View Full Version : VLTOR or BCM Upper
I'm starting my first SBR build and recently purchased an 11.5 BCM upper. I also purchased a VLTOR MUR stripped upper. I will be using a KAC URX II rail system for the build. The question I have is would the MUR upper be a better fit/better quality than the BCM? I am asking for because once I get the URX on its not going to come off anytime soon seeing as the tool to unscrew the nut is about $250. :no:
First thing is that you need to understand that they are completely different items. The BCM upper is a standard M4 style upper.
The Vltor MUR is a different animal. It is thicker and has a few differences. The idea behind it was to prevent upper receiver flex, especially when firing full auto.
So the question is do you want a standard M4 style upper or something else.
I'm starting my first SBR build and recently purchased an 11.5 BCM upper. I also purchased a VLTOR MUR stripped upper. I will be using a KAC URX II rail system for the build. The question I have is would the MUR upper be a better fit/better quality than the BCM? I am asking for because once I get the URX on its not going to come off anytime soon seeing as the tool to unscrew the nut is about $250. :no:
First thing is that you need to understand that they are completely different items. The BCM upper is a standard M4 style upper.
The Vltor MUR is a different animal. It is thicker and has a few differences. The idea behind it was to prevent upper receiver flex, especially when firing full auto.
So the question is do you want a standard M4 style upper or something else.
I gotta be honest, I know both items are quality parts but I do not fully understanding the Pro's and con's for both items. I do love the look of the MUR but have no complaints on the look of the M4 style upper. My main concern would be the functionality and fit of the upper with the lower receiver (Noveske).
I just explained briefly the differences. I can't really address pros and cons and you would be fine with either one.
What do you mean by functionality and fit? Of course they will fit. If you mean a little play, then you need not be concerned because it has ZERO impact on the operation or accuracy.
I gotta be honest, I know both items are quality parts but I do not fully understanding the Pro's and con's for both items. I do love the look of the MUR but have no complaints on the look of the M4 style upper. My main concern would be the functionality and fit of the upper with the lower receiver (Noveske).
Iraqgunz built a Vltor MUR supplied upper for me. If I were putting it on a Noveske, I would go all out and get the MUR. The machining and craftsmanship is excellent. It should fit.
I have both, and both are very good.
lethal dose
03-18-11, 23:17
Gunz is correct. They will both fit and a little wobble means nothing... besides, it'd be a gamble at which'd wobble less. Who cares? My suggestion is: buy a barrel and have two uppers. Personally, I think the BCM would best suit my needs as it is more universally designed.
Silver_2325
03-18-11, 23:24
Why are you worried about the cost of a tool if you bought both of those uppers?
I just explained briefly the differences. I can't really address pros and cons and you would be fine with either one.
What do you mean by functionality and fit? Of course they will fit. If you mean a little play, then you need not be concerned because it has ZERO impact on the operation or accuracy.
Yes I was referring to the play the upper and lower might have but also how flush the rail system is to the front of the upper receiver, i.e. a continuous rail system as opposed to a slight gap. Keep in mind this is purely a cosmetic concern and i don't think it will cause problems for optic mounting.
Why are you worried about the cost of a tool if you bought both of those uppers?
I see these uppers as part of a system that could save my life one day and I see the tool as a $250 item I will probably only use once or twice in my life. Just not worth it to me.
Yes I was referring to the play the upper and lower might have but also how flush the rail system is to the front of the upper receiver, i.e. a continuous rail system as opposed to a slight gap. Keep in mind this is purely a cosmetic concern and i don't think it will cause problems for optic mounting.
It wont cause problems for optic mounting because you should never bridge the gap.
Silver_2325
03-18-11, 23:57
I see these uppers as part of a system that could save my life one day and I see the tool as a $250 item I will probably only use once or twice in my life. Just not worth it to me.
Fair enough. What exactly do you do that puts you in harms way, if you dont mind me asking?
The last one I installed on Pappabears fit like a glove and there was no discernible gap that I could see.
Yes I was referring to the play the upper and lower might have but also how flush the rail system is to the front of the upper receiver, i.e. a continuous rail system as opposed to a slight gap. Keep in mind this is purely a cosmetic concern and i don't think it will cause problems for optic mounting.
besides, it'd be a gamble at which'd wobble less.
No, it wouldn't be a gamble at all. The Vltor would be a tighter fit.
lethal dose
03-19-11, 00:27
No, it wouldn't be a gamble at all. The Vltor would be a tighter fit.
I stand corrected. (For the first time ever.)
Fair enough. What exactly do you do that puts you in harms way, if you dont mind me asking?
I am in the USAF but this weapon will not be used when I deploy seeing as most of us cannot use our own weapons. I was referring to a home defense situation or any situation where you must employ the weapon you built to save your life and the life of your loved ones . I have a wife, son and one on the way and hopefully I will never need to use this system in my home but if I do I want to know that I didn't skimp out on quality to save a few bucks.
polymorpheous
03-19-11, 10:49
Personally, I would go with the standard M4 upper from B Co.
No worries that it is a quality part or not.
I built my last build, an AR Pistol, using a BCM M-4 upper, and I had no complaints. The fit/finish was great, and the T-markings and M-4 cuts were perfect. Would not hesitate to buy BCM uppers again. The price difference is a big factor, and the MUR, although VERY nice, is twice the cost. I was more focused on the barrel.
jonconsiglio
03-19-11, 17:41
I stand corrected. (For the first time ever.)
;)
Op, I've owned monolithic systems (LMT MRP) and it made absolutely no difference for my uses. BCM is hard to beat. Vltor has some great stuff but I don't have enough experience with the system to comment on it. I think you're good either way, but I'd rather not be married to a rail.
I have the VLTOR on my noveske and it is a great upper. Looks like a 308 upper,little different look,I'd go BCM upper with a KAC rail.
Why not get a lower and see how things fit? Is the BCM upper assembled? Never tried a BCM, but the MUR fits nice & snug on my LRB lower.
You do realize that each upper is just the start of another AR...
Belmont31R
04-03-11, 22:07
For the gap between the reciever and rail there is no way to figure this out before hand. If you want a zero gap you need to lap and time the rail to the upper. The way the URX works is the rail threads onto the upper, and then the barrel is installed, and then the barrel nut is threaded in. If you look at a URX rail there are TWO sets of threads. To time the rail to the upper requires either luck or machinist fit.
MSTN offers timed upper reciever to rail fittings with zero gap. I have had 3 URX rail systems...the first was put on by Marvin Pitts, a former KAC employee, and the only way to tell the difference between the rail and upper was to hold it at a certain angle under lighting. 2nd was factory SR15 with a cunts hair worth of gap. 3rd is a SR25 EMC with a business card worth of gap.
However I must say the slight gap has zero to do with anything besides a random OCD tick you might have.
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