how to hold upper reciever?

[LRRPF52]

There's close to 5.75" clearance between the two lugs.

[mongoosesnipe]

I have used a cheap scope riser with success but if money is not tight and you may build a few more uppers I would invest in a geissele reaction rods http://geissele.com/reactionrod.aspx which keeps the torque off the receiver all together

[customcutter]

Thanks I'll use my 4" UHMW covers for now, I'd rather save the $'s for the Grendel build.

[Tedward]

I have used a cheap scope riser with success but if money is not tight and you may build a few more uppers I would invest in a geissele reaction rods http://geissele.com/reactionrod.aspx which keeps the torque off the receiver all together

That might be good when the barrel is in the upper. For my Mega Arms SBU's, you need to hold the upper in a vise, heat the upper at the threaded barrel nut area and tap the barrel into the upper receiver. The heat expands the Aluminum for the barrel extension to fit into the upper then cools locking it down so tight a barrel nut is essentially just an extra measure and way to hold the hand-guard. I called MEGA Arms when mine didn't fit and that is how Tech Support said to do it. They this also reduces harmonics in the barrel. How true or how much it helps is just opinion I would think. Sort of like a fact that can't be proven.

This is the only upper's Ive ever seen like this, both my SBU and my SBU Side Charge are like that. Some people make the mistake and sand out the upper for the extension to fit. That is a no-no.

But yes, good tool for other applications but I also don't like the idea of putting all that torque on my extension where the bolt has a critical contact surface. Also, what if the upper slid half off the tool extension, you could possible damage the extension on the barrel if it isn't seated all the way. No locking mechanism. . I see it as a possible issue..

[mongoosesnipe]

the question was about dpms slab side which accept barrels just fin at least the ones i have built have and i bedded them with blue lock tite i clamp the upper in a vice via the rail with a cheap riser and torque to hand guard spec as far as not relying on barrel nut to hold the barrel in place unless you are tig welding it to the reviver i would not trust a simple heat cool pressure fit

[NugginFutz]

I have used a cheap scope riser with success but if money is not tight and you may build a few more uppers I would invest in a geissele reaction rods http://geissele.com/reactionrod.aspx which keeps the torque off the receiver all together

^^ This. Steel riser, clamped to the upper rail, has sufficiently facilitated all my slick side's barrel work.

One combination to avoid (in my opinion) is the DPMS slick side and any of the Hogue Freefloat tubes. There are few strap wrenches with the cojones needed to torque those barrel nuts, if they won't align on the first available hole. Because of the thickness of the upper, aggravated by the recessed depth of the holes in the barrel nut, you can't get a barrel wrench to bite on the nut from either the front or the back.

[txgunner00]

I made this out of HDPE (high density polyethylene). Works with any type of flat top upper.

action block2.jpg

action block1.jpg

The halves are held together with 2 screws with the holes over-boared on the work side. This helps with alignment but allows them to slip freely.

[mongoosesnipe]

^^ This. Steel riser, clamped to the upper rail, has sufficiently facilitated all my slick side's barrel work.

One combination to avoid (in my opinion) is the DPMS slick side and any of the Hogue Freefloat tubes. There are few strap wrenches with the cojones needed to torque those barrel nuts, if they won't align on the first available hole. Because of the thickness of the upper, aggravated by the recessed depth of the holes in the barrel nut, you can't get a barrel wrench to bite on the nut from either the front or the back.

Yeah I have never been a fan of the strap wrench for the barrel nut deal with the hogues all my builds have used a real barrel nut of one kind or another

[keystone183]

^^ This. Steel riser, clamped to the upper rail, has sufficiently facilitated all my slick side's barrel work.

One combination to avoid (in my opinion) is the DPMS slick side and any of the Hogue Freefloat tubes. There are few strap wrenches with the cojones needed to torque those barrel nuts, if they won't align on the first available hole. Because of the thickness of the upper, aggravated by the recessed depth of the holes in the barrel nut, you can't get a barrel wrench to bite on the nut from either the front or the back.

This is a big problem, but my frustration was not knowing what i'm torquing the nut to. Alignment issue was fixed easy enough though, by buying a lapping rod, and lapping the receiver a bit.

[NightForce]

Because of the increasing numbers of non milspec upper receivers, I bought a tool that makes so much sense to use making most other methods of securing the upper receiver ...

The Geissele Reaction Rod

[explorecaves]

Because of the increasing numbers of non milspec upper receivers, I bought a tool that makes so much sense to use making most other methods of securing the upper receiver ...

The Geissele Reaction Rod

Ultra-strong rod slips into the upper receiver and gives needed support for barrel changes and parts installation. Makes removal and installation of barrels, flash suppressors, gas blocks, and handguards much easier. Designed to be gripped in a bench vise so that the rod is either horizontal or vertical. The upper receiver is then slid onto the rod and the rod’s integral splines enter the barrel extension and secure the barrel extension from turning, allowing all the torque from barrel nut wrenches to go directly into the barrel extension. Unique design can't mar the barrel’s exterior finish and eliminates the need to remove sights or optics when installing the barrel on the upper receiver.

Or use Brownells… http://www.brownells.com/gunsmith-to...prod27452.aspx

[NightForce]

Or use Brownells… http://www.brownells.com/gunsmith-to...prod27452.aspx

The Brownells is a quality tool but the Geissele rod has a milled flat that can be clamped tightly in a bench vise eliminating movement...

[Tedward]

The Brownells is a quality tool but the Geissele rod has a milled flat that can be clamped tightly in a bench vise eliminating movement...

The Brownells works the opposite. The barrel nut is stationary and the barrel extension is turned, entire upper receiver rotates. It looks like you put your armors wrench in the vise, put the barrel and extension on the upper receiver, place the barrel nut into the armors wrench that is in the vise and then torque. For $30 I'll try the Brownells because if it doesn't help which it should, you can return it.

AWESOME link Explorecaves!!!!

[jurassic]

How do you see when you are lined up on the gas tube hole with the Brownells tool with the barrel hanging upside down?

[explorecaves]

How do you see when you are lined up on the gas tube hole with the Brownells tool with the barrel hanging upside down?

Look through the charging handle slot?