Basic Questions about the AR 15

[ebausch]

The AR consist of two halves the upper and the lower. The lower receiver is the registered part and is the only part you can not buy mail order. Everything attaches to this receiver and the lower is considered that receiver the trigger group, pistol grip and butt stock.

The upper is normally attached to the lower with 2 pins (Colt uses a screw and a pin) It includes the upper receiver that holds the bolt/bolt carrier and barrel. You can have multiple uppers like a 20 inch barrel with a scope and a 16 inch iron sighted upper and attach them to the same lower or with a mag block you can even have a 9mm upper.

An AR meets all your requirements except for the low cost.

As far as a ban goes there is no way to know how a future ban will be worded making it impossible to say what will be banned. The 1994 crime bill ban expired in 2004 so folding stocks, bayonet lugs and all the other evil features are perfectly legal...for now.

 

[IndyFan]

Thanks, ebausch. So most uppers and lowers are compatible from different manufacturers? Since Colt has a screw and a pin, does that limit you to only mating Colt uppers and lowers?

 

[Gregory]

All depends on the model of Colt, All of Colt's current LE line (100% legal to own in ban free states) are small pin front and rear aka Mil-spec.

Now Colts trigger pins are still larger dia, but that does not matter as any trigger worth having also makes the larger dia.

Even if you had a large/small hole upper and a small/large hole lower offset pins are sold.

 

[CITYSLICKER]

Originally Posted By: Gregory
All depends on the model of Colt, All of Colt's current LE line (100% legal to own in ban free states) are small pin front and rear aka Mil-spec.

Now Colts trigger pins are still larger dia, but that does not matter as any trigger worth having also makes the larger dia.

Even if you had a large/small hole upper and a small/large hole lower offset pins are sold.



And yes different MFG will fit each other , in fact it's entirely possible to have one lower and several different uppers by different manufacturers in different calibers even ( some of the alternate calibers will require different mags ) 6.8 SPC , 7.62 x 39 , even 50 Beowulf are available , also 22LR , 45ACP , 9MM ...

As mentioned above there is currently no ban on anything other than the regular NFA rules ( 16" + barrel , no full auto , no suppressor , etc. )

 

[chevrofreak]

Originally Posted By: IndyFan
What do you have and what do you like, Chevrofreak?


I have an AK, but if I were to pick something that wasn't an AK, it would have a gas piston. Something like a SIG 556, Robinson Armament XCR or the Bushmaster ACR (when available). Maybe even a POF or LWRC piston driven AR.

Gas pistons are cleaner, they run cooler, and they're more reliable.

Accuracy isn't everything. I'll take the hit in accuracy for a gun that is as near 100% reliable as possible. That's why I like Glock's and AK's.

 

[chevrofreak]

Originally Posted By: GMBoy
While neither the M16/AR15 or AK/SKS guns can be considered "hi-power" by any means - I agree with you thst the AR is the more accurate rifle by far. But the AK shoots a more potent round and will work in the dirt. Best thing is to just buy one of each


The AK and SKS have a bad reputation for being inaccurate, because people feed them cheap ammo. I have some Wolf hollowpoints and if you shake them you can hear the lead core rattling around inside the jacket in about 1/3 of them. The powder charges are also inconsistent.

It also doesn't help that the triggers tend to be pretty poor. You can easily fix this, though. Most AK triggers have a lot of overtravel, which causes quite a bit of inaccuracy itself. I've modified an AK trigger to have an extremely short, smooth, light pull. It rivaled any AR trigger I've ever felt.

The biggest downfall for accuracy with the AK and SKS is the sights. Put a red dot sight on them using a good mount and that problem disappears. Feed it good ammo, and they will be a lot closer in accuracy to an M4 than most people realize.

 

[Gregory]

Never seen anyone win a USPSA rifle match using an AK. In my are these are usally 200 yards and under. 3 hand reloads and [censored] poor ergos of the rifle make it a bad choice.

All a piston design does is put the carbon some place else. Every 300 rounds I must clean the piston on my M1ANM or accuracy will degrade. With my AR I've gone twice that amount and no loss in accuracy.

 

[JosephH1]

As previously stated, you should be safe building with components from any of the major players. My home built AR is a Bushy lower, upgraded trigger group and Armalite upper. Plenty accurate and 1000 round reliable with out cleaning. Be sure you get a chrome lined chamber and barrel and use decent ammo. Many reliability problems stopped when the military reformulated the gunpowder (in the 60's), chromed the chamber, added the forward assist and issued cleaning kits. I am so happy with my ARs that they are my "s##t hits the fan" weapon.
One last thing, in this political climate I would only buy a long gun or AR lower (legally) from a private citizen. The BATF is not supposed to keep purchase info from the yellow form, but they were caught doing just that in the 90's. I just don't trust big brother. Again, absolutely make your purchase legally, but I would avoid the BATF form by buying from a non-dealer.

 

[SinisterK9]

Any reputable brand ought to run just fine for you. I prefer Rock River Arms myself. Both civilian PD's I've worked with use them with no problems to speak of. Being in the military, I've carried a Colt for the past 9+ years. M16A2 until about 2002, since then an M4. I've never had problems with either. Take care of the gun, and the gun will take care of you. That's why we are constantly cleaning our guns. Stateside we clean our guns at least once per month whether we fire them or not. In desert environments we clean daily. Most failures of the weapon can be attributed to owner/operator error, or neglect.

 

[chevrofreak]

Originally Posted By: Gregory
All a piston design does is put the carbon some place else. Every 300 rounds I must clean the piston on my M1ANM or accuracy will degrade. With my AR I've gone twice that amount and no loss in accuracy.


Putting the carbon somewhere other than the action is a good thing.

