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9/22/2017 12:11:25 AM
Posted: 10/2/2005 12:50:02 AM EDT
I recently built a rifle with a RRA lower ant J&T upper. It shoots wonderfully, and so far has been 100% reliability wise. The only issue I have is with the fit of the upper and lower reciever. Ther is a bit of play, and it makes the gun feel cheap. Is this normal with AR's? How much play is considered excessive?
Link Posted: 10/2/2005 1:35:51 AM EDT
I use the same set up and the results has been a good fit so far , however we all know even the best brand names can make mistakes with thier spec's, unless there is a great deal of play, I would try putting an accuwedge in first this will most likely solve your problem, J&T and rockriver are both good to deal with , If you have a bad out of spec problem I'am sure they will help resolve it for you
Link Posted: 10/2/2005 5:02:28 AM EDT

Originally Posted By mgw24:
Ther is a bit of play, and it makes the gun feel cheap. Is this normal with AR's?

That is normal.

How much play is considered excessive?

Excessive is when it affects its function and accuracy - which usually is NEVER the case. So it really all depends upon your comfort level.

Link Posted: 10/2/2005 5:07:28 AM EDT
[Last Edit: 10/2/2005 5:09:15 AM EDT by I-M-A-WMD]
Try the accu-wedge as suggested.

One of my favorite firearms that I've ever had the pleasure of owning/shooting was an old Colt SP1. I could probably have walked some wide horizontal figure eights @ 50 yards if I just held the lower stationary and wobbled the upper while firing. Basically, play between the receivers is more common than it should be so it could be labeled "normal". But let's just say it's disconcerting just as you have discovered.

Sly

ETA: The receiver play didn't effect the accuracy per-se as the upper is connected w/ the sights. So as long as the sights are where you want the bullet placed, it'll get there. It's just harder to be accurate when you're thinking of the wobbling receivers instead of focusing on your next shot.
Link Posted: 10/2/2005 5:19:36 AM EDT
The upper/lower fit on my carbine is the exact opposite. I have a flattop from CMMG (manufacturer unk) and a Stag lower and the fit is so bloody tight that it requires a flathead screwdriver to pry the rear takedown pin out of it's recess, and the butt of the screwdriver to pound it back in when putting the carbine back together. It has become easier to do the more that I have fired it, but it's still a chore. I really hope that this question doesn't hijack the thread, but I am curious if any of you folks have a remedy for the exact opposite "problem" of the above shooter?
Link Posted: 10/2/2005 5:32:49 AM EDT
[Last Edit: 10/2/2005 3:20:54 PM EDT by pathfinder74]
If you've ever handled an M16 out of the arms room you know what play is. Issue rifles are ridden hard and rattle beyond belief. Odds are the play you're experiencing is pretty minor.

The Accuwedge will more than likely put an end to you woes.

Am I dreaming, or wasn't there another "device" that stops play.. not an accuwedge although it might go in the same place as one.
Link Posted: 10/2/2005 10:02:16 AM EDT
[Last Edit: 10/2/2005 10:03:29 AM EDT by mgw24]
For some reason, I cannot get the recievers to go together at all when I try to put in the accu-wedge. I think I'm doing it right, according to the included instructions. I would have to put SIGNIFICANT force on the recievers to get them to close, so I gave up. Does anyone have a picture of a properly installed accu-wedge, or have some suggestions?

I also have the device (can't remember the name) that replaces the rear takedown pin and pulls the recievers together. The only problem with that is it looks like I would need a hex wrench to take the rifle down. I like being able to just push the pin with my thumb to take down the rifle.

cjk1- can you do some "light" sanding on the area that is causing the bind?
Link Posted: 10/2/2005 11:13:20 AM EDT

Originally Posted By mgw24:
For some reason, I cannot get the recievers to go together at all when I try to put in the accu-wedge. I think I'm doing it right, according to the included instructions. I would have to put SIGNIFICANT force on the recievers to get them to close, so I gave up. Does anyone have a picture of a properly installed accu-wedge, or have some suggestions?

I also have the device (can't remember the name) that replaces the rear takedown pin and pulls the recievers together. The only problem with that is it looks like I would need a hex wrench to take the rifle down. I like being able to just push the pin with my thumb to take down the rifle.

cjk1- can you do some "light" sanding on the area that is causing the bind?



