View Full Version : ar 15 caliber question

March 2, 2010, 10:34 PM
so i'm planning on building me an ar15..andd i am looking at the RRA items. i've noticed they make a 9mm and 40cal in hte ar style. sooo my question is as far as self defense,...which is better, 223, 9mm, or 40cal?

March 2, 2010, 10:38 PM
223 will go through 69 sheet rock walls before it stops, killing all your neighbors and their children. 9mm is for sissy Europeans. And 40 wishes it was a 45. :rolleyes:

It doesn't matter dude. Get the 223 if you're in doubt because the others require sometimes odd modifications, or use different parts that can make things more complicated for a newbie.

March 2, 2010, 10:54 PM
Go with a .223. For your first build I would definately go with a .223. You can always find parts for them cheap on the boards, and the ammo is readily available again.

March 2, 2010, 11:12 PM
I will be posting a question and just started building an AR-15, have two old parts guns and making one gun and then will start on the upper have plenty of parts and all the tools required. I have a sight question that I will be posting, back to your question.
I have a Beretta Storm in 45 ACP; it seems like a great carbine caliber with some 230 grain Golden Sabers loaded on the high side it is a great handling gun. I think the Storm is a great gun you can switch it from left handed to right, real easy. The weapon is light short and powerful, it has a retractable rail that you can extend and put a laser or light. I got all the extras with mine so have the three rails in the front. Not trying to sell the storm, an AR-15 in 40 or 9mm, would really be something. The complaint I have with the Storm, 45 large capacity mags are hard to find if at all. I see them for the 9mm, all the time. In the AR-15 a pistol caliber would be a real hammer, if a defense type gun inside of 25 yards would really get it done.

I will post pics of my gun as it comes along and will asked questions plenty of people know more then I on the AR-15, plan to draw on that help.

I’m thinking of a short defensive gun and mine will be in 223, using light varmint loads over penetration should not be an issue. It is a fast light gun and gives you range and long range accuracy over a pistol caliber. It really is a matter of choice, if my Storm had 30 round clips that would feed good, I would use it for a defensive carbine. However the 223 with V-Max 40- 60 grain would clearly be a man stopper!

I just tossed out some ideas; any of the calibers you named would work.

March 2, 2010, 11:26 PM
Actually, .223 will create less issues with overpenetration than the pistol calibers will. The reason is that the light, high velocity bullets have more of a tendency to fragment and/or tumble than the slower, heavier pistol bullets do. Of course if you're loading the gun with SS109 steel-core penetrators things might be different.

March 2, 2010, 11:29 PM
I would build a .223 first. Then add a drop in 22LR conversion for cheap plinking. You can build as many uppers as you want for the rifle and convert it back and forth as quickly as you can field strip it.

It's a great platform and has a lot of flexibility.

If you are going to build a dedicated 9mm, or 40 S&W then consider using the Lone Wolf lowers if you already have a Glock. It'll use GLOCK magazines.

I wouldn't have any problems using a .223 for home defense, provided its loaded with the "right" ammo.

March 3, 2010, 12:52 AM
My two cents...

.223 is twice the round as the pistol rounds. Cheap mags, readily available ammo, good longer range ballistics, platform is the same size as the pistol platform, .223/5.56 ammo optimized for the barrel, the round the AR was designed around.
I could go on an' on..

Save the pistol rounds for the pistols.

Now if there was a .44 mag/.454 casull 'ish version... ( and yup... I know about the various .458,.450,.50...they all use more expensive brass than .44mag brass.)

March 3, 2010, 11:11 AM
I go .223 for one main reason: if I'm going to have a rifle sized platform, I want it to shoot a rifle sized round. I've not read anything indicating pistol calibers perform better than the .223/5.56.

March 3, 2010, 11:21 AM
Among the other things already mentioned, .223 will have much flatter ballistics. Zero for 250m and you'll be within 2" +/- of your point of aim all the way out there.

The pistol calibers have rainbow like trajectories.

Personally, I can't see any advantage to a pistol caliber carbine over a light rifle round like .223. I sold mine to buy my first AR.

March 3, 2010, 12:09 PM
If pistol rounds are generally designed for optimal penetration from pistol length barrels isn't there a great chance they'll over penetrate at the usually higher velocities from a carbine length barrel?

March 3, 2010, 12:23 PM


March 3, 2010, 12:27 PM
I think that if you are going for an AR, go .223 but if you decide with a different caliber, checkout the Russian 5.45x39.
I do not really know the ballistics of the two but I would think that .223 and 5.45x39 ballistics is more similar than .223 and 9mm/.40.
Also, 5.45x39 (1080 rounds but corrosive steel cased). is half the price of .223.
5.45x39 non corrosive steel cased is $7.00 per 30 rounds.

I have a S&W 5.45x39 on top of a spike's tactical. Cleaning with warm water, windex, then WD 40 is not as bad as I thought.

March 3, 2010, 12:39 PM
Snaz, To me the key to your question is the self defense part of it. That being the issue, I'd think the 5.56 would have a major edge out of the 3 choices listed, in pretty much every situation.

