Interesting results after grouping my standard and BFH BCM barrels - update 02 JUN

[Wake27]

Chrome lined barrels don't really break in much, and not to the extent I would expect a measurable difference in group size.

The Razor is a quality scope, but ANYTHING can break, so it's worth looking into. Not my first guess though.

How good are you at keeping a repeatable eye position relative to the scope? And do you find the Razor's crosshairs too thick for the type of targets you're using?

I agree on the first two, the scope was the last thing I thought would be the problem this whole time. I like the reticle quite a bit and haven’t felt like I’ve had any issues with it.

The eye box and cheek weld topic is kind of difficult. I don’t remember if I addressed it in my OP or not, but that was the first guest that the instructors and two of the better shooters had at the LPVO class where I was having issues, mainly because of the 1.93 mount. But then the instructor shot it and had the same POI shift which somewhat killed that theory. I do not have a tactile reference point for my face so there is a possibility that in between groups, my cheek weld is not exactly the same. However, I’m almost always aware of any time I break it during a group, and for five round groups like these where I’m in the prone on a mat, with rear bag and bipod, I make sure that it doesn’t happen often.

That’s also part of the reason I’ve been doing these at 50 instead of 100. It’s enough distance to notice that there is a problem, but the target on 6x is still fairly visible and I figured a shorter distance would only help minimize the impact of any shooter error or environmental considerations.


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[SomeOtherGuy]

mainly because of the 1.93 mount. *** However, I’m almost always aware of any time I break it during a group, and for five round groups like these where I’m in the prone on a mat, with rear bag and bipod, I make sure that it doesn’t happen often.

That’s also part of the reason I’ve been doing these at 50 instead of 100. It’s enough distance to notice that there is a problem, but the target on 6x is still fairly visible and I figured a shorter distance would only help minimize the impact of any shooter error or environmental considerations.

Quick hits:

1.93 mount is high, not something people would usually choose for precision. Unless your face is HUGE (do you wear a size 8.5 hat?) it may be causing you enough trouble to open up groups within the small amounts we're talking here.

Scope parallax is a concern for the small issues you're looking at here. A 6x scope doesn't have much parallax, but it is fixed at 100 (typically) and being at 50 will significantly increase its effect, even if the target focus is perfect. Again this wouldn't add 12 MOA to a group, but when you're concerned about 2 MOA groups vs. 1-1.5, it doesn't help.

Find someone with a known-good scope that has higher magnification and a 1.4-1.55" height mount and shoot some groups with that. If it has adjustable parallax use any convenient distance, if not use its fixed parallax distance (typically 100 yards but not so on all scopes).

[turnburglar]

This thread has gotten kinda long to reread the whole thing; but based on my own experiences: I immediately thought you had a scope issue looking at the targets. This can only be tested by switching to a known good optic, or taking the optic in question and doing a box test, or to 'confirm' zero with one load, but multiple times.

However there is.... another ... theory. Hear me out.


You have a BCM that wont shoot, you have sent back Noveske's and you had a KAC upper fail to work? Sounds like someone put a curse on you. Maybe try H&K? Otherwise get out of AR's completely before this all culminates into something terrible. I couldnt imagine my luck being that bad with some many top brands.

^#sarcasm

[Wake27]

This thread has gotten kinda long to reread the whole thing; but based on my own experiences: I immediately thought you had a scope issue looking at the targets. This can only be tested by switching to a known good optic, or taking the optic in question and doing a box test, or to 'confirm' zero with one load, but multiple times.

However there is.... another ... theory. Hear me out.


You have a BCM that wont shoot, you have sent back Noveske's and you had a KAC upper fail to work? Sounds like someone put a curse on you. Maybe try H&K? Otherwise get out of AR's completely before this all culminates into something terrible. I couldnt imagine my luck being that bad with some many top brands.

^#sarcasm

Yeah dude, don’t even get started. To be fair, BCM never said that the barrel was bad and if the scope turns out being the problem, it puts a lot of those groups in question. And KAC was eager to get the upper back, but it’s been there for over two weeks now and I haven’t heard a thing so there is a chance that when they test it, they don’t have any issues (that seems less likely to me though).


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[Kyohte]

My wife has a term for this, “gun drama”. Some people, myself included, are magnets for it.

Higher end gun manufacturers have more issues than some may think, or maybe I am cursed, too. I have had some form of trouble with HK, FN, Colt, BCM, and DD just to name a few. I’ve come to (only half-jokingly) believe that many gun manufacturers know that their product will never be fired more than 7 times (data from an old Colt study) and make their products accordingly.

What has separated the good from the bad for me is how the problem is rectified. I know if I send a product back to BCM it will come back fixed or replaced. If I send a product back to a super popular “just-as-good-as”, it will come back broken with a dishonest note saying they test fired it and it worked fine (true story).

[opngrnd]

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I like the green/brown rifle on the left. Quite a bit, actually. My next FSB build will look like that.

[Wake27]

My wife has a term for this, “gun drama”. Some people, myself included, are magnets for it.

Higher end gun manufacturers have more issues than some may think, or maybe I am cursed, too. I have had some form of trouble with HK, FN, Colt, BCM, and DD just to name a few. I’ve come to (only half-jokingly) believe that many gun manufacturers know that their product will never be fired more than 7 times (data from an old Colt study) and make their products accordingly.

What has separated the good from the bad for me is how the problem is rectified. I know if I send a product back to BCM it will come back fixed or replaced. If I send a product back to a super popular “just-as-good-as”, it will come back broken with a dishonest note saying they test fired it and it worked fine (true story).

That reminds me that I need to update my customer service thread since both BCM and KAC were great.

I like the green/brown rifle on the left. Quite a bit, actually. My next FSB build will look like that.

That's the beater rifle. It is actually one of my favorites because of how well it works for a $200 upper (before upgrades). Its right under 1k rounds with both brass and steel and has yet to give me an issue. Its also the only one I really felt comfortable painting. I like how it came out for the most part, but it helped affirm the notion that I really don't have the patience to do it well. Some day I want to send a gucci AR to get a gucci cerakote job, but that's pretty low on the list.

Back on topicish, my Razor has been at Vortex since Friday and I don't have another magnified optic so I'm trying to figure out what to do for Sunday. It'll be my last range day for a few weeks and I want to keep grouping. Plus I have a shiny new KAC 14.5 to try out.

[Wake27]

Got the Razor back today with a note stating that Vortex found a "loose/split reticle." That gives more credibility to my suspicion that the original BCM barrel was really just a consistent 2MOA barrel and the weird shifts were in fact due to the optic and despite trying it on other uppers, I didn't test it enough to eliminate that barrel from suspicion. I feel kind of bad that they replaced it, but I appreciate that they did. Unfortunately my range access will be even more limited for a few weeks, hopefully I can get an hour at the indoor range to try it out but that'll probably be it.

[jpmuscle]

Got the Razor back today with a note stating that Vortex found a "loose/split reticle." That gives more credibility to my suspicion that the original BCM barrel was really just a consistent 2MOA barrel and the weird shifts were in fact due to the optic and despite trying it on other uppers, I didn't test it enough to eliminate that barrel from suspicion. I feel kind of bad that they replaced it, but I appreciate that they did. Unfortunately my range access will be even more limited for a few weeks, hopefully I can get an hour at the indoor range to try it out but that'll probably be it.

Where have you been shooting outdoors?


I’m in NoVa


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[SomeOtherGuy]

Very interesting, and explains a lot.

I would email BCM to let them know. I don't think they will expect anything from you, and it might help them monitor quality and stop asking themselves if there is some hidden defect in your original barrel.