Now that my recent AR re-configure is almost done, I want to buy a lower to start build my next rifle on.
I’ve done some searching, and my natural tendency to “buy local” comes through loud and clear for these folks:
www.usamade-ar15parts.com
Factory is just a few miles from me, and the owner is very active in promoting and supporting local AR shooters, thats worth something right there to me!
I’m wondering if others here are familiar with this operation and what your opinions might be?
I’m curious as that what the “10-32 accurizing screw” is; considering the lower has nothing to do with accuracy. Is it supposed to be something to reduce the slop between the upper and lower?
Good question, I’ll ask them and “get back to you on that, Katie”
my first thought is it is something like an accu-wedge
I’ll bet it presses against the rear takedown lug on the upper to remove any wiggle.
-RD62
Yes the new phenomenon in lowers is set screws to take slop out of the fit to satisfy the crowd that things their 1k dollar AR should fit together at tight as a 50k HH double gun.
I’m buying Belmont an Accuwedge for Christmas.
OP
I tend to stay with established names with components, as I’ve yet to be burned going that route. However, in my limited experience with lowers, I’ve found that as long as they are in spec, they are GTG. Your LPK and Upper should be higher priorities. Getting a “tight” upper and lower fit isn’t necessary, and I’d probably forgoe the screw if i were to purchase one, myself.
Didn’t know it was called an “accurizing screw”, my Quentin Defense lower has this feature.
I posted that question at Carolina Shooters Forum, where the company is a sponsor.
The post got several replys before the company President chimed in, including this one:
I’m not sure what screw you were originally referring to, but there is no such thing as an accurizing screw in an AR.
A tighter lower to upper receiver doesn’t make an AR more accurate. It simply eliminates what some people consider to be excessive wobble.
An adjustment screw for trigger preset doesn’t make an AR more accurate. It simply removes what some people deem excessive preset.
The only things that will make an AR more accurate are a good barrel, plenty of practice, and good ammo that is matched to the barrel.
Following that reply, came this one from Mr. Barnes:
You are correct sir!
We call it an “accurizing” screw , because that it is what is has always been refered to in industry …although it is a misleading/incorrect description.
Yes …accuracy is contributed to-controlled by upper to barrel fit…not lower to upper fit.Screw used to take up “CREEP” of trigger is also USAMTU trick…and it lessens amount you have to pull trigger to drop the hammer…so , this CAN be an accuracy improver,especially if using high magnification optics and shooting for group size…that is elementary.
What is first thing bolt gun guys do to improve /shrink groups??They do a trigger job(reduce creep and lighten up pull…and then reduce overtravel) as well as steel bed action to stock…and freefloat barrel. Those are the most common anyway…that produce the biggest results.We install this feature(like other premium grade lowers have) to tighten up feel from upper to lower when assembling.Those who know better ,(and most consumers ,with all due respect ,do not)realize Uppers are made within a tolerance range and so are Lowers …and because of this tolerancing of parts you can get an “in tolerance” machined upper or lower …and get more play than the ones assembled yesterday…that were also well within tolerances …IT IS tHE NATURE OF THE DESIGN!!!Those who say a little play is an indicator of poor /unacceptable quality ,do not understand the way the weapon works …or how Eugene Stoner designed it /meant for it to be made.Ever heard of an ACCUWEDGE??? Why do they exist??? Because issue has been around for many years ,and they( Accuwedge) had the first commercially available product to address it .I have seen Colts (the worst) Bushmasters/DPMS/Olympics/LMT’s /Stag/Rock River/ as well as a lot of no names …and they ALL exhibited a certain amount of play/looseness. Ours are no better/no worse…because we machine to the SAME TOLERANCES.That is also why some of these very folks tell us we machine a GOOD QUALITY/IN SPEC product that is indicative of common industry players.
If you shoot a high mag scope …reducing upper to lower play might help tighten up groups because of less wiggle of upper once on target .(your heartbeat/breathing can affect reticle movement in this situation) …and so can loose fitting upper to lower…it can effect group size , but it is not a “direct” effect as mentioned .
Weapon will exhibit a looser feeling the more rounds you put through it ,the more you disassemble it to clean it…and this screw gives you the option of tightening it up during the life of product.It is an old USAMTU (US Army Marksmanship Training Unit )trick that gunsmiths/armorers have been doing for YEARS…but no one until the last few years ,has been including it on production models.It is a method taught by most gunsmithing /armorers courses,as well as other “steel bed” methods,as taught by Mark Hunt at Montgomery Community College.