I had that problem with my first accuwedge and then compared it to a buddy of mine's. First he told me to stop being a pussy then he couldnt get the upper/lower to fit. we compared and the base of mine was a bit taller.
Link Posted: 10/2/2005 11:26:02 AM EDT
Trim the bottom of the accuwedge, with a razor blade or sharp thin bladed knife, till it's the appropriate size to allow the upper to fit snugly on the lower. Use the trial an error approch by trimming off a little at a time then test fitting till you have the correct size.
Link Posted: 10/2/2005 2:48:55 PM EDT
[Last Edit: 10/2/2005 2:53:28 PM EDT by I-M-A-WMD]

Trim the bottom of the accuwedge, with a razor blade or sharp thin bladed knife, till it's the appropriate size to allow the upper to fit snugly on the lower. Use the trial an error approch by trimming off a little at a time then test fitting till you have the correct size.


When I've used the Accu-wedge, I've found it takes some brute strength to get the lowers mated enough for me to push the rear TD pin in. Once closed, I have to use a hamme/punch to tap the TD pin out for disassembly. I'm of the opinion that SlickRider is steering you in the right direction here. With some judicious trimming you should be good to go.


Originally Posted By cjk1:
The upper/lower fit on my carbine is the exact opposite. I have a flattop from CMMG (manufacturer unk) and a Stag lower and the fit is so bloody tight that it requires a flathead screwdriver to pry the rear takedown pin out of it's recess, and the butt of the screwdriver to pound it back in when putting the carbine back together. It has become easier to do the more that I have fired it, but it's still a chore. I really hope that this question doesn't hijack the thread, but I am curious if any of you folks have a remedy for the exact opposite "problem" of the above shooter?



How old is your upper/lower? Have you excersized them a bit to see if things will settle or has the upper/lower rarely been seperated?

First have you liberally oiled the rear take down pin? If your rear takedown pin just seems like it won't go in the hole, it may be caused by friction between the inside of the takedown hole and rear TD pin. If you have tried that, or it appears that the holes just don't line up properly- I'd recommend you either get used to using tools to seperate the receivers or head to the "trouble shooting" forums here and ask for others w/ actual experience. I'd offer some suggestions, but since I've never personally attempted corrective measures for what you describe, it'd be better to seek a general consensus than one guy's guess in an unrelated post.

If I could also make a suggestion... Don't use a flat screwdriver to pry the rear takedown pin. Use a punch, preferrably polymer, and a hammer to tap out the TD pin. (You might scratch your receiver on the RH side of the frame w/a screw driver but of course if you're not careful, a hammer could do damage as well.

Hope it works out for you.

Sly

Edited for clarification.
Link Posted: 10/2/2005 3:17:13 PM EDT

Originally Posted By SlickRider:
Trim the bottom of the accuwedge, with a razor blade or sharp thin bladed knife, till it's the appropriate size to allow the upper to fit snugly on the lower. Use the trial an error approch by trimming off a little at a time then test fitting till you have the correct size.



Good idea! I never thought of that. I'll give it a shot.

As always, thanks a lot guys!
Link Posted: 10/2/2005 4:02:48 PM EDT
[Last Edit: 10/2/2005 4:04:09 PM EDT by boltcatch]
Sometimes I wonder what people mean by "a bit of play". My first M16A2 was wobbly as all hell, but it was a tack driver and was in no way a "cheap" gun.

If it really bothers you, there are fixes as have been described. Otherwise, it isn't really a functional problem. (if anything, it makes take-down easier).
Link Posted: 10/2/2005 6:56:51 PM EDT

Originally Posted By boltcatch:
Sometimes I wonder what people mean by "a bit of play". My first M16A2 was wobbly as all hell, but it was a tack driver and was in no way a "cheap" gun.

If it really bothers you, there are fixes as have been described. Otherwise, it isn't really a functional problem. (if anything, it makes take-down easier).



Agree. I just don't like it....

Anyway, I fixed it by just cutting a slice off of the bottom of the accu-wedge and putting the slice in the rifle. I just hope it stays put... It feels like it should though.

Link Posted: 10/2/2005 8:09:39 PM EDT
You don't need to mess with Accuwedges. A cheaper, simpler, nearly invisible, and just as effective method to eliminate the upper/lower slop is to slip a .625 x .500 x .062 rubber o-ring over the front lug of your upper. Reassemble the upper on the lower, close things up, and no more slop. You can buy about a dozen o-rings for the price of an Accuwedge.

Here's a pic with the o-ring installed......

Link Posted: 10/3/2005 6:05:53 AM EDT

Originally Posted By Russ4777:
You don't need to mess with Accuwedges. A cheaper, simpler, nearly invisible, and just as effective method to eliminate the upper/lower slop is to slip a .625 x .500 x .062 rubber o-ring over the front lug of your upper. Reassemble the upper on the lower, close things up, and no more slop. You can buy about a dozen o-rings for the price of an Accuwedge.

