Comments on: DSA ZM4 A3 AR15 Upper Receiver http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/ Firearms not Politics Fri, 10 Feb 2012 23:24:58 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: shawn http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-25921 shawn Mon, 08 Feb 2010 18:07:59 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-25921 The 53 page thread at arfcom reports that this upper will feed cheep and quality ammo flawlessly with a number of bcg's. The actual owners of this this gun that know how to test it report accurate groups. They no longer offer costume machined ramps because people did not realize the value of such upgrades. Sincerely Shawn The 53 page thread at arfcom reports that this upper will feed cheep and quality ammo flawlessly with a number of bcg’s. The actual owners of this this gun that know how to test it report accurate groups. They no longer offer costume machined ramps because people did not realize the value of such upgrades.
Sincerely Shawn

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]]> By: bp http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-15515 bp Sat, 03 Oct 2009 13:42:19 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-15515 Just a heads-up, M4 ramps aren't a feature any more. Units being shipped recently had hand-filed feed ramps and other QC problems widely talked about on ar15.com. I'm happy with mine despite the feed ramp jobs, DSA chimed in and will not be cutting any more feed ramps on new ones. http://www.ar15.com/forums/topic.html?b=3&f=118&t=458552&page=16 Just a heads-up, M4 ramps aren’t a feature any more. Units being shipped recently had hand-filed feed ramps and other QC problems widely talked about on ar15.com. I’m happy with mine despite the feed ramp jobs, DSA chimed in and will not be cutting any more feed ramps on new ones.

http://www.ar15.com/forums/topic.html?b=3&f=118&t=458552&page=16

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]]> By: jdun1911 http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-15485 jdun1911 Sat, 03 Oct 2009 04:50:39 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-15485 Some of you reading this probably wondering do I have to check headspace on an AR15? No not in an AR15 with a standard BCG. Headspacing is done in the barrel making process. It either work or it don't. It is almost impossible for the AR15 too shoot out of battery. You have a better chance of winning the Mega Million then a KB! due to out of battery issue. I recommend BCM because it comes with an upgraded extractor. It will comes in handy if you decide to use it in upper that has 10.5" barrel or less. http://www.bravocompanyusa.com/BCM-Bolt-Carrier-Group-MPI-Auto-M16-p/bcm%20bolt%20carrier%20group%20auto%20mp.htm Matt, This thread should answer most of your questions. http://www.ar15.com/forums/topic.html?b=7&f=22&t=712401 Some of you reading this probably wondering do I have to check headspace on an AR15?

No not in an AR15 with a standard BCG. Headspacing is done in the barrel making process. It either work or it don’t.

It is almost impossible for the AR15 too shoot out of battery. You have a better chance of winning the Mega Million then a KB! due to out of battery issue.

I recommend BCM because it comes with an upgraded extractor. It will comes in handy if you decide to use it in upper that has 10.5″ barrel or less.

http://www.bravocompanyusa.com/BCM-Bolt-Carrier-Group-MPI-Auto-M16-p/bcm%20bolt%20carrier%20group%20auto%20mp.htm

Matt,

This thread should answer most of your questions.
http://www.ar15.com/forums/topic.html?b=7&f=22&t=712401

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]]> By: Matt Groom http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-15467 Matt Groom Fri, 02 Oct 2009 22:39:39 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-15467 Nitrocarborized barrels? As in Tennifer/ Melonite? I find this VERY intriguing (I tried to convice someone to do this on his guns once!) I am under the impression that Nitriding is the same as Ferritic Nitrocarburizing, but that Carbonitriding is different in as much as it is performed at much higher temperatures. I get confused, so if somebody knows more about surface treatments than I do, please correct me. It should be more durable than hard chrome and more corrosion resistant than Stainless Steel! I might just have to buy one and see how it holds up! I just don't understand the fascination with .22 ARs. Yeah, you have the same (usually heavy) trigger that you do with your go-to gun, but you also have a .22 conversion kit, or upper, or devoted rifle that costs as much or more than dozens of other arguably better .22 rifles on the market. For the price of a devoted AR .22 upper, I'd rather have a decent bolt action .22 and a suppressor. Nitrocarborized barrels? As in Tennifer/ Melonite? I find this VERY intriguing (I tried to convice someone to do this on his guns once!) I am under the impression that Nitriding is the same as Ferritic Nitrocarburizing, but that Carbonitriding is different in as much as it is performed at much higher temperatures. I get confused, so if somebody knows more about surface treatments than I do, please correct me. It should be more durable than hard chrome and more corrosion resistant than Stainless Steel! I might just have to buy one and see how it holds up!

I just don’t understand the fascination with .22 ARs. Yeah, you have the same (usually heavy) trigger that you do with your go-to gun, but you also have a .22 conversion kit, or upper, or devoted rifle that costs as much or more than dozens of other arguably better .22 rifles on the market. For the price of a devoted AR .22 upper, I’d rather have a decent bolt action .22 and a suppressor.

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]]> By: Tony Chow http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-15453 Tony Chow Fri, 02 Oct 2009 19:22:17 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-15453 It's a mediocre basis to build an .22LR upper with decent accuracy. You are handicapped by that .223 chamber and twist rate. It’s a mediocre basis to build an .22LR upper with decent accuracy. You are handicapped by that .223 chamber and twist rate.

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]]> By: Jason http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-15451 Jason Fri, 02 Oct 2009 18:17:28 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-15451 Wow, that is a great deal - thanks for the heads-up! Wow, that is a great deal – thanks for the heads-up!

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]]> By: anon http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-15440 anon Fri, 02 Oct 2009 14:30:32 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-15440 For a _dedicated_ 22lr AR, I'd want a dedicated barrel to avoid using a chamber adapter. Also, for the majority of 22 ammo, you'd probably want a more conventional 1:16" twist. That said; the 1:9" twist would be good if you wanted to build a suppressed rifle to use Aguilas 60Gr sub-sonic rounds. Very Hush Hush. For a _dedicated_ 22lr AR, I’d want a dedicated barrel to avoid using a chamber adapter.

Also, for the majority of 22 ammo, you’d probably want a more conventional 1:16″ twist.

That said; the 1:9″ twist would be good if you wanted to build a suppressed rifle to use Aguilas 60Gr sub-sonic rounds. Very Hush Hush.

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]]> By: Erwos http://www.thefirearmblog.com/blog/2009/10/02/dsa-zm4-a3-ar15-upper-receiver/comment-page-1/#comment-15433 Erwos Fri, 02 Oct 2009 10:21:36 +0000 http://www.thefirearmblog.com/blog/?p=8228#comment-15433 Actually, that could be super-handy for those of us who want to build an AR-15 in .22LR on the cheap. Actually, that could be super-handy for those of us who want to build an AR-15 in .22LR on the cheap.

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