Dumb question: Does an AR lower really affect accuracy?
- Thread starter Slateman
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Trigger has more to do with accuracy then the lower. If you need proof though build the most expensive lower you can find into a 17 Remington, bring it up here and let’s have a shootoff. winner gets both rifles.
Lock time on AR are much longer than bolt action so a really good trigger and trigger control is crucial for accuracy but that the only part the lower has to do with it. Spent money on a well built upper and a trigger but the lower receiver itself can be average.
Cheers
Cheers
I’ve heard that the lower is just a box to hold parts. As long as it’s in spec it’s good. Now, the parts it holds are another story.
Not sure how true that is but it seems if the specs are correct it doesn’t matter what is on the outside.
Not sure how true that is but it seems if the specs are correct it doesn’t matter what is on the outside.
It must fit well enough to the upper that the upper doesn't shift upon hammer drop. Thanks DPMS for that lesson.
IMO not much. Loose or tight don't seem to matter much besides the fact you like them tight and not rattling around.
But I'm not going to say never either, but to me if the trigger, hammer , spring, and fit of these parts are the same, no.
The barrel & scope/sight is one, so it comes to hammer, trigger and speed of hammer fall and trigger creep, pull etc.
But I'm not going to say never either, but to me if the trigger, hammer , spring, and fit of these parts are the same, no.
The barrel & scope/sight is one, so it comes to hammer, trigger and speed of hammer fall and trigger creep, pull etc.
As long as the lower is in spec and all the measurements are correct. The main thing a higher quality lower does is reduce play and hopefully make the cycle of operations smoother. Which in turn can lead to more accuracy. Less friction on the system. Probably wont make a whole lot of difference, but it feels smooth.
I think that the Lower fit is largely cosmetic, as long as there's no binding going on. IMHO, the crucial factor in Upper/Lower fit is about slop in the mounting pins. As long as the features that depend on the lower (particularly that pin fit, and a good trigger) work, the accuracy comes out of the Upper, IMHO.
Greg
Greg
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Until evidence is provided to the contrary, I agree with MSTN. Of course it matters.
On many bolt action rifles, torque values on the action screw have a noticeable affect on accuracy... torque values... in that case, the gun has no slip whatsoever, and even the amount of tension (with zero slop) affects accuracy. Thus, backing the screw all the way out until there is actual movement would affect accuracy even more.
This is exacerbated further by different shooting positions. A loaded bipod on an AR can result in the rear of the upper receiver raising up, while offhand shooting sees the rear of the upper seated against the lower. Vastly different harmonics of the upper upon firing.
NOBODY in their right mind would accept a chassis that allowed their bolt gun to wiggle...
That’s what we ALL do when using standard AR configurations...
On many bolt action rifles, torque values on the action screw have a noticeable affect on accuracy... torque values... in that case, the gun has no slip whatsoever, and even the amount of tension (with zero slop) affects accuracy. Thus, backing the screw all the way out until there is actual movement would affect accuracy even more.
This is exacerbated further by different shooting positions. A loaded bipod on an AR can result in the rear of the upper receiver raising up, while offhand shooting sees the rear of the upper seated against the lower. Vastly different harmonics of the upper upon firing.
NOBODY in their right mind would accept a chassis that allowed their bolt gun to wiggle...
That’s what we ALL do when using standard AR configurations...
Not necessarily but I get your point. However, considering it from an engineering standpoint, material density, mass, natural frequencies and other properties of the materials can affect the outcome. The physical properties may be significantly different between aluminum and composite, depending on the composite used. For instance when comparing aluminum, 7075 billet and forged lowers are the same material but have different natural frequencies and other properties and will produce different results. More importantly it is the mechanical resonance of the "system" that has more affect than a single component, so it must be analyzed more as a system. If I were to replace a forged lower on my rifle with a billet lower, both being good quality material, the differences would only be noticeable in a laboratory type environment, not in a practical sense. With all that said, does it matter in our use? Not really. I think we adapt and adjust accordingly to the firearm we are using at the time. I know my rifles are more accurate then I am capable of achieving so for me I just purchase from quality manufacturers. Of course I am speaking in generalities in this post because there are just too many variables to be definitive.
In reading a lot about this it seems like a lot of controversial things can impact accuracy in AR's. Not surprising given all that can impact accuracy in a bolt gun (action screw torque, bedding quality, etc.) Probably partly controversial by the very nature most people can't shoot them as well as bolt action guns due to the mechanics. That said if you read lots on what the guys do that build competition uppers, and the AMU etc. you frequently hear them talk about the same things like bedding the barrel extension, facing the upper receiver, either hand picking upper/lower combos so they are super right, or bedding them, hand fitting gas tube alignment, not pinning gas blocks, using a heavier upper than mil-spec, using a super rigid handguard, ensuring front to back bolt play tighter than spec, etc.
Ask a precision rifle shooter to loosen his trigger guard or trigger screws, or action screws and shoot groups and they'll look at you like you are crazy, to me this isn't that different.
Some might say those things are useless, but at the end of the day I've always been in the camp that if they don't hurt anything, there's no penalty to trying them aside the time it takes, and if they help even a little bit it's worth it. When it comes to precision having things loose is almost always worse than having things tight.
Ask a precision rifle shooter to loosen his trigger guard or trigger screws, or action screws and shoot groups and they'll look at you like you are crazy, to me this isn't that different.
Some might say those things are useless, but at the end of the day I've always been in the camp that if they don't hurt anything, there's no penalty to trying them aside the time it takes, and if they help even a little bit it's worth it. When it comes to precision having things loose is almost always worse than having things tight.
Plastic/composite lowers are/were out there to buy, but not very popular because of durability issues.
But they will hold the things that count on a lower-trigger, hammer/spring, so they might work for people that don't use them much, but you still have the flexing that screws with trigger/hammer movement which might become inconsistent.
And for the bolt action comparisons that were made here , there is no comparison, a bolt gun is a totally different animal.
Held in with screws that apply torque, a striker that's contained in the bolt, the ass end also held on with a screw.
Bedding the action is key so the screws do NOT bend anything when tightened up.
An AR barreled action just sits atop a lower, that's it, no pressure applied either. The upper has way more to do with accuracy than worrying about how the lower fit's, worry instead about the trigger/hammer/pull/creep/repeatability.
I have one of those plumb crazy (polymer) lowers. Someone send me a high dollar lower and I’ll do a side by side comparison.. we could talk about this till the cows come home and not get anywhere because both camps are right, to a extent..
