The Firearm thread: Engineering artistry of wood, polymer and steel.

[Ducimus]

Since I'm not the only person on the forum who owns guns, and the topic comes up now and then, usually in the form of derailments, and since it was suggested to start a thread of this type, I took the initiative.

This is not intended for political discussion.
If you really want beat on a dead horse, there are plenty of politically charged threads already in existence. Please use the search function, and find an appropriate thread for expressing your views.

This thread is intended for "shop talk", education, or training, and to keep all non political discussion about guns in one place.

Have safety concerns? Post it here.
Training concerns? Post that here as well.
Looking for advice on a firearm purchase? Go ahead and post that here.
Doing a little novice gunsmithing? post about it here.
Interested in owning a certain firearm? Daydream about it here.
Want to brag about whatever it is you own or post pictures of them? Brag about them here.
Have a great day at the Range? Tell us about it here.

[August]

Apparently there's a difference between .223 and 5.56. Firing the former in a weapon chambered for the latter is safe but the other way around may cause bad things to happen.

As The Arms Guide (<-- Link) puts it:

The most important difference between .223 and 5.56 chambers is the length of the throat (or leade) for each chamber. More specifically, the leade is located at the mouth of the barrel before the rifling occurs. Comparing the NATO and SAAMI regulations, the leade for 5.56 chambers is nearly twice as long as that of a .223 chamber (.162in to .085in, respectively). If a 5.56 round contacts the barrel rifling too early, it can cause pressure spikes (leading to malfunction, and potentially damage) in the chamber. This explains why it is safe to fire .223 through a 5.56 chamber, but not recommended to fire 5.56 through a .223 chamber.

So, my question is should I have the throat of my 223 AR lengthened at great expense, aggravation and possible risk involved with finding a Gun Smith experienced and equipped to do this properly and hoping he doesn't screw it up.

OR

Wait for prices to come down some more and buy a whole new upper for my AR that is already chambered for 5.56? (presently about $500-$1K).

[Red October1984]

Originally Posted by August

So, my question is should I have the throat of my 223 AR lengthened at great expense, aggravation and possible risk involved with finding a Gun Smith experienced and equipped to do this properly and hoping he doesn't screw it up.

OR

Wait for prices to come down some more and buy a whole new upper for my AR that is already chambered for 5.56? (presently about $500-$1K).

Most AR's should be chambered for 5.56...

What kind of AR do you have? Yes there is a difference...but with AR's you never know. There are some AR's that are officially chambered .223 but are really rated for 5.56

@Ducimus Thank you for starting this up. It's good that we have a thread for this now so we can avoid major political debates.


----

I still haven't been out to the range to sight in my Savage Axis .223 from Christmas....one of these days I will.

Come to think of it...I haven't shot in a long time. I don't mean like little .22s...I do that all the time...

Last time I shot anything bigger was Thanksgiving. I went out with some family and an SKS, .40 Compact (Manufacturer unknown. I didn't look) and an old .22 bolt action.

My uncle told me that if I hit the 100 yard target with that .22 he'd be impressed. So guess who went and did just that? No scope on a windy day... Took me a few shots but I got it.

Shooting is a great hobby.

[August]

Originally Posted by Red October1984

What kind of AR do you have?

Colt Sporter II 1988 vintage. I've already checked that out. Mine is one of the ones that has the short leade.

[Red October1984]

Originally Posted by August

Colt Sporter II 1988 vintage. I've already checked that out. Mine is one of the ones that has the short leade.

I think it comes down to a matter of personal preference.

From what I understand, AR's are chambered for 5.56 and some of them get marked for .223

I'm by far no expert. If you check with a gunsmith, he'll just tell you that 5.56 can't be fired from it and point you to the internet where there are arguments that go both ways. I've read very convincing arguments backed up by facts that say you're good and that there have never been guns to blow up. There are arguments that say you will have an explosion because of the higher pressure that the 5.56 shoots at...

There are also tons of bogus arguments about casing size, size of Milspec chambers vs Civilian chambers...nose to primer length...bullet size, etc.

It's up to you really.


----

On another note, I saw this one time and I have to share it here

Mosin Nagant vs. AK-47 vs. AR-15

[Stealhead]

Originally Posted by Red October1984

Most AR's should be chambered for 5.56...

What kind of AR do you have? Yes there is a difference...but with AR's you never know. There are some AR's that are officially chambered .223 but are really rated for 5.56

When you are talking about an AR-15 it depends on when it was produced from the 70's into the early 90's they usually where chambered for .223.After the end of the Cold War there was a ton of mil spec 5.56mm laying and the many makers of AR-15 and clones decided that they should produce the rifles in 5.56mm instead.The date of manufacture makes a difference but the biggest thing is what is stamped on the weapon you should use that caliber even if there is a very very similar caliber.

