It's a p. well documented fact that many rounds have a parabolic trajectory. Some even have a left/right arc at certain distances. The gyroscopic forces on the projectile are p. significant and cannot be ignored here.
[QUOTE=Mr. Bleak;39558676]I wasn't even referring to the specific example about that rifle, just sight elevation and bullet drop in general.
Sorry for trying to be informative, I guess it's obvious that to everyone that parabolic trajectory is due to sight elevation.[/QUOTE]
I am dumb too then
You guys realize that I did offer a physical explanation in two parts with sources that specify why ammunition from a rifled barrel accelerates upwards against the force of gravity for the first 100 meters or so, correct? Again, this is coming from the University of Hawaii Physics Department, the source I offered on the Magnus Affect (which is related to, but no direct correalation with, Centripetal acceleration; but air pressure).
You're both right, but you have to consider F(net) = ma, where a is the net acceleration, the m is obviously the stabilized mass, and Force is the total force acting on the object in a given direction-vector. Your projectile experiences an upward force from the Magnus affect as it pierces through the air with high pressure beneath and low above, causing the spin of the bullet to direct the motion forward (torque) and to have the air pressure move it upwards (high to low air). As the projectiles slows, the mass stabilizes along a central axis, and a maximum height from this lift-force is achieved, the particle's lift force goes to zero, and the only force (not counting frictional drag due to air) acting on it is gravitational attraction towards the earth.
Also, sorry if this is another TL;DR again, but I'm just trying to help explain what is in-fact going on with these ballistics, since this is exactly what I want to do with my life.
[editline]12th February 2013[/editline]
[QUOTE=Birdman101;39558228]You guys prob. already knew this but the guy at cabellas told me that New York classifies anything with even the option of having a bayonette as an "ASSALT WEPIN!!1!".
My hundred dollar 86-year-old bolt action rifle is an assault rifle. hahah, have fun with that NY.[/QUOTE]
That's some grade-A crap, right there; honestly. But here in VA, after the crime in CT, vendors at the gun shops and gun shows were so paranoid that they refused to serve and speak with me when I asked questions about their AR-15s because I'm not twenty-one. (In VA, Assault rifles, not including NFA-3 class weapons, are considered 'Long Rifles' unless their barrel length is below 16"; and thus I'm perfectly legal in my state to buy them, but the guys would have nothing to do with me. Thanks a lot -name withheld-.)
I had a gun that would fire upward before dropping down. :v:
My Colt Navy, some dumbass took "Press fit" as "SMASH IT AS HARD AS YOU CAN!" until the front sight pushed into the barrel, made the ball tumble as well as spin so it'd climb a bit before dropping. Aim at the ground next to a guy and hit him in the teeth with that thing, but it's all better now.
[QUOTE=BFG9000;39558875]NO SHIT
I'm clearly asking when it becomes significant[/QUOTE]
I forgot to address this while I was on earlier, sorry. What you're referring to is where the bullet slows due to air resistance to a point where it's less-than affective on target. For all weapons it's different, and I'd have to research more; but for .308 it's between 800m and 1km depending on powder type, burn rate, and match grade. .30-06 is a touch longer between 900m and 1.1km; while we haven't quite been able to tell truly where the .50 BMG reaches yet (or atleast, I don't have any knowledge of round-about estimations, though someone else here might), so I couldn't really answer where it becomes inefficient. The .50 BMG hits with the same amount of force at around one-mile that a .30-06 does at about 200 yards; but that's still after a mile drop, and assuming you can out-smart mother nature, defeat her two to four cross-winds she throws in your way, and can have an optic with enough power to see the target.
[QUOTE=mastoner20;39554323]Remington produces the selective fire (Military, LEO) variants. Also, I could go much, much further; but I think I've demonstrated enough with that list and my general posting in this thread that I'm a gun nut who would love to, one day, own atleast one of every type of modern firearm available. Granted, my career path makes it possible; though highly unlikely.
Also, please forgive my stupidity; but RCMP?[/QUOTE]
There is one problem, Remington does not make the ACR for the public, even their semi-auto variants. You will never be able to get one, which is a shame, because their quality is far above the Bushmaster ACRs. Bushmaster makes the civilian variants, and they are not that great. They have terrible issues with the quick release barrel systems staying tight. Bushmaster didn't take the time to work the problems out when they got the design from Magpul, but Remington did. Unfortunately, Remington is solely in the LE/Military market with them.