Now if you want a pistol cal upper for the fun factor, dive right in! :)

My Oly 9mm AR is way too much fun, but it wouldn't be my "go-to" rifle. JMHO

March 3, 2010, 05:52 PM
It's really simple - a pistol is what you use fighting to get to your rifle. Old cliche, but ask yourself, What is the western world using to fight land battles with? It's the 5.56. The 9mm is holster decoration for times when you deal with unarmed people. A rifle caliber is used when the opponents are shooting back.

For self defense, the AR platform has most of the desired features. Be careful about caliber choices, right now there is a lot of foreign surplus on the market, but that doesn't make it the best long term choice. I tried that with .308 when NATO battle packs were 25c a round. No longer available, the dirty dogs were selling cheap because they were converting to 5.56.

Picking the caliber that works is far more important than a historically low price on surplus. Using it in something that works is equally important. The 6.5 and larger calibers are preferred for hunting and defense as they work well on 150 pound targets, two or four legged. Sometimes it's the only legal choice. Go big or go home.

Since a more appropriate choice in caliber is not any of the above, I'd recommend the 6.8 SPC II, other wise known as 6.8 x 43. It's the #1 alternate choice of AR shooters, legal for deer and hunting, flat shooting, effective to 500 yards, and more available in ammo choices, makers, barrels, uppers, and suppliers than any other alternate. While lots of whiners will blog on about ammo costs or shooting out beyond 400 yards, the reality is that for most of us, that doesn't happen. You can't get .30-30 Leverevolution for 25c a round, you can't get their caliber that cheap at Walmart, and most of us don't shoot that far. No reason to, no place to do it, no place to practice.

Think about it before rushing into a decision.

March 3, 2010, 06:02 PM
Somebody is making a cross-bow upper for an AR15 !!!:rolleyes:

March 3, 2010, 06:04 PM
which is better, .40 S&W, 9mm or .223?

March 3, 2010, 06:33 PM
New_Member_Name, if self defense is your primary concern, are you sure that you want to go with a rifle? A shotgun would give you more close-in stopping power for the same amount of bulk. Obviously if you WANT to build a rifle, that's a different story, but I'm just saying it's not the most obvious choice.

March 3, 2010, 07:26 PM
when i was in service, i thought we used the 7.62 for the m16, but i only **** it once, during basic.. would the 223 be better then 7.62?

March 4, 2010, 01:07 AM
My first AR was a 7.62x39 and I still have that rifle today. While I do have 223 ARs, they will go before my 7.62 will. Ammo is alot cheaper than 223, better defense round and you should see what it does to sage rats compared to 223. Dont get me wrong, the 223 is a decent round but it doesnt have the knock down power that my 7.62 does.

March 4, 2010, 01:19 AM
If you are an "old guy" and qualified with the M-14 or M-60 like we did, then you used 7.62X51 NATO (.308 sort of) ammo. If you used the M-16 it was 5.56 (.223 sort of).

Now you are talking about my favorite AR, the AR-10 is in 7.62X51 and yes it is one of my go-to rifles, along with my M1As. Much more knock-down power & effective range, talk about shooting thru walls!!:)

Double check what pilpens said. I discovered the 5.45X39 & S&W uppers several years back and couldn't be happier. For that size rd, its a great combo!

http://i106.photobucket.com/albums/m249/Allons11/th_ammo3005-1-1.jpg (http://i106.photobucket.com/albums/m249/Allons11/ammo3005-1-1.jpg)

March 4, 2010, 02:34 AM
Definitely .223 for your first AR-style weapon.

I also have the M&P 15-22 in 22LR which I use for practice/plinking. 22LR ammo is only like $25 for a brick of 500 rounds. Probably the cheapest and easiest to find ammo in the market. Just go down to your local wal-mart.
The 9mm would be fun, but ballistics is like half of the .223. I would completely stay away from 40S&W's. Although many law enforcement still use that caliber, very few civilians use that.

I have and always will only go with calibers that NATO and the UN have adopted in mass numbers. I don't want to end up with a chunk of paperweight that i can't find ammo for in 20-30 years.

For my next rifle, I'm thinking about getting a .308, either an AR10 or an M1A. Kind of a tough decision cuz the AR10 has many parts that are interchangeable with my existing AR15 system, but the M1A would be so much fun cuz of the totally different feel. The drawback of .308 is that ammo prices are double that of the .223.

March 4, 2010, 08:39 AM

.223 will go through 69 sheet rock walls before it stops, killing all your neighbors and their children. 9mm is for sissy Europeans. And 40 wishes it was a 45.

This is incorrect. There are a lot of publications out now that say 5.56/.223 will penetrate thru less walls than a 9mm. Several PD are switching from 9mm to .223 for this reason. They had to many 9mm rounds over penetrating. It was becoming a liability. .223/5.56 starts to yaw immediately after first impact. 9mm stays stable thru more layers of wall.

March 4, 2010, 09:50 AM
Thank you for setting me straight.