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Posted: 6/17/2010 3:23:21 AM EDT
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Alrighty,
I have two BCM 16" middy uppers I haven't built up yet. What kind of accuracy have y'all been getting out of them? I'm just wondering if it would be worth making a "RECCE-ish" carbine out of one, or if I should just keep 'em "stock". |
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Quoted:
"regular" chrom lined. Though I have shot 1" five shot groups at 100 yards with mine it won't do it consistently (but my RRA stainless 24" will). It's more like 2.5 MOA on average (and sometimes worse). I asked BCM about this and they claim their stainless uppers are MOA rifles but the chrome lined are definitely not. So far I have tested over 25 different types of ammo/grains with it and I'm pretty disappointed with the accuracy, but this type of upper isn't made to be a tack driver, it's a combat weapon. It functions flawlessly and is my SHTF weapon. Just wanted to give you an idea of what to expect. -Cody |
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Copied my reply from another discussion, thought you might find some of the info useful:
Stainless barrel is stainless steel and is a different material than a chrome moly barrel. Stainless steel 410 is a harder stainless steel than stainless 416. 416 is what most manufacturers make their stainless barrels out of. Cold hammer forging is a process of making a barrel: http://www.rifleshootermag.com/gunsmithing/RSgunsmith1/ Accuracy. A few things to consider when talking about accuracy. Many guys get wrapped around the axel about group size instead on staying focused on "practical accuracy". Often times I see guys getting in heated debates about 1/2" between two different guns and a majority of their shooting will be done at less than 100 yards, with a non-magnified red dot sight, using 55 grain ammo (not match ammo) that they got at Wal-Mart or the local sporting goods store. If you look around the internet, you'll hear a lot of chatter about how much more accurate a stainless barrel is over a chrome lined barrel. Generally a stainless barrel is more accurate than a chrome lined barrel, but not always by a huge margin. One example of many, take a look at the info Molon posted in the link below. Compare the group sizes of the Noveske 16" stainless barrel (0.92" average) to the Noveske 16" N4 barrel (1.24" average): http://www.ar15.com/forums/topic.html?b=3&f=118&t=467919 The difference is just slightly more than 1/3" (one third of an inch). When considering accuracy a few things you may want to ask yourself: Are you going to be shooting ammo (ie. match ammo), with optics (ie. 10x or greater), in conditions (ie. a bench), at distances, etc. that 1/3" is going to matter? Also is your skill set good enough that you can consistantly see 1/3" to 1/2" difference between two barrels on a constant basis? More food for thought when thinking about accuracy: 
03designgroup | Which Carbine Is More Accurate 
Generally a stainless barrel will be more accurate than a Chrome-Moly-Vanadium (CMV) barrel. Not by a huge margin. One example of many, take a look at the info Molon posted in the link below. Compare the group sizes of the Noveske 16" stainless barrel (0.92" average) to the Noveske 16" N4 barrel (1.24" average): http://www.ar15.com/forums/topic.html?b=3&f=118&t=467919 The difference is just slightly more than 1/3" (one third of an inch) Generally a stainless barrel will have a slightly shorter service life. Don't take this comment to the extreme. Because stainless steel is a softer metal it will be effected by heat more than a CMV chrome line barrel. Heat is the main contributing factor to shortening the service life of any barrel. Heat and firing tempo have a greater effect on shortening the life of a stainless barrel. Generally a stainless barrel will usually be a heavier countour and thus will be slightly heavier than a CMV barrel. Weight comparisions: 
03designgroup | AR15 Upper Receiver Weight Comparisons
With this being said, Pat Rogers has 29,000 rounds through a standard BCM 16" mid-length barrel, and it's still going strong (as of June 2010 this gun has over 36,000 rounds on it). Consider that this barrel has been used in a training class enviornment it's entire life. Everytime the gun is rented to a student it's being shot 8+ hours a day and having approximately 1,300 rounds put down range in a 3 day class. None of use have the time or money to abuse a barrel like that. Match and tactical training pics and info using standard chrome lined, cold hammer forged, and stainless barrels can be seen in this article: 
03designgroup | BCM Complete AR15 Upper and Lower Receivers
How accurate does your gun need to be? For most of us, practical accuracy is much more important than group size. I don't have a problem hitting smaller than average targets out to 425 yards with a 3.5x ACOG or Leupold 1.5-5x with my standard chrome lined, cold hammer forged (chrome lined), or stainless barrels using XM193, Winchester Q3131A, Federal American Eagle 55 grain, Black Hills 55 grain, and other 55 grain ammo. When you consider accuracy you need to factor in what type of ammo you will be using. If a gun can get sub-MOA groups with MK262 what does it matter if all you will be shooting is Wolf 55 grain or XM193 or simular ammo. What kind of optic you will be using. If a gun can group sub-MOA groups with MK262 and a 14x optic, can you achieve that same accuracy with XM193 ammo and a 3.5x ACOG? Shooting conditions. Will you be shooting from non-convential positions or from a supported bench? Are you a good enough shooter that you can see a 1/2 or even a 1 MOA difference in accuracy when shooting with XM193 ammo, a 3.5x ACOG, from a hasty barricade at 100 yards? How big is your target? Are you trying to shoot a man sized target at 200 yards or a prarie dog at 400 yards. Accuracy, like many things in life is a compromise. Figure out what you NEED and buy the best equipment suited for your needs. Hope this helps |
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