Weirdest AR upper ever - XDTalk Forums

Ishpeck · 12-11-2008, 01:16 PM

Murdoc Online AR Five Seven: 5.7×28mm AR Upper

What do you do with your mag well if you've got one of these installed?

nateroach · 12-11-2008, 01:19 PM

Quote:

Originally Posted by Ishpeck

Murdoc Online AR Five Seven: 5.7×28mm AR Upper

What do you do with your mag well if you've got one of these installed?

if this is like the other 5.7mm uppers that I have seen, it ejects the spent brass through the mag well.

nateroach

StewieGriffin · 12-11-2008, 01:22 PM

My friend ordered one of these. It's suppose to be delivered today. Only reason why he got the AR is because of this. He has a FN PS90, so he wanted to keep the same caliber. I'll have to ask him about where it ejects when I see him and the set up tomorrow.

Yuppicide · 12-11-2008, 01:24 PM

nice!!!!!!

**RoninSteel** · 12-11-2008, 01:40 PM

Seems like an awkward combination there. Access to the magazine could be quite difficult with optics attached. Also, think about firing inside a building with concrete floors in a combat situation. The spent brass being dropped at your feet could be troublesome.

Wild Rice · 12-11-2008, 01:41 PM

Both the PS90 (which I own) and the AR57 (which I don't own) feed from a longitudinal topside 50rd magazine that feeds the rounds via a 90 degree spiral tunnel into the chamber. The action is straight blowback and the AR buffer spring system is used. The casings eject straight down, via the mag well in the case of the AR57. This makes both the PS90 and AR57 completely ambidextrous. The downside is that the casings end up under your feet. They sell a fabric pouch brass catcher for the PS90 and it would be easy to make a similar one for the AR57. Some people have removed the top, follower, and spring from an AR mag to make a metal brass catcher for the AR57, but there is a chance a casing could bounce up into the action. The 5.7x28 is a neat, flat-shooting little round and the PS90's bullpup design is very compact and fun to shoot. The PS90 is fascinating to disassemble due to its ingenious design. The AR57 shown in the link would be restricted due to the short barrel. You would want a 16" AR57 upper. One advantage of the AR57 would be to practice shooting your AR system at an indoor range that does not allow rifle calibers. You could also build an AR57 with a nice match trigger. The bullpup design of the PS90 requires a long trigger bar that makes the trigger somewhat heavy and spongy.

StewieGriffin · 12-11-2008, 01:45 PM

I emailed my friend about the upper he is about to get, and he sent me this picture... scroll down to the very bottom!

sourpatch45 · 12-11-2008, 01:56 PM

i would love to have one of those for a SBR, but for a full size rifle it kinda defeats the purpose of the 5.7 round which was for smaller weapons, why use a less powerful 223 if the rifle is full sized?

but i would love to get a shortened version to use on my SBR lower.

lutheranpriest · 12-11-2008, 02:31 PM

Quote:

Originally Posted by sourpatch45

i would love to have one of those for a SBR, but for a full size rifle it kinda defeats the purpose of the 5.7 round which was for smaller weapons, why use a less powerful 223 if the rifle is full sized?

but i would love to get a shortened version to use on my SBR lower.

I agree. Though this looks friggin' awesome, it's a sub-standard round. At best it's around 2300 fps and sub-400 ft/lbs of energy. No thanks, I'll stick to my 5.56x45.