Even including Remington though, the Scar is a far superior platform to the ACR, especially at the same price point. I still don't understand how Bushmaster manages to sell any ACRs with the Scar on the market. The problem is, the ACR doesn't do anything that an AR-15 can't, and in all honesty, the same thing can be said for the Scar. The one thing the Scar has going is the 7.62 variants. That is probably the best piston driven battle rifle you will ever be able to find.
EDIT: Even if your career path could make it possible, I would still say that it is unlikely you would see one. No LE department, military, etc will buy just one example of a rifle, they would buy them in lots. There are better options for the same price and cheaper, so it's unlikely any agency would buy them in a such a lot (there are currently no agencies in the U.S. that field ACRs). Even if they did, something that expensive would likely remain in an armory when off-duty.
[QUOTE=mastoner20;39560454]You guys realize that I did offer a physical explanation in two parts with sources that specify why ammunition from a rifled barrel accelerates upwards against the force of gravity for the first 100 meters or so, correct? Again, this is coming from the University of Hawaii Physics Department, the source I offered on the Magnus Affect (which is related to, but no direct correalation with, Centripetal acceleration; but air pressure).
You're both right, but you have to consider F(net) = ma, where a is the net acceleration, the m is obviously the stabilized mass, and Force is the total force acting on the object in a given direction-vector. Your projectile experiences an upward force from the Magnus affect as it pierces through the air with high pressure beneath and low above, causing the spin of the bullet to direct the motion forward (torque) and to have the air pressure move it upwards (high to low air). As the projectiles slows, the mass stabilizes along a central axis, and a maximum height from this lift-force is achieved, the particle's lift force goes to zero, and the only force (not counting frictional drag due to air) acting on it is gravitational attraction towards the earth.
Also, sorry if this is another TL;DR again, but I'm just trying to help explain what is in-fact going on with these ballistics, since this is exactly what I want to do with my life.
[editline]12th February 2013[/editline]
That's some grade-A crap, right there; honestly. But here in VA, after the crime in CT, vendors at the gun shops and gun shows were so paranoid that they refused to serve and speak with me when I asked questions about their AR-15s because I'm not twenty-one. (In VA, Assault rifles, not including NFA-3 class weapons, are considered 'Long Rifles' unless their barrel length is below 16"; and thus I'm perfectly legal in my state to buy them, but the guys would have nothing to do with me. Thanks a lot -name withheld-.)[/QUOTE]
The Magnus Affect only applies with wind blowing perpendicular to the bullet, and depending on wind direction and bullet spin direction, it can apply a force either downwards or upwards. It's really not relevant and there is stall a force being applied downwards on the bullet
[editline]13th February 2013[/editline]
[QUOTE=mastoner20;39560736]I forgot to address this while I was on earlier, sorry. What you're referring to is where the bullet slows due to air resistance to a point where it's less-than affective on target. For all weapons it's different, and I'd have to research more; but for .308 it's between 800m and 1km depending on powder type, burn rate, and match grade. .30-06 is a touch longer between 900m and 1.1km; while we haven't quite been able to tell truly where the .50 BMG reaches yet (or atleast, I don't have any knowledge of round-about estimations, though someone else here might), so I couldn't really answer where it becomes inefficient. The .50 BMG hits with the same amount of force at around one-mile that a .30-06 does at about 200 yards; but that's still after a mile drop, and assuming you can out-smart mother nature, defeat her two to four cross-winds she throws in your way, and can have an optic with enough power to see the target.[/QUOTE]
If it's got half the energy of a .22lr at impact it's still lethal. .308s will still kill past 2000m, possibly further
[editline]13th February 2013[/editline]
Using the JBM Ballistics Calculator ([url]http://www.jbmballistics.com/[/url]). I got this:
.308, 185gr Berger Match VLD @ 800ms^-1 (the sort of velocity you'd get using that bullet weight out of a long barrel)
At 3000m it still has 270J of energy, more than a .22lr at point blank, though you'd be compensating for more than 300MOA of drop
[QUOTE=Mr. Foster;39562255]
-Argument against my wishlist-[/QUOTE]
I'm perfectly aware they make Selective Fire only variant. That's what I was referring to for a reason. Also, I put it on my wishlist because of that reason; it would be rare. As for getting into the 'second kind of cool' as TNP puts it; I'm going off of what I want, and what I like. I like the firearm for what it does and for the ambi-bolt release, which the SCAR does not offer. I also like the Magpul roots the weapon is derived from (The Magpul Massada Prototype).
