Accuwedge....Worth it?

Well, I'm thinking. If the front pin[that connects both upper to lower], "acts as an axis"/"vertical pivot point". Et there is some very minor "upward" movement[because the two halve's are not tight @ the rear pin] upon firing a rd....

The "tip" of the barrel, would flex upward, & the breech end would flex downward. Thus raising point of impact?

edit; Similar to a Teeter-Totter
 
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Quote:
We have one in each of ours. I find it interesting in that without, wouldn't this be like having a loose action to stock fit??? The upper is floating around somewhere as the bullet is traveling the barrel, if this is exactly the same each firing then no accuracy change but if the floating or movement is different shouldn't this change point of impact an amount. I know this is rally evident in rimfire even with a well set up Br gun held differently shot to shot.



I used to be a believer that the accuwedge "must" increase accuracy due to the above logic.

I've thought about this many times and I believe the difference lies in the fact that in a bolt gun, the bolt locks up in the action. The action is tied to stock. If you put different pressure on the stock from shot to shot, your in turn changing the stress on the action itself. Different stresses on the action itself will in fact affect accuracy. That is why bedding a bolt gun helps. It minimizes the "warping" of the action. Free float a bolt gun and bed the action, you've got a pretty solid foundation.

On an AR style rifle, the bolt locks up in the barrel extension. The barrel / extension is held into the upper receiver by the barrel nut. As stiff as the upper receiver is at the point where the barrel is held in place by the barrel nut (especially with the barrel nut in place), your not going to get any "warping" or enough stress on the extension to change the point of impact. In fact, you've got a 360 deg. bed around the the barrel extension.

Different pressure holding on an AR would seem to be taken up by the slop between the upper and lower. (No matter how you hold it, the barrel / barrel extension should be under the same stress all the time.) Therefore, the slop between the two (upper/lower) really doesn't matter.

Now, on a standard hand guard AR (fixed to the barrel) accuracy will definately be affected by different pressures on the barrel/handguard due to barrel harmonics. But again, that has no connection between the upper and lower not being a tight fit. Most varmint ARs are free floated so this isn't an issue.

Edited BC my mind gets ahead of my fingers....
 
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The reason accuracy isnt affected by a loose fit, is that the sights and barrel are lined up regaurdless of the lower. If your sights are on, where your sights are is where your bullet will go.
DaFUnk
 
Hitman,
That's interesting, because I didn't need one in my Bushmaster Varmint Special, but I put one in the DPMS rifle that DTech made for me.
John
 
I put them in an A2 carbine, A2 National Match and a 20" flat top. All of these were Bushies. I was never really happy with NM as the sight tower was cocked on the rifle and the windage was way off. After trying to that fixed from Bushmaster, I couldn't get anywhere with them, I decided I would just sell my Bushmasters. I haven't looked back and I have been VERY satisfied with my RRA's and the few DPMS's that own or have owned. Like I said has just been my experience with the acu-wedges. I think I still have a few in case I ever needed to use them.
 
Good Reading,,

I was wondering the same as well. How would a loose lower/upper fit affect accuracy?

Kirby makes a few good points. And it would seem that since the scope and barrel are inline with the POA, then a loose lower should have little effect on POI.

I was also wondering about the force of the hammer hitting the pin. Wouldn't this sudden impact on the pin, cause the upper to change POA, as the hammer slams into the pin? Since there would be a small amount of slop with the upper/lower. Would any sudden movement, from the hammer hitting the pin, cause the upper to move ever so slightly, and cause larger groups on the target?

Of course I suppose as long as the upper was held into the rest, and stable, then the hammer/pin connecting would be irrelevant?

Also, I am very curious how many of you have used the AR15 in competitions, as to what type of rest have or do you use that would be the most accurate.

Considering that upright and hand held being the worst. Whats the most accurate setup someone, like myself and others would use to ensure accuracy?

Do most of you use a simple front rest, with sandbags in the rear?

Bipods?

Any pictures and details of your setup, would sure be a help to us all.

Cheers
Thanks
LC
 
Very interesting thread.

