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+--- Thread: Have you ever heard of bending an Upper receiver? (/showthread.php?tid=7545)
Have you ever heard of bending an Upper receiver? - Klem - 03-18-2014
Butterbean Wrote:^^^^ Yup ^^^^^
Never used spray rubber but sounds like the go.
I often use thin cardboard. It's abrasive enough to grip, but not mar the finish.
Have also seen rosin used in machine shops. I believe you can get it as grip enhancers for tennis and baseball (never used it myself).
Also seen an old-timer gunsmith use a thin piece of leather.
Have you ever heard of bending an Upper receiver? - explorecaves - 03-19-2014
Bicycle inner tube. Cut what length you want, apply a little double sided tape to the vice adaptor and stick the rubber to it so it doesn't fall off.
Have you ever heard of bending an Upper receiver? - waveslayer - 03-19-2014
LRRPF52 Wrote:What make of receiver is it?
It was a RRA, it is definitely bent. no cracks though. I have a clamp style vise now for the receiver. Tonight I get to put it all back together.
Have you ever heard of bending an Upper receiver? - LRRPF52 - 03-19-2014
waveslayer Wrote:It was a RRA, it is definitely bent. no cracks though. I have a clamp style vise now for the receiver. Tonight I get to put it all back together.
Funny. The last two I have seen broken were both...RRA. I wonder what aluminum they're using.
And gun shop owners wonder why I choose to select my own components, rather than buy their preferred dealer status vismods on the wall.
Have you ever heard of bending an Upper receiver? - radian23 - 03-19-2014
I'm not sure if its the aluminum used but the fact that they locktite their barrel nuts.
Have you ever heard of bending an Upper receiver? - burkew23 - 05-29-2014
LRRPF52 Wrote:Some will, many won't. Use cutting board as vice insulators, and do it sideways, so the rail is against one flat, and the bottom of the upper is against the other.
![[Image: upperclamped.jpg]](http://kevinholman.com/byor/ar10noveske/upperclamped.jpg)
LRRPF52,
Is that ar15 upper? I've been searching for a good billet upper w/o forward assist, mind sharing who makes that one?
Have you ever heard of bending an Upper receiver? - cory - 05-29-2014
I believe Mark at PF makes one.
Have you ever heard of bending an Upper receiver? - burkew23 - 05-29-2014
Thanks for the heads up Cory. I can't seem to find it on their website, not sure if they've discontinued it or not. I'll email Mark to find out.
Have you ever heard of bending an Upper receiver? - Rust - 06-12-2014
LRRPF52 Wrote:Some will, many won't. Use cutting board as vice insulators, and do it sideways, so the rail is against one flat, and the bottom of the upper is against the other.
I know you've got a lot of experience working with AR's LRRPF52, but I've personally sprung/cracked a receiver with almost the exact same set up. I think it allows the potential for to much torque to be transferred into the thin wall below the ejection port. I've since moved to a clamshell type which supports the solid walls just behind the barrel nut threads.
Have you ever heard of bending an Upper receiver? - cst - 06-12-2014
how come more people arent talking about the Geissele reaction rod?
Have you ever heard of bending an Upper receiver? - waveslayer - 06-12-2014
cst Wrote:how come more people arent talking about the Geissele reaction rod?
Because the lack of knowledge about it. I never knew it was out until this happened.
Have you ever heard of bending an Upper receiver? - jurassic - 06-12-2014
waveslayer Wrote:Because the lack of knowledge about it. I never knew it was out until this happened.
They work really well, better than everything else I've tried, but expensive. I have one, pure eye candy, the machining and finish is fantastic.
Have you ever heard of bending an Upper receiver? - Wheelhorse - 08-15-2014
Here is what I use.
http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/barrel-tools/ar-15-m16-308-ar-barrel-extension-torque-tools-prod27452.aspx?avs|Make_3=AR-15/M4
About the same as the Geissele reaction rod but a lot cheaper. Clamp the armors tool in a good vise, insert this in the lugs and there is no stress on the body of the receiver at all.
Have you ever heard of bending an Upper receiver? - Ullr - 08-15-2014
Quote:About the same as the Geissele reaction rod but a lot cheaper. Clamp the armors tool in a good vise, insert this in the lugs and there is no stress on the receiver at all.