[QUOTE=download;39562424]-counter argument for the Magnus Effect-[/QUOTE]
I'll concede for the moment, because you're right. I did a stupid vector calculation error and had the cross of the two vectors not cancel but add. But I'm still not satisfied that the reason for the projectile rise is an arbitrarily small theta creating a MOA rise of about two mils for .308 (180 gr traveling 800m/s² if someone wants to recheck alongside and tell me if I'm being an idiot, again) at 100 yards (109.4m).
Let me check again and see if I'm using the wrong angle difference between the bore and the optics focal point, or if I'm calculating the angle wrong to begin with, but I'm not getting matching results to what I should be if it was the angle as you specified.
EDIT to your other point I didn't see: I didn't mean to imply it couldn't kill (sorry, rereading because I was in a hurry to get to class, I may have worded as such); but that it would be impractical to use the .308 past about 800 to 900 meters, because of the extreme MOA drop. In theory, so long as you're not going beyond whatever parabolic property distance a 45° angle would be (whatever the arctan would be. A very large number, to say the least), it would still be lethal, as the projectile would regain the lost momentum on its way back to earth, minus the affects of drag, which would be far greater because of the yaw in the bullet, the loss of rotational velocity, et cet. I'm saying with optics available and without having to hold a larger mil-hold than what the general sight already offers.
Also, kudos for the link. I've been doing hand-calculations during my physics lectures because I hate the topic we're in right now... haha.
[QUOTE=mastoner20;39562820]I'm perfectly aware they make Selective Fire only variant. That's what I was referring to for a reason. Also, I put it on my wishlist because of that reason; it would be rare. As for getting into the 'second kind of cool' as TNP puts it; I'm going off of what I want, and what I like. I like the firearm for what it does and for the ambi-bolt release, which the SCAR does not offer. I also like the Magpul roots the weapon is derived from (The Magpul Massada Prototype).[/QUOTE]
Remington doesn't make just select-fire variants, they make semi-automatic variants as well that could be sold to the public, but that isn't the problem though. Despite Remington and Bushmaster being both part of the Freedom Group, Bushmaster has the civilian market contract for the ACR and Remington has the LE/Military contract. Bushmaster bought Remington and had them do the LE/Military variants, which is why the guns are such higher in quality. Remington has a much more extensive background when it comes to LE/Military. Bushmaster...not so much. Basically, business politics is the reason why you can't buy the Remington variant.
As far as the Scar, all of the controls on the gun are ambi, except for the bolt release. Despite this, there are many cheap and effective aftermarket options to remedy that. Also, while it's roots are the Masada, the Bushmaster and Remington variants of the ACR are far from the original design (which was superior by all means). The mistake that Magpul made was giving Bushmaster the development rights instead of just manufacturing rights. Also, another fun fact, the Remington ACR is more far off from the original Masada than the Bushmaster ACR is. Other than looks, the Remington ACR is effectively not the same gun.
I can understand wanting something for the appeal, but not when it's technically a pointless design. This is where our opinions will differ. It's like the Five-seveN. The Five-seveN is a great gun for it's intended purpose, but no manufacturer is going to sell you armor-piercing ammo. Armor-piercing ammo is perfectly legal to own, but the problem is manufacturers won't take the responsibility of selling it to civilians. That type of ammo uses materials that can be very hazardous. Without the AP ammo, the Five-seveN is effectively a $1000 pistol with terrible wound ballistics, and ammo that cost outrageous amounts of money.
Actually, I'm pretty sure Remington bought Bushmaster, not the other way around.
[QUOTE=Mr. Foster;39563830]-Argument for why my a gun on my wishlist is a stupid item to wish to own-[/QUOTE]
Please tell me what the ACR does so horribly wrong that the SCAR does so much better? Last I knew, it flung copper-plated lead downrange at a decent rate of fire, contained a short-stroke piston with two positions, with a non-reciprocating charging handle with fully ambi functionality. Aside from the knobs being weird on the left side, I've yet to see any major issues with it; and as a lefty, a factory-made left-handed bolt release is a better idea for me than a left-side only one.