chad_quixote · 12-11-2008, 02:36 PM

fancy

12-11-2008, 01:16 PM	#1
Ishpeck XDTalk 4K Member Join Date: Mar 2007 Location: Earth Posts: 4,445	Weirdest AR upper ever Murdoc Online AR Five Seven: 5.7×28mm AR Upper What do you do with your mag well if you've got one of these installed? __________________ I'm not pro gun. I'm pro ARMAMENT! http://www.ishpeck.net/
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12-11-2008, 01:22 PM	#3
StewieGriffin XDTalk 1K Member Join Date: May 2008 Location: Quahog Posts: 1,092	My friend ordered one of these. It's suppose to be delivered today. Only reason why he got the AR is because of this. He has a FN PS90, so he wanted to keep the same caliber. I'll have to ask him about where it ejects when I see him and the set up tomorrow.
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12-11-2008, 01:24 PM	#4
Yuppicide XDTalk 3K Member Join Date: Dec 2006 Location: The People's Gaypublic of Drugafornia Posts: 3,700	nice!!!!!! __________________ *********************************************** ΜΟΛΩΝ ΛΑΒΕ "President Obama has agreed to commit an additional 40,000 troops to fight Fox News." -Jay Leno**
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12-11-2008, 01:40 PM	#5
RoninSteel XDTalk 100 Member Join Date: Oct 2008 Location: KS I-70/I-135 Posts: 345	Seems like an awkward combination there. Access to the magazine could be quite difficult with optics attached. Also, think about firing inside a building with concrete floors in a combat situation. The spent brass being dropped at your feet could be troublesome. __________________ The rifle itself has no moral stature, since it has no will of its own. Naturally, it may be used by evil men for evil purposes, but there are more good men than evil, and while the latter cannot be persuaded to the path of righteousness by propaganda, they can certainly be corrected by good men with rifles. -Jeff Cooper-
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12-11-2008, 01:41 PM	#6
Wild Rice XDTalk 500 Member Join Date: Dec 2007 Posts: 808	Both the PS90 (which I own) and the AR57 (which I don't own) feed from a longitudinal topside 50rd magazine that feeds the rounds via a 90 degree spiral tunnel into the chamber. The action is straight blowback and the AR buffer spring system is used. The casings eject straight down, via the mag well in the case of the AR57. This makes both the PS90 and AR57 completely ambidextrous. The downside is that the casings end up under your feet. They sell a fabric pouch brass catcher for the PS90 and it would be easy to make a similar one for the AR57. Some people have removed the top, follower, and spring from an AR mag to make a metal brass catcher for the AR57, but there is a chance a casing could bounce up into the action. The 5.7x28 is a neat, flat-shooting little round and the PS90's bullpup design is very compact and fun to shoot. The PS90 is fascinating to disassemble due to its ingenious design. The AR57 shown in the link would be restricted due to the short barrel. You would want a 16" AR57 upper. One advantage of the AR57 would be to practice shooting your AR system at an indoor range that does not allow rifle calibers. You could also build an AR57 with a nice match trigger. The bullpup design of the PS90 requires a long trigger bar that makes the trigger somewhat heavy and spongy. Last edited by Wild Rice; 12-11-2008 at 01:44 PM.
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12-11-2008, 01:45 PM	#7
StewieGriffin XDTalk 1K Member Join Date: May 2008 Location: Quahog Posts: 1,092	I emailed my friend about the upper he is about to get, and he sent me this picture... scroll down to the very bottom!
	Share

12-11-2008, 01:56 PM	#8
sourpatch45 XDTalk 4K Member Join Date: Jun 2008 Location: Boise, ID (its boy-see NOT boy-zee!!!) Posts: 4,851	i would love to have one of those for a SBR, but for a full size rifle it kinda defeats the purpose of the 5.7 round which was for smaller weapons, why use a less powerful 223 if the rifle is full sized? but i would love to get a shortened version to use on my SBR lower. __________________ I haven't stopped believing in god. I just stopped beliving he cares. There might be a god, there might not, but i dont think it matters. Either way were on our own.-Jace Wayland If you want to polish your barrel click the link below http://www.xdtalk.com/forums/xdtalk-...ng-thread.html
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12-11-2008, 02:36 PM	#10
chad_quixote XDTalk 1K Member Join Date: Feb 2008 Posts: 1,107	fancy __________________ that all this was anticipated and so you will know that it meant nothing to me.
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