That is not true. You can't torque the receiver to the barrel nut without applying torque to the receiver and the barrel nut. The same stress is applied to the receiver, it is just all being applied at the barrel pin notch (unless you're also gluing the barrel into the receiver, in which case some of the torque is transferred to the receiver via that glue joint). Why focusing the receiver torque on that notch instead of spreading it out over a larger area of the receiver is considered preferable is unclear to me.
The reaction rod type tools unstress the receiver when working on muzzle devices by isolating the torque to the barrel extension/barrel interface. The torque is then borne by friction on the threads and shear stress on the barrel pin. Far better to clamp the barrel in that circumstance, which isolates the torque to the barrel/clamp interface and removes the possibility of shearing the pin and unscrewing the barrel from the extension.
Have you ever heard of bending an Upper receiver? - Wheelhorse - 08-15-2014
Of course there is torque applied directly at the threads. Without that, the barrel would fall off.
As for the pin notch, I put grease between the barrel and the nut so any twisting of the barrel is minimized, and there is certainly no more stress on that area than in any other method. Torque is torque regardless what it passes through. With the reaction rod design, the receiver doesn't have to flex until the correct torque is reached. Any chain will break at its weakest link and the photos in this thread, indicate where that link is.
It's the rest of the receiver this tool keeps stress off of, what's at the barrel nut is unchanged.
My intent here was to bring this particular tool into the discussion, and probably should have left my personal opinion out of the post because obviously, it differs from yours.
BTW, I edited my op to say "body of the receiver", which I thought was the subject of this thread anyway.
As far as I know, Mr. Geissele came up with this idea, and he is no dummy.
Have you ever heard of bending an Upper receiver? - Wheelhorse - 08-15-2014
Ullr Wrote:That is not true. You can't torque the receiver to the barrel nut without applying torque to the receiver and the barrel nut. The same stress is applied to the receiver, it is just all being applied at the barrel pin notch (unless you're also gluing the barrel into the receiver, in which case some of the torque is transferred to the receiver via that glue joint). Why focusing the receiver torque on that notch instead of spreading it out over a larger area of the receiver is considered preferable is unclear to me.Of course there is torque applied directly at the threads. Without that, the barrel would fall off.
The reaction rod type tools unstress the receiver when working on muzzle devices by isolating the torque to the barrel extension/barrel interface. The torque is then borne by friction on the threads and shear stress on the barrel pin. Far better to clamp the barrel in that circumstance, which isolates the torque to the barrel/clamp interface and removes the possibility of shearing the pin and unscrewing the barrel from the extension.
As for the pin notch, I put grease between the barrel and the nut so any twisting of the barrel is minimized, and there is certainly no more stress on that area than with any other method. Torque is torque regardless what it passes through. With the reaction rod design, the receiver doesn't have to flex until the correct torque is reached. Any chain will break at its weakest link and the photos in this thread, indicate where that link is.
My intent here was to bring this particular tool into the discussion, and perhaps should have left my personal opinion out of the post because obviously, it differs from yours.
BTW, I edited my op to say "body of the receiver", which I thought was the subject of this thread anyway.
As far as I know, Mr. Geissele came up with this idea. Does anyone consider him a dummy?
Have you ever heard of bending an Upper receiver? - Ullr - 08-17-2014
Quote:Of course there is torque applied directly at the threads.
In this case, "directly at the threads" means directly to the barrel pin and receiver notch.
Quote:As for the pin notch, I put grease between the barrel and the nut so any twisting of the barrel is minimized,...
Greasing the interface between the barrel and the nut reduces torque transfer between the barrel and the nut. That has no bearing on the pin notch, which is part of the receiver. Nor does it have any bearing on the torque transfer between the barrel and the receiver , which occurs principally via that notch. You cannot reduce torque transfer from the barrel to the receiver if you are going to use a reaction rod type tool. Transferring torque to the receiver via the barrel is how the reaction rod works.
Quote:... and there is certainly no more stress on that area than with any other method.
Of course there is. The typical clamshell or receiver-insert type tools do not directly stress the barrel at all. The only twisting force that the barrel (and thus the barrel pin and notch) receives when removing a barrel nut using those tools is by friction transfer from the barrel nut to the face of the barrel extension. As you point out, that minimal force is further reduced by the barrel nut grease. The resulting force is small, and that small force is what the barrel pin and notch were designed to resist.