Also, I shortened the Remington ACR to simply ACR, since that's the variant we were talking about. I guess comparing the two of the same rifle would be better, but I'm not following why you're trying to argue against what I wish I could have for the simple fact of saying 'look at what I have in my collection'.
[QUOTE=DaCommie1;39564092]Actually, I'm pretty sure Remington bought Bushmaster, not the other way around.[/QUOTE]
You are right, I had that completely backwards. It has been awhile since I've discussed the topic.
It seems to me, Foster and mastoner, that you're effectively arguing about one liking pancakes and the other liking crepes because they are slightly better for you (I don't know or care if it's true). And it seems rather silly... but in all honesty, FUCK YO CREPES! Pancake Master Race!
[QUOTE=mastoner20;39564305]Please tell me what the ACR does so horribly wrong that the SCAR does so much better? Last I knew, it flung copper-plated lead downrange at a decent rate of fire, contained a short-stroke piston with two positions, with a non-reciprocating charging handle with fully ambi functionality. Aside from the knobs being weird on the left side, I've yet to see any major issues with it; and as a lefty, a factory-made left-handed bolt release is a better idea for me than a left-side only one.
Also, I shortened the Remington ACR to simply ACR, since that's the variant we were talking about. I guess comparing the two of the same rifle would be better, but I'm not following why you're trying to argue against what I wish I could have for the simple fact of saying 'look at what I have in my collection'.[/QUOTE]
The simple fact that in reality, the Scar is a better platform. It does everything the ACR does without the reliability issues that have plagued (and still do plague) the ACR. Remington actually changed the piston system for a gas system because of reliability issues. Lets not forget the massive recall of the Bushmaster ACRs. I'm sure the ACR owners loved it when their semi-auto ACRs went full rock and roll on them. The Scar is fully ambidextrous as well, minus the bolt catch release. Even so, I've spoken to many Scar owners who are left handed, and they have no issue with the release not being ambi. Despite that though, I think it was a screw up on FN's part, but I'm sure there was a reason for it.
All of that aside, the Scar is simply better than the ACR. First and foremost, the ACR is incredibly front heavy. It's by far the most unbalanced weapon I have ever handled (Before it's asked, I've put more than 1000 rounds of ammunition through a Bushmaster ACR, I know what I am talking about.). This is not my opinion, this is fact, the ACR is unbalanced. There is also a 3lbs difference in weight between the ACR and the Scar (even the .308 variant is lighter than the ACR). For a weapon that under performs compared to the Scar, there is zero reason for it to weigh 3lbs more. This was one of the issues that Remington tried to resolve with their variant, but it required massive change, and the end result was still slightly heavier. Also, the Scar is no less durable than the ACR. It has also been proven time and time again that the Scar is more accurate than the ACR, and this comes down to design. The Scar's barrel has two connecting pressure points as opposed to the ACR's one. Lastly, the overall design of the Scar, despite it being much lighter, produces significantly less recoil than the ACR. I'm sorry, but FN designed a much better weapon.
As far as me arguing against what you want, if you read my previous post I said, "This is where our OPINIONS differ." Even if you could get what you wanted, that still doesn't change the fact that it would be a waste of money in MY eyes. I personally do not like spending money on something when I can have better for the same price.
Right, so as I also said; I never claimed the ACR was a better rifle. I claimed I wanted one. As the gun-nut I am, that is simply because I enjoy studying these types of things you bring up, which is why I want one. Also, on a minor note; the charging handle on the Scar is ambi; you tear down the front and switch sides, just like the ACR. The bolt catch-release is not. (I think I said the charging handle last page, which might be why I'm bringing that up).
And skullivan; Pancakes Master Race bros! :D Though I concur with the sentiment, I was just explaining why I want what I listed as my wishlist.
Thinking about getting a lighter .22 this weekend, I'm torn between the Marlin Model 60 / Papoose, the 10/22, and a Henry US Survival Rifle that's in a gun shop an hour away.
