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Posted: 5/28/2014 3:19:46 AM EDT
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Hello
My barrel/rail comes in today. Just wondering if I really need an upper vice block, or if I can just rotate the upper 90deg so the top rail/mating face to the lower receiver gets the vice jaws. Will that damage my receiver even if I use cardboard for protection? And can I put a muzzle device on the end of my barrel doing it that way? Or will the bending moment be too great down a 16" barrel? Any help would be appreciated! Edit - First time AR builder, very novice when it comes to ARs. However I did manage to build my lower w/o losing a detent or needing a magazine vice block. |
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Quoted:
Yes you can turn it on it's side and clamp it between some soft jaws or just pin it to the lower receiver if you have a lower block. DO NOT do this unless you want to crack your upper receiver. The pins between the upper lower were not made to take stress like this. Clamp it in your vice on it's side with some plastic inserts. Or buy this. Then you have NOTHING to worry about. http://www.botach.com/products/kley-zion-armors-ar15-m4-barrel-spline-socket-rod.html |
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You need upper receiver block.
I use the clam shell type with T insert. Your barrel needs to be torque between 30 and 90 ft. lbs. You can crack or distort the upper receiver unless you have it clamped. http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/bench-vise-blocks/ar-15-m16-upper-receiver-action-block-prod22385.aspx Dave N |
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Cobalt: An upper receiver block is the one essential tool for assembling an upper. Most people use a clamshell type receiver block. I use the DPMS Claw (a tight-fitting plastic block that goes inside the receiver), see link below. IMO, you can skip the torque wrench (I don't use one). You can even gin up some kind of tabletop clamping apparatus to substitute for the bench vise. Some handguards (e.g., MI's SS gen 2 models) come with a supplied wrench adapter, so you may not need a GI armorers wrench. My most recent barrel nut install (for an SLR Solo handguard) tightened with a simple crescent wrench.
However, you must have some way of protecting the upper receiver from the torque applied to the barrel nut. Long ago, GI armorers used the old method of clamping the barrel just forward of the chamber in a bench vise, with wooden or metal blocks, while tightening the nut. That still works in a pinch, but the modern method is with a proper upper receiver block. You shouldn't start you upper assembly without one. A cracked receiver is NFG! - CW http://www.midwayusa.com/product/730930/dpms-upper-receiver-action-block-ar-15-delrin?cm_vc=ProductFinding |
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I turned it 90 degrees and put a book between the rail and vice, and another book between the bottom of the receiver and the vice. Worked fine for me and I was able to torque everything to spec.
Obviously a vice block is preferred but I didn't have the time to wait or I would've missed the range trip. |
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Quoted: You need upper receiver block. I use the clam shell type with T insert. Your barrel needs to be torque between 30 and 90 ft. lbs. You can crack or distort the upper receiver unless you have it clamped. http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/bench-vise-blocks/ar-15-m16-upper-receiver-action-block-prod22385.aspx Dave N This is the same block I use, and it's has worked well for me, mostly. However, I'm going to be switching to the Geissele reaction rod in the near future. The reason being is I've found with some rail systems the clam shell vise block interferes with the rail. I saw this with both Troy and Geissele rails. That made installation a bit tough, where as the reaction rod slides inside the upper receiver, and locks into the receiver extension. The only downside to the latter is that it's $100. |
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Look you're going to develop the same black-rifle disease the rest of us have once you've dropped the hammer on that first round of that first build. Unless the zombies are clamoring at your door invest the $35 or so and get a clam-shell upper holder and do it right. In this case it's "don't buy once, cry once" if you screw it up. Can you do it other ways? Sure you can, but this is a good place to be smart.
And for the love of GOD Almighty do not use a block that just pins the upper to it. As mentioned before the pin holes were never meant for that sort of rotational force. Anyone recommending that should be ashamed of themselves. I also highly recommend an upper lapping tool and compound if you've invested in a good barrel. It assures a perfect barrel extension to upper mating so that once the barrel nut is torqued the pressure applied to the barrel extension flange is even all the way around. It's stupid easy to use and I've yet to do an upper that couldn't use it. Also, when you torque the barrel, less is more. Stay to the minimum 3-35 lb/ft side of the range. No need to get macho here as more torque can lead to less accuracy. Other than that good luck and enjoy the new member of the family! |
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