Using a reaction rod tool, the 30-80 ft-lbs of barrel nut/receiver torque is being applied principally to that notch by that pin. Similarly, that same torque (in magnitude - the direction is opposite) is typically applied to the barrel nut via larger notches by a wrench with more and larger pins. Given that I have broken the 3/16 steel pins on barrel wrenches and stripped notches on steel barrel nuts while attempting to remove stuck barrel nuts, I wonder at the advisability of performing that operation via a single 1/8 barrel pin and matching receiver notch. Wrenches and nuts are cheaper than receivers and barrels.
Quote:Torque is torque regardless what it passes through.
Indeed. And that is my point. Contrary to your previous assertion (now edited away ...) it is not the case that the receiver is not stressed at all when using a reaction rod tool. Rather the receiver is stressed exactly the same amount. The difference is that the stress which creates the torque is concentrated on a much smaller area of the receiver. That has some potential benefits, as you point out. It also has some potential drawbacks.
Quote:My intent here was to bring this particular tool into the discussion,...
And here we are, discussing that particular tool. Mission accomplished
Quote:BTW, I edited my op to say "body of the receiver", which I thought was the subject of this thread anyway.
And you changed the text of this post as well. The point of my OP was to correct the error of the now edited statement...
The subject of the thread is damaging receivers when removing hard stuck barrel nuts. For the reasons stated above, the reaction rod type tools would seem to bring that risk to that task.
Good discussion.
Have you ever heard of bending an Upper receiver? - Wheelhorse - 08-17-2014
I would like to try if I may, to put into words what I think is going on when moving the barrel nut on our beloved rifles.
When using the reaction rod, all the torque necessary to turn the barrel nut is confined directly in the threads and the nut, and I stand by my statement that the receiver is not stressed except in that area.
With the clamshell block the torque necessary to turn the nut, must all be transmitted through the receiver until the barrel nut does what you want, and this is how they get damaged. Transmitting this through the receiver doesn't lessen this torque in anyway as suggested, because it still must be created for the nut to move, and the weakest link is what breaks.
I really see no reason to tighten these to the upper end of the specs anyway. If something bad is gonna happen, that's probably where it will happen at.
I usually pull them to around 40 ft lbs and if it's pretty far from the gas tube hole lining up, I lap a little material from the face of the receiver and recheck until everything lines up at a torque value I'm comfortable with.
BTW, with the Brownel's tool, the torque wrench is connected at the exact center of the tool so the reading indicated will be correct, unlike a torque wrench connected away from the center as on a armorers tool.
Thats about all I can think of, hopefully some of it is correct.
Have you ever heard of bending an Upper receiver? - montana - 08-17-2014
The Department Of The Army Technical Manual TM 9-1005-249-34 copy 1968 instructs using a aluminum barrel vice jaws clamp similar to stevegun1 posted on this thread. I have used both the clam shell and barrel vice methods with out any issues. The barrel extension tool like the Brownells or the Geissle seems to be very similar to the barrel clamp method as far as stress concerns to the upper receiver. I use an upper insert to mitigate any stress related warpage when using a clam shell, "my personal favorite method". Using the receiver inserts with pins to install a barrel as LRRP52 has stated in this post should never be used for installing a barrel as they were not designed for this application.
Have you ever heard of bending an Upper receiver? - Klem - 08-18-2014
We are trying to remove the frame of the receiver from being in between two opposing directions of force.
If you use the nylon clamshells or two pieces of cutting board then the forward end of the receiver-frame becomes a link in the chain between a rigid vise and the torque wrench.
The weakest link will be the first to distort and eventually break but hopefully the torque setting is reached before permanent damage is done. There may be some elasticity in the frame that it returns to the same dimensions after being flexed but on a macroscopic level that will be unlikely. At what point does this flexing affect reliability and accuracy is the applied question.
The Brownells' torque and Gieselle Reaction Rods allows the potentially weak receiver-frame to be removed from the chain. The torque goes from the wrench through the rod, to the barrel extension to the barrel nut, to the rigid vise. There's a couple of different ways you can use these rods but it's all the same; torque does not go through the receiver-frame to the next link in the chain.
Another way of removing the receiver from the equation is to use a barrel vise. Clamp a barrel vise as close to the torque point as possible and again, the receiver frame is removed from the chain.