I think I'm developing a weird fetish for takedown rifles :downs:
I'd really like one of these:
[IMG]http://www.unfinishedman.com/wp-content/uploads/2012/08/nemesis-arms-vanquish02.jpg[/IMG]
I want a takedown nugget
[QUOTE=ButtsexV3;39565637]I want a takedown nugget[/QUOTE]
[img]http://img.ehowcdn.com/article-new/ds-photo/getty/article/97/19/87479449_XS.jpg[/img]
[img]http://i.imgur.com/qbnArTg.jpg[/img]
[img]http://i.imgur.com/w1frK9e.jpg[/img]
OH GOD SOMEONE PLEASE BUY ME THIS
seriously imagine it
it would require some serious mods to get it to work but it would be totally worth it
[QUOTE=mastoner20;39565435]Right, so as I also said; I never claimed the ACR was a better rifle. I claimed I wanted one. As the gun-nut I am, that is simply because I enjoy studying these types of things you bring up, which is why I want one. Also, on a minor note; the charging handle on the Scar is ambi; you tear down the front and switch sides, just like the ACR. The bolt catch-release is not. (I think I said the charging handle last page, which might be why I'm bringing that up).
And skullivan; Pancakes Master Race bros! :D Though I concur with the sentiment, I was just explaining why I want what I listed as my wishlist.[/QUOTE]
I meant the bolt catch release. I wasn't paying attention, my mistake.
You're exact words were: "Please tell me what the ACR does so horribly wrong that the SCAR does so much better?". This statement would indicate that you feel the ACR is on the same level as the Scar. Regardless though, I told you what the Scar did better, and I also mentioned again what MY OPINION was.
I started this back and fourth by stating some facts that you had wrong about the ACR. I also happened to give my opinion about the ACR, what I would do, and why. I'm simply stating my opinion like you did yours. You keep getting defensive about it when there is no need to. I know that you would still prefer to have the ACR, and that is fine if that is what you choose, but you keep trying to justify the ACR over the Scar. There is no justification for owning the ACR over the Scar, other than it being the gun that you want. My point: If it is what you want that's fine, but don't try to justify it based on functionality and because "it would be rare". No, it wouldn't be rare, considering everything done to a Remington can easily be done to a Bushmaster.
[QUOTE=Neat!;39565888]STOP ARGUING ABOUT STUPID SHIT[/QUOTE]
I'm not trying to argue. He just keeps coming back because my opinion is different.
[QUOTE=ButtsexV3;39565637]I want a takedown nugget[/QUOTE]
You can use both stock and barrel as club for beat in fascist and tsarist face!
[QUOTE=Neat!;39565888]STOP ARGUING ABOUT STUPID SHIT[/QUOTE]
Right, sorry. I misread his first response as saying my opinion was, in a matter of words, faulty; hense I got a bit defensive. I apologize. Moving on; those cds are really annoying, but mesmerizing... :/
[IMG]http://sphotos-a.xx.fbcdn.net/hphotos-ash3/p206x206/406140_3622379337947_1662387427_n.jpg[/IMG]
I bought a Lee Enfield 'Grenade Projector'
[QUOTE=Strider_07;39565525]Thinking about getting a lighter .22 this weekend, I'm torn between the Marlin Model 60 / Papoose, the 10/22, and a Henry US Survival Rifle that's in a gun shop an hour away.
I think I'm developing a weird fetish for takedown rifles :downs:
I'd really like one of these:
[IMG]http://www.unfinishedman.com/wp-content/uploads/2012/08/nemesis-arms-vanquish02.jpg[/IMG][/QUOTE]
OMG assassin gun!
I finally got a job, delivering Chinese food. I used to deliver pizza so I know what it's like but god I never delivered to such terrifying places before back home
Thank god for my friend in the glove box
[QUOTE=NuclearAnnhilation;39567440]I finally got a job, delivering Chinese food. I used to deliver pizza so I know what it's like but god I never delivered to such terrifying places before back home
Thank god for my friend in the glove box[/QUOTE]
How far you guys delivering? theres no good Chinese places where I live
I don't know if I'm allowed to drive to Georgia. Probably because I have no idea what my boss is saying ever. Shes so Chinese
But I'll air drop some off for you.
Oh and to make this gun related, I'm glad i have a job now so I can save for my M16A1 or 74
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