An AK can go its whole life without the gas tube being cleaned, but that is because of the tube design. Something most people don't realize is that the AK is actually a short stroke piston. The cylinder the piston rides in is in the gas block, the gas tube is just there for protection.

 

[y2k345]

If you get an AR15 I`d reccomend getting one with 20inch barrel and flatop receiver.

 

[Tempest]

Quote:
Something most people don't realize is that the AK is actually a short stroke piston. The cylinder the piston rides in is in the gas block, the gas tube is just there for protection.

I'm not sure how a piston that moves the entire cycle can be considered a short stroke piston?? Even if the gas is vented out of the tube before it reaches the bottom of it's cycle.

 

[chevrofreak]

I found this information one day while surfing the web.

Yes, it contradicts the expert information found on wikipedia.

Gas systems
There are four principal types of gas operation: short-stroke, long-stroke, gas trap, and direct impingement.

A short-stroke gas system is defined as one which uses high pressure gas from the middle portion of the barrel that impinges on the piston head for a short period of time before excess gas is either cut-off (M14) or vented (AK-47) or the piston head reaches a stop (M1 Carbine). The distance the piston travels under pressure is generally less than its diameter.[2] The piston may or may not be attached to the bolt carrier. This is the most common type of gas operation.

A long-stroke gas system is generally defined as one which the stroke of the piston under pressure is greater than its diameter.[3] Because of the greater dwell time, gas must be ported from the barrel very near the muzzle of the weapon as in the M1 Garand. This relatively lower pressure gas acts over a longer period of time to impart the same amount of energy to the operating system. Because the operating parts are longer, they are necessarily heavier and this system is not used in modern weapons.

A gas trap system is similar to long-stroke operation, however gas is 'trapped' after leaving the muzzle. The "Bang" rifle and early "gas trap Garand" rifles use this system. The German MG-42 machinegun and other recoil operated weapons use this energy in combination with recoil energy for more reliable and energetic operation of the weapon. The gas trap system is also obsolete.

The direct impingement method of operation vents gas through a tube to the working parts of a rifle where they directly impinge on either the bolt itself as in the M16 rifle, or the bolt carrier proper.

Misconceptions
The terms short-stroke and long-stroke are often confused by both laymen and experts. The stroke is that portion of time when combustion gases contact the piston head prior to venting. It is not the total length the piston head might travel during the cycling of the action. The commonly reported misconception is that a piston being rigidly affixed to the bolt carrier is what constitutes a long-stroke system. The AK-47 is commonly referred to as a long-stroke action while the Armalite AR-18 is often used as an example of a short-stroke system. In fact, the stroke is virtually the same and the gas port is in nearly the same location along the barrel for both rifles.

 

[Tempest]

From a quick search, there appears to be much debate on this and no consensus. Luckily we have some engineers on this site that might provide some insight.

 

[chevrofreak]

It stands to reason that if a piston isn't inside of a cylinder, it is no longer a piston but just a nice round piece of metal.

So, if the piston of the AK-47 exits the cylinder (the gas block) after only about 1/2" of travel, that would make it a short stroke.

 

[Tempest]

Originally Posted By: chevrofreak

So, if the piston of the AK-47 exits the cylinder (the gas block) after only about 1/2" of travel, that would make it a short stroke.

All gas operated guns that I am aware of have a vent in the gas tube. This would make all gas operated guns short stroke by your definition.

To me, the fact that the piston travels the full stroke of the carrier makes it a long stroke. This IS different from many gas guns where the piston moves a fraction of the amount of the carrier or bolt.

Again, I'd like to get the input of the engineers here on their opinions.

 

[Gregory]

This almost as good as FN FAL vs M14

 

[chevrofreak]

Originally Posted By: Tempest
All gas operated guns that I am aware of have a vent in the gas tube. This would make all gas operated guns short stroke by your definition.


That's because most guns ARE short stroke.

But it isn't that they have a vent, it's where the vent is. If the piston travels a distance greater than its diameter while under pressure, then it's long stroke.

Just like undersquare and oversquare when talking about engine piston travel. http://en.wikipedia.org/wiki/Stroke_ratio#Bore.2Fstroke_ratio

 

[IndyFan]

Well, I did it. I picked up a used Bushmaster AR15 with a 20" barrel and a removable handle, so I can use either the standard sights or mount some kind of optical sight. I really wasn't sure which way I'd want to go, so I thought this let me maintain my indecision and still get a rifle.

I don't know how old it is, but it is in pristine condition, without any kind of a scratch anywhere on it. Everything looks new, including the inside of the chamber and all of the mechanisms. I could not tell it from a brand new one that I looked at along side of it. I was told it only had one 20 round box of ammo shot through it, and then it sat in a gun safe ever since. You never know about those things, but visually, it was in new condition, so what the heck.

I appreciate the discussion and opinions. Now the fun part is going to be learning about this thing, firing it at the range, and then adding some accessories or mods. A cool Bushnell holographic sight caught my eye at the gun store, so I might have to check that out. It is just like the Eotech, but without the steel hoop, and about half the price.

I'll let you know how it goes when I get the chance to shoot it. Hopefully, that will be within the next couple of weeks.

One more question--What do you think of Silver Bear ammo? A couple of friends told me they have shot thousands of rounds of it and had no problems at all. I bought a box of 500 for 159 bucks, just to get started.

I'm interested to hear opinions and prices for different kinds of ammo.

Thanks!

 

[Samilcar]

Congrats!

Sounds like you got the same rifle as mine, except for the removable handle. Silver Bear ammo is fine russian ammo. I would stay away from the older russian Wolf ammo. It's lacquer coated and there have been a few instances of this lacquer "gluing" itself into hot AR chambers if the cartridge is sitting in the chamber for awhile. The newer polymer coated Wolf ammo doesn't have this problem.

Enjoy your rifle!