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Posted: 2/2/2013 9:46:29 PM EDT
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All,
Please check out this photo below of this dissipator upper I'm trying to piece together. I have 3 questions about 3 specific parts numbered 1, 2, and 3: 
1. What is the industry term for this part? 2. This is a special shaped handguard cap for this type of build, what is this called? 3. To add this type of front sight tower with the two pins on the bottom, does something need to be cut into my barrel to allow the pins the slide over the barrel? Currently the barrel is stock from factory. I have my barrel, gas block, gas tube, and barrel nut. To make sure I'm not missing anything please correct me if I'm wrong, but I will need the following: - whatever is on top of the barrel nut - the special shaped handguard cap - the F marked front sight tower - the gas tube pin from the sight tower to handguard cap Thanks for the help. |
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Quoted:
All, Please check out this photo below of this dissipator upper I'm trying to piece together. I have 3 questions about 3 specific parts numbered 1, 2, and 3: https://5d7i1a.bn1.livefilestore.com/y1petwPgpLUZeWeJUMzGPGEN1LstzlC_3kpzTaEtJ_hFl83gPDTRw-qdvDBlLtCYad9Fu6trv8mit8efvA789FTfPdSvQsWGSPF/22.jpg?psid=1 1. What is the industry term for this part? 2. This is a special shaped handguard cap for this type of build, what is this called? 3. To add this type of front sight tower with the two pins on the bottom, does something need to be cut into my barrel to allow the pins the slide over the barrel? Currently the barrel is stock from factory. I have my barrel, gas block, gas tube, and barrel nut. To make sure I'm not missing anything please correct me if I'm wrong, but I will need the following: - whatever is on top of the barrel nut - the special shaped handguard cap - the F marked front sight tower - the gas tube pin from the sight tower to handguard cap Thanks for the help. 1. Delta Ring 2. Triangle End cap or you can get round end caps. 3. Knock out the pins, take off the flash suppressor and slide it over. |
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Cool thanks!
So the front sight tower can go on the barrel with the pins without any machining? Does the barrel need to be a certain type of barrel to keep the handguard cap in place? I saw this piece, http://www.midwayusa.com/product/748130/doublestar-dissipator-handguard-adapter-block-ar-15-standard-barrel-750-inside-diameter-aluminum-matte but wasn't sure what it is used for. Thanks for any help. - Wes |
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Quoted:
Cool thanks! So the front sight tower can go on the barrel with the pins without any machining? Does the barrel need to be a certain type of barrel to keep the handguard cap in place? I saw this piece, http://www.midwayusa.com/product/748130/doublestar-dissipator-handguard-adapter-block-ar-15-standard-barrel-750-inside-diameter-aluminum-matte but wasn't sure what it is used for. Thanks for any help. - Wes Tell me what you want to use the endcap for do you have a set of forends in mind to put on? |
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Yes I just want to put the Magpul MOE rifle length handguards on it with a fixed sight tower.
This is the barrel I have: http://www.cmmginc.com/product_p/55d520b.htm 16" gov profile barrel I built this with a Laure FF rail but didn't like so I'm taking all that stuff off and putting handguards on it and fixed sight tower. Just not sure of all the parts I need. |
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Yes I just want to put the Magpul MOE rifle length handguards on it with a fixed sight tower. This is the barrel I have: http://www.cmmginc.com/product_p/55d520b.htm 16" gov profile barrel I built this with a Laure FF rail but didn't like so I'm taking all that stuff off and putting handguards on it and fixed sight tower. Just not sure of all the parts I need. Magpul hand guards work with triangle or round end caps. |
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Quoted:
Yes I just want to put the Magpul MOE rifle length handguards on it with a fixed sight tower. This is the barrel I have: http://www.cmmginc.com/product_p/55d520b.htm 16" gov profile barrel I built this with a Laure FF rail but didn't like so I'm taking all that stuff off and putting handguards on it and fixed sight tower. Just not sure of all the parts I need. Magpul hand guards work with triangle or round end caps. Good to know, thank you. My last question is about my barrel then. No machining will have to be done to the barrel to get a fixed sight tower on it? And does anything besides the gas tube insert pin from the sight tower to the handguard cap need to be installed to keep the handguard cap from moving? |
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Yes I just want to put the Magpul MOE rifle length handguards on it with a fixed sight tower. This is the barrel I have: http://www.cmmginc.com/product_p/55d520b.htm 16" gov profile barrel I built this with a Laure FF rail but didn't like so I'm taking all that stuff off and putting handguards on it and fixed sight tower. Just not sure of all the parts I need. Magpul hand guards work with triangle or round end caps. Good to know, thank you. My last question is about my barrel then. No machining will have to be done to the barrel to get a fixed sight tower on it? And does anything besides the gas tube insert pin from the sight tower to the handguard cap need to be installed to keep the handguard cap from moving? you are taking the A2 sight off for what ? |
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Just to be clear, OP you want the Front sight pinned like the one in the picture. It sounds like your barrel is not set up for a fixed front sight base. You would need a shop to align the front sight and drill through the FSB (front sight base) as well as through the barrel at the same time to allow for pins to be put through it.
This tends to be kind of expensive. A easier alternative is to use a Armalite or ARMS 41B Clamp on sight. These use two cross bolts that clamp the sight around the barrel and are very stout. The ARMS sells for around $150, and that does seem like a lot, but most shops will charge you around $90 just to mount the sight (ie you supply the virgin front sight). The advantage is the modularity of it. If you get tired of the Dissy you can remove the front sight and there will be no holes to cover up. If you decide you want a more traditional set up, you can remove the low pro gas block and use the clamp on in it's place as a functioning gas block as well. |
Here is an alternative to the short piece of gas tube to hold the handguard cap. No drilling is necessary to tap the existing hole.
If you look at the bottom of a sight base, you will see that they've drilled a hole for the gas port. It is already the right size for a 10-24 tap. Get a #27 drill bit and a 10-24 tap and drill and tap through the bayonet mount and you now have a sight base that can be used to fill your needs. I dimple my barrels at the set screws so my sight base can't move, but that's totally up to you. You also want to get your barrel first, so that you can size your components to the barrel. Some are .750 at the gas port, some are .625. Mine was .749 at the gas port, and .742 at the "rifle length". |
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Quoted:
Here is an alternative to the short piece of gas tube to hold the handguard cap. No drilling is necessary to tap the existing hole. http://i1276.photobucket.com/albums/y471/chevypowrd/AR%20stuff/73AF448D-5A06-4BF0-B6C5-93C8BC828641-830-00000188E0F573C1_zps0d0a6abd.jpg If you look at the bottom of a sight base, you will see that they've drilled a hole for the gas port. It is already the right size for a 10-24 tap. Get a #27 drill bit and a 10-24 tap and drill and tap through the bayonet mount and you now have a sight base that can be used to fill your needs. I dimple my barrels at the set screws so my sight base can't move, but that's totally up to you. You also want to get your barrel first, so that you can size your components to the barrel. Some are .750 at the gas port, some are .625. Mine was .749 at the gas port, and .742 at the "rifle length". Keep in mind that some handguards require a skinny section to hold the cap in place in lue of the gas tube. The KAC M5 that I have on mine required a small roll pin be used so the handguard would lock in. The fact that most barrels will be slightly smaller than the gas port collar, is also where a clamp on style front sight shines. |
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