Posted: 7/12/2011 4:29:24 PM EDT
I have a set of the brand new Magpul BUIS mounted on my CMMG dedicated .22 upper. When I depress one of the side paddles the front BUIS will not fully spring up. It's almost as if the catch on the opposite side isn't moving clear allowing it to spring up. Has anyone else had this issue? Is there an easy fix, or do they need to be returned?  |
| Looking at your second picture it looks like the release is hitting on your "Gas Block". I know that yours is a dedicated .22 upper so the "Gas Block" is useless, but I think that the post will still have to be up too far for your front sight picture to look "right". I know when I put mine on my DPMS 7.62 Sportical the front sight post was above the 'ears' on the sight. I didn't read the disclaimer from Magpul stating not to use MBUS on Gas Blocks due to heat issues, which is a moot point on your setup, and improper sight picture, which I believe would still be a problem on your setup. |
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Quoted: Looking at your second picture it looks like the release is hitting on your "Gas Block". I know that yours is a dedicated .22 upper so the "Gas Block" is useless, but I think that the post will still have to be up too far for your front sight picture to look "right". I know when I put mine on my DPMS 7.62 Sportical the front sight post was above the 'ears' on the sight. I didn't read the disclaimer from Magpul stating not to use MBUS on Gas Blocks due to heat issues, which is a moot point on your setup, and improper sight picture, which I believe would still be a problem on your setup. Thanks for the reply. The sight will pop up if you depress the large button on top or pull both side levers down together. If you just depress one side release or the other, the whole release mechanism cants to the side you depressed and the other side won't release. The gas block is receiver height so I'm not sure I understand the sight picture issue. |
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You absolutely should NOT mount a magpul BUIS to a gas block, they will tell you tell you the same if you email or call them. It will melt your buis. Get a troy folder for the front and never look back. EDIT: I'm not sure if you will have the melting issue if you are running only .22lr, but for .223 it will melt if you get it really hot (only takes a few mags in quick succession to get the block really really hot). http://www.ar15.com/forums/topic.html?b=2&f=124&t=196610 |
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Quoted: You absolutely should NOT mount a magpul BUIS to a gas block, they will tell you tell you the same if you email or call them. It will melt your buis. Get a troy folder for the front and never look back. EDIT: I'm not sure if you will have the melting issue if you are running only .22lr, but for .223 it will melt if you get it really hot (only takes a few mags in quick succession to get the block really really hot). http://www.ar15.com/forums/topic.html?b=2&f=124&t=196610 It's a dedicated .22 upper receiver so the gas block is purely cosmetic. |
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Quoted: Quoted: You absolutely should NOT mount a magpul BUIS to a gas block, they will tell you tell you the same if you email or call them. It will melt your buis. Get a troy folder for the front and never look back. EDIT: I'm not sure if you will have the melting issue if you are running only .22lr, but for .223 it will melt if you get it really hot (only takes a few mags in quick succession to get the block really really hot). http://www.ar15.com/forums/topic.html?b=2&f=124&t=196610 It's a dedicated .22 upper receiver so the gas block is purely cosmetic. Oh...dedicated = blowback and no functional gas system? Sorry, I overlooked that for sure. Carry on gentlemen. |
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Quoted: Just noticed that your sights have slotted screws. Mine both have hex head screws. Did you buy them from a reputable source. ETA: and no Magpul Logo. Sure they are not fake or Airsoft and that is why you're getting the cant. I got them from my local LE distributor. I would be absolutely shocked if they were the airsoft version. |
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Quoted:
Quoted:
Just noticed that your sights have slotted screws. Mine both have hex head screws. Did you buy them from a reputable source. ETA: and no Magpul Logo. Sure they are not fake or Airsoft and that is why you're getting the cant. I got them from my local LE distributor. I would be absolutely shocked if they were the airsoft version. I just went and checked mine out. Look at the large area on top where you push down to activate the flip up sight. On yours there are lines etched there On mine there is the Magpul Logo with no lines. Mine also doesn't say MBUS on the ear of the sight. The hex head screw is machined with Magpul. Magpul does have an Airsoft line. I think it is Magpul Training. Edit: Magpul PTS |
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Quoted: Just noticed that your sights have slotted screws. Mine both have hex head screws. Did you buy them from a reputable source. ETA: and no Magpul Logo. Sure they are not fake or Airsoft and that is why you're getting the cant. My new buis from Primary Arms have the slotted screws, they arrived yesterday. I think magpul may have changed their parts a bit, the instructions indicate a slotted screw also. This makes sense, in the field, you could find or fabricate a slot head tool, but an allen screw would be much harder. Look here at this link, the gen2 magpul buis shown on Magpul's website have slot screws and the design is identical to what I have: http://store.magpul.com/product/MAG248/45 |
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Quoted:
Just noticed that your sights have slotted screws. Mine both have hex head screws. Did you buy them from a reputable source. ETA: and no Magpul Logo. Sure they are not fake or Airsoft and that is why you're getting the cant. Jsucraig, you have a Gen 1, the OP has a Gen 2. The new ones do come with a slotted screw, and redesigned looks. It is authentic. As for the operation issue, you should be able to flip it open from just one side, all mine do, so i suspect what others suspect, you may be hitting up against the gas block. Try moving the sight to the receiver, and see if it works on that rail. |
| The rear sight has the Magpul logo but not the front. The packaging makes no mention of it being PTS or whatever the training brand is. I tightened down the screws as tight as they'll go and it helps a bit. If I push the side release hard and fast it will pop up now. I also wonder if the picatinny rail on the CMMG is completely spec. After all this is just a plinking upper and the sights will come up so it's not a huge deal. I was just wondering if this was a common occurrence. Thanks for all the replies fellas. |