I did not come up with the idea …we just decided to include it as a standard feature in our lowers …along with hole for detent pin/spring for rear takedown pin being tapped for a set screw …so you can do stock changes with out losing /dealing with detent pin/spring.These are just two of the things that make ours a Premium grade lower receiver in many peoples eyes…and since we do not machine uppers …yet- it gives our customers the option of mating with ANY upper in industry ,while maintaining a tight fit.
Thanks for listening.
Now we know!!!
Ummm, this is very far from accurate. You need a solid lower as a platform for the upper. The lower also contains the Trigger which is vital to accuracy as well…so you can see that the lower does effect accuracy.
Here’s the Cliff Notes on Mr. Barnes’ grammatically creative reply:
“Beacuse some people think it’s neat.”
LOL…why the hell did the Cliff Notes come after the long, boring story. Heck, your a mod…you got secret powers and stuff:D
Eh, it depends on what you mean by “accuracy”.
The lower will have no impact on mechanical accuracy unless something in the lower is really messed up and impacts consistency.
If you ate talking about the individual’s ability to be consistently precise, a good trigger will definately help, but less than precision optics will help, or to ake it in another direction- the most significant issue will be individual skill. Since these things are nigh impossible to qualify and have little to nothing to do with the individual items one is throwing cash at, we tend to limit the discussion topics to those things that do directly apply to mechanical precision and consistency, things like barrels, handguards, barrel nut torque, trueness of the face of the upper, and things like that.
Umm, no, I’m not seeing it. Please, elaborate on how an in-spec lower contributes to the mechanical accuracy of an AR-15.
Does a loose or sloppy fitting lower add to accuracy?
I wasn’t necessarily limiting my comments to strictly Mechanical accuracy and I understand where your statements are coming from.
These firearms are not mounted arms and few are probably going to see a Benchrest outside of sighting in and or load development.
On a side note I admit that my experience with the AR platform is somewhat limited as the majority of my shooting experience with one has been Varmint hunting.
That said I have never seen or handled an accurized AR with a sloppy Upper/Lower.
Does a loose or sloppy fitting lower add to accuracy?
Define “accuracy” here.
Lower receivers that are in spec and have the wiggle common to every AR-15 I’ve handled will neither add nor detract from the mechanical accuracy of the rifle.
Elements beyond the mechanical that make things easier on the “shooter” are highly subjective and dependent largely upon the “shooter” in question, assuming we’re dealing with quality components at the onset.
I’m simply not seeing how a good shooter’s groups on paper will change between a standard fitting lower and one that’s been modified to fit more tightly, all other things being equal.
If anyone has some data to the contrary and the testing procedure used, I’d like to see it.
No data and no testing on AR platforms, but it stands to reason that anything that changes the way the rifle recoils from shot to shot could affect accuracy. If the horizontal slop bears left on one shot and right on the next, it stands to reason that the path of the bullet is affected to some degree.
On FALs upper/lower slop has a major affect on accuracy. I’ve tightened up more than a few and the results have always been positive for me. This is easy to understand with the irons since the the rear sight is on the lower receiver - but I see similar results when an optic is used. (I replaced the barrel on one rifle five times before I discovered the problem was in excessive horizontal slop between the upper and lower receivers.)
One would think that moving the sighting system to the upper receiver would immediately solve the problem, but that was not my experience.
Hey Uncle
I have one of the lowers with a S&W upper in my very, very little experience (outside of the Corps) it is GTG I don’t see any problems with it and there are no malfunctions. The main man at BPM will give you a tour of the facility and show you them being made if you would like (thats what he offered to do for me when I questioned about my lower) My lower came with the gun in a trade.
He’s offered me a tour as well, and I fully intend to take him up on the offer! Andrew is a stand-up guy and very supportive of local shooters and shooting scene.
Hello everyone, I am brand new to the site and really have no idea how forums like this are suppose to work. Anyway, I am looking to build and my question is mating uppers and lowers. I am looking at getting a colt le6920 lower that is brand new. I am new to the build scene and I was wondering if you can put together different brands of lowers and uppers like the colt that I am planning to get. I know that the trigger control group pins are a different size than most but that shouldn’t have anything to do with putting the two together, right? Thanks for any insight you might have.