I would not fire 5.56x45mm out of an AR-15 that has a .223 chamber even it does not explode which is likely a old gun shooting wives tall the two cartridges are different anyone that says other wise does not know what they are talking about.


The 5.56mm cartridge has a higher pressure higher than the design tolerances of the .223 chamber now any fire arm is going to be able to handle a higher pressure to some degree so would a .223 chamber explode from a 5.56mm cartridge I very highly doubt it.Will the higher pressure cause damage over time? Yes. How much it would depend greatly on many factors.Will the higher pressure cause screwy problems like blowing out primers? Yes


I would wait on the new upper better route to go any day of the week.You know for certain the upper is designed to a certain spec.Also I think that old lowers and new uppers are cool it is a new gun and an old gun all at the time.

I like the page about the Mosin-Nagant they got a little carried away though it does have a safety and a magazine.

[Ducimus]

Originally Posted by August

So, my question is should I have the throat of my 223 AR lengthened at great expense, aggravation and possible risk involved with finding a Gun Smith experienced and equipped to do this properly and hoping he doesn't screw it up.

OR

Wait for prices to come down some more and buy a whole new upper for my AR that is already chambered for 5.56? (presently about $500-$1K).

I'd wait for the prices to come down. I just did a quick image search on the Colt Sporter II 1988. Does your rifle have the fixed A2 carrying handle? If so, i'd definitely wait for the prices to come down, or for a screaming deal, and then get a 5.56 chambered flat top upper reciever. That way, you open yourself up for accessory options. A red dot scope with a magpul mbus cowitness for example.

Also, you keep your rifles original reciever intact and unaltered/undamaged, which gives you the option to revert the rifle back to it's original form.

[August]

Originally Posted by Ducimus

I'd wait for the prices to come down. I just did a quick image search on the Colt Sporter II 1988. Does your rifle have the fixed A2 carrying handle? If so, i'd definitely wait for the prices to come down, or for a screaming deal, and then get a 5.56 chambered flat top upper receiver. That way, you open yourself up for accessory options. A red dot scope with a magpul mbus cowitness for example.

Also, you keep your rifles original reciever intact and unaltered/undamaged, which gives you the option to revert the rifle back to it's original form.

Yes my rifle is the old fixed handle type. See below.

My thought was to buy a complete upper including bolt carrier group (though that is a quick enough swap), front sight post and hand guards and bring one or the other to the range depending on what type of ammo I have.

[Ducimus]

Originally Posted by August

My thought was to buy a complete upper including bolt carrier group (though that is a quick enough swap), front sight post and hand guards and bring one or the other to the range depending on what type of ammo I have.

Well, if you get a 5.56 NATO chambered upper, its really all you need. Headspace aside (haven't done my homework on .223 and 556 headspacing, I'm assuming their same), you have the chamber pressure rating to feed it 5.56 or .223 at that point. My wife can feed either one through her rifle without any issues whatsoever.

EDIT: I think the only major difference is more brass expansion with .223, the cases are slightly thinner then 5.56, and NATO chambers tend to be a bit looser to allow for dirt, and debris.

[August]

Originally Posted by Ducimus

Well, if you get a 5.56 NATO chambered upper, its really all you need. Headspace aside (haven't done my homework on .223 and 556 headspacing, I'm assuming their same), you have the chamber pressure rating to feed it 5.56 or .223 at that point. My wife can feed either one through her rifle without any issues whatsoever.

EDIT: I think the only major difference is more brass expansion with .223, the cases are slightly thinner then 5.56, and NATO chambers tend to be a bit looser to allow for dirt, and debris.

Correct. The idea is to be able to swap between them quickly. Good idea on the flat top rail too.

[d@rk51d3]

Originally Posted by Ducimus

You know, I have to wonder, just how important is the 3.5 " shell ? I would look into the value of a 3" vs a 3.5" more. .

Seems that 3.5 shines at steel shot and long range. Although newer HV 3" loads seem to have pretty much caught up.

[d@rk51d3]

Originally Posted by Red October1984

Very pretty rifle. I wouldn't mind owning one of those but .303 is SO expensive here...I see it on the shelf for 34$ per box of 20.

I'd own it and never use it.

Cast and Reload.

[Harvs]

This is the same rifle with ATI synthetics.

[Harvs]

And again, same rifle after airbrushing, I am about to change the cam pattern to match my surroundings a bit more.

[Jeff-Groves]

Now I like that setup!
What Bipod and Scope setup do you have?