolutely top-notch. Thus, my suspicion of a bad barrel…

Again, this is not meant to offend BCM or break any forum rules - I’m simply in search of answers that I may have over looked.

10

Loose barrel nut or you just got a lemon are 2 most probable answers as long as you installed everything correctly which is hard not to do (sights).

Id just make sure the barrel nut is tight (Ive had one come loose on me before, and had groups that big before I realized what was going on…loosened up while I was shooting it), and check the bore to make sure everything looks normal. Its possible the grooves were messed up in the manufacturing process.

Oh and check the muzzle crown if you can. See if it got nicked or that its still looking good. Crowns can cause lots of accuracy problems because its the last thing the bullet touches before it leaves the barrel.

If everything checks out on your end then send it in and you’ll get a new upper. While its “proper” form to contact the mfr first sometimes there are issues that can be fixed at home without having to send stuff all over the country just to get an answer, and wasting peoples time they could be out shooting.

11

The issue is puzzling. Absent a muggled muzzle crown or an over-torqued barrel nut, I’m clueless. I’d contact Paul at BCM. I’m sure he’ll work with you. This performance is decidedly uncharacteristic of his products.

12

Thanks to all for your input.

Crown looks good - I can see no nicks or damage.

Removed the handguards and though I do not have a barrel nut wrench, it appears to be tight (have no idea on torque). Grabbing the upper receiver and barrel, there is no apparent movement or loosness between the two (if that means anything).

I will wait to hear from Paul - I’m sure he’ll ask for it to be returned which I will gladly do. I’m sure it will be taken care of and I will keep this this thread updated.

13

Update

BCM has already responded to my email (on a Sunday!) and have provided the information to ship the upper back. It will go out tomorrow.

14

Here is a thought: the barrel threads’ concentricity to the bore.

I have a 14.5" gov’t middy (Sabre) that has a permed A2X flash hider. When attempting to use a laser bore sighter before going to the range, to get the irons close, I noticed that I was unable to get any consistency at all, unlike other uppers I have used this bore sighter on, with shorter muzzle devices. It is a bore sighter with the cone shaped end, that indexes the sighter in the bore.

Well, scratching my head, and taking a closer look, it was obvious that the muzzle threads, or possibly the flash hider’s threads, were not concentric to the bore. The sighter would bend and bind a bit to the side, when seating it inside the muzzle. But, this condition didn’t really affect accuracy (that I can tell), with the A2X flash hider, but I suppose that it definitely would, when attaching a long brake, like the PWS FSC556. I would bet this may have something to do with your problem. This is another reason I didn’t want to risk a permanent brake on a factory upper, that I couldn’t verify thread concentricity.

15

I think the problem is caused from you posting pictures of the rifle prior to shooting it. Now it thinks that it is pretty and feels like it shouldn’t have to work hard. You can either get it fixed, or simply yell at it and slap it a few times to put it in its place, followed by ignoring it for a couple of days.

Just kidding. Nice rifle, I’m sure it will get fixed soon. I want a similar upper. Show us the groups when you get it back please.

16

then you probably need to spend more time with it. i can pretty consistently pull 1.25" with federal xm193 with several different barrels.

17

Did you check the optic and mount?

18

I was wondering about the optic and mount myself. I had a duty gun earlier this year that was grouping terribly. It wasn’t until I had a fellow officer shoot it, that we noticed I had put the Larue mount on half assed. Once it was tightened down, it ran fine.

19

i did that once, a billion years ago… not even sure what kind of mount it was. must have been a QRP… i don’t think any of the current mount manufacturers existed yet, then… but my groups went from crap to crazy pretty quick- first group was like 5" at 50, opened to like 10", to finally closer to like 4 feet- i had holes in other people’s boards. i wiggled my barrel, we checked the cartidges for damage, inspected the muzzle/MD for damage/obstructions… finally, my spotter poked his finger at my RDS, which visibly moved under the pressure. d’oh! we were embarrassed.

first thing to check.

20

Same guns, same range sessions, <1" best groups with Black Hills 75 and/or 77.