Here's a pic with the o-ring installed......

www.hunt101.com/img/306786.jpg



Now that's an awesome tip!!
Link Posted: 10/3/2005 7:34:20 AM EDT

Originally Posted By pathfinder74:


Am I dreaming, or wasn't there another "device" that stops play.. not an accuwedge although it might go in the same place as one.



You might be referring to the JP Enterprises Tension Pin. Replaces the rear takedown pin.
Link Posted: 10/3/2005 8:29:20 AM EDT

Originally Posted By yankee2:

Originally Posted By pathfinder74:


Am I dreaming, or wasn't there another "device" that stops play.. not an accuwedge although it might go in the same place as one.



You might be referring to the JP Enterprises Tension Pin. Replaces the rear takedown pin.



Thought there was something else.
Link Posted: 10/3/2005 12:22:49 PM EDT

Originally Posted By yankee2:

Originally Posted By pathfinder74:


Am I dreaming, or wasn't there another "device" that stops play.. not an accuwedge although it might go in the same place as one.



You might be referring to the JP Enterprises Tension Pin. Replaces the rear takedown pin.



I have one of those, but when I realized I would need an hex wrench for takedown, I didn't install it.

What about Shrink Wrap on the upper reciever "posts" (for lack of proper terminology) that the takedown pins go in to. Or, how about the hard rubber stuff that you would use on a tool handle (don't know what that is called either).

Link Posted: 10/3/2005 12:57:24 PM EDT



place the rifle across your legs [while seated]. the buffer tube/stock area goes on one leg, the handguards go on the other. press down on the upper receiver just before the CH. you'll be able to push the upper down on even the tightest accuwedges.

i don't use them anymore though. play is normal between the receivers and does not affect accuracy.


Link Posted: 10/3/2005 1:25:06 PM EDT
Mine have a little movement,dosent effect function or reliabilty.Just think when you shoulder the rifle standard or with a grip your putting upward pressure any way pushing the upper to the lower.Feel isnt a factor for me and would rather there be a little play and the upper and lower seperate with no tools quickly.
Link Posted: 10/3/2005 2:06:17 PM EDT

Originally Posted By mgw24:

Originally Posted By yankee2:

Originally Posted By pathfinder74:


Am I dreaming, or wasn't there another "device" that stops play.. not an accuwedge although it might go in the same place as one.



You might be referring to the JP Enterprises Tension Pin. Replaces the rear takedown pin.



I have one of those, but when I realized I would need an hex wrench for takedown, I didn't install it.

What about Shrink Wrap on the upper reciever "posts" (for lack of proper terminology) that the takedown pins go in to. Or, how about the hard rubber stuff that you would use on a tool handle (don't know what that is called either).




....and back to Russ's post. The O-ring is the way to go if ya gotta do it. I use them, and have had zero problems. They just need to be replaced occaisionally. Dumped my JP Tension pin, and glad I did. It has zero utility on a rifle you'd have to work on in the field. JMHO.
Link Posted: 10/3/2005 8:42:14 PM EDT
[Last Edit: 10/3/2005 8:44:57 PM EDT by mgw24]
Cool, I'll give that a shot.

Where is the best place to get the orings?

Thanks!

Link Posted: 10/3/2005 10:17:38 PM EDT
You can usually find rubber O-Rings at a well stocked auto parts store like Kragens, Shuckers (sp), or NAPA. Even plumbing supply houses usually carry them.
Link Posted: 10/4/2005 5:08:41 PM EDT
+1 on the accu-wedge , I have them in all of my AR's and love them !
Link Posted: 10/4/2005 6:38:16 PM EDT
Armalite's Tech Note section is your friend:

www.armalite.com/library/techNotes/tnote55.htm

Some excerpts below from TECHNICAL NOTE 55: RECEIVER TIGHTNESS

"It is also possible to reduce movement by inserting materials such as paper, rubber, or epoxy somewhere between the receivers and creating a tight fit or bind. Many commercial customers use a common rubbery device claimed to improve accuracy, and the Army Marksmanship Unit often uses a bit of epoxy. The AMU Armorers advise that this procedure doesn’t improve accuracy, but it makes the shooter feel more confident about their rifle."

"The AMU Armorers are correct. Formal testing conducted at Rodman Laboratories in the 1970s verified that accuracy wasn’t affected by normal receiver tolerances. The fact is that the bullet exits the bore before movement of the receivers produces a measurable effect. "

"Modern manufacturing processes are unable to produce to dimensions that both allow full interchangeability AND prevent all movement in all cases. "

and

"Receivers will normally exhibit a certain amount of looseness. This is normal and will not affect accuracy. Shooters may reduce the movement by insertion of a small amount of material between the receivers to improve the feel of the rifle, but it won’t improve accuracy."
Link Posted: 10/4/2005 6:56:20 PM EDT
coolness... Thanks!
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