Quote:
Dtech: The "slop" between the upper and lower receiver is very annoying, but not a cause for inaccuracy. That being said, I used a similar product. I just don't like the feel of any "wiggle" while I'm handling an AR.



Mike, what "similar product" do you use?

Quote:
Kirby: Why an AR, will not shoot tighter if the [slop] is gone? Please explain, so I'll understand. Thanks.




Quote:
LEN: We have one in each of ours. I find it interesting in that without, wouldn't this be like having a loose action to stock fit??? The upper is floating around somewhere as the bullet is traveling the barrel, if this is exactly the same each firing then no accuracy change but if the floating or movement is different shouldn't this change point of impact an amount. I know this is rally evident in rimfire even with a well set up Br gun held differently shot to shot.



I am willing to take Mike's (and others) word that the slop does not harm accuracy because of his (their) extensive experience with the AR platform, but I am with Kirby and Len in that I don't understand why. Hopefully someone can explain how it would be different than shooting a bolt gun with a loose tang screw.


Regards,
hm
 
I'm not sure why. The lock up on a bolt gun is limited to the receiver too. Maybe it has to do with the fact that because of the stock configuration an AR recoils back in a straight line instead of pushing the muzzle up? I don't know, it seems like it should affect accuracy. /ubbthreads/images/graemlins/confused1.gif

We know for sure through many years of competition experience that loose fit doesn't affect accuracy, but on the other hand the wedges only cost a few bucks, and they do stop any "rattle", so why not? /ubbthreads/images/graemlins/cool.gif
 
Thanks for the knowledge, guys. I already bought the accuwedge, so I'll install it as soon as the wife isn't home to see the rifle she doesn't know that I own. It sounds like it can't hurt anything.
Jazzball
 
HM, the device I use is much like the Accu-wedge, but is not quite as hard. The accu-wedge is made large enough so that it will fit pretty much any upper-lower combination. In most cases I've found that they need to be trimmed in order to close the upper onto the lower. The ones the I've been using are firm, but you can squeeze the receivers together without trimming.

Someone had mentioned foam ear-plugs. That is exactly what I used for years. EAR brand seems to have enough "spring" to them to do the job.

I've never really given "why" a loose fit doesn't seem to effect accuracy, but I would have to believe that any normal "hold" and cheek-weld would bind the upper and lower sufficiently.

I would guess that if there were significant play between receivers you could probably cause inaccuracy by holding the rifle in an unnatural way: Say if you shot single-shot and rested the empty mag-well on the sand-bag or front rest. The upper receiver would have no external force acting on it. When you "bench" an AR you would normally have the FF tube on the front rest, and you cheek pressing down on the butt-stock. This combination would bind the two receivers, disallowing movement.
 
Quote:
When you "bench" an AR you would normally have the FF tube on the front rest, and you cheek pressing down on the butt-stock. This combination would bind the two receivers, disallowing movement.



Makes sense, now. The same would be true whether shooting from a bench, sticks, bipod or even prone/sitting w/sling as in NM competition mentioned by nmleon.

Thanks for the explanation, Mike. /ubbthreads/images/graemlins/grinning-smiley-003.gif

Regards,
hm
 
Since I got my Oly .243WSSM upper. Et attached it onto my Bushmaster V-Match lower. I noticed a [little slop]. I believed this [minute slop, perhaps a 1/64"?] would effect my accuracy. Specifically, on long range coyote.

Fall time, I used [timber]camo tape to bind the two halve's tightly together, above the rear pin = [no slop]. Come Winter snowfly, I taped my rifle White. Also accomplishing the same thing = tight.

Since I read about the "wedge". Et I wanted the ability to open my rife @ anytime. For bolt/breech cleaning. This little plug fit the bill. No more taping.
 
The slop in my dpms was right at 1/64 as well. No it never was a problem, i'm just one of those guys who figures that if i can hear that little noise at a foot away from my ear, so can that yodie at 100+ yds away, ... no he probably can't, i know that , just one less thing to think about when i'm sneaking around trying to get that shot. blue
 
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