Ok, here's the deal. I got a co-worker hooked on building an AR. I told him I had gotten a DoubleStar lower and decided to go with thier kits to complete my 16"er. He wants to save a little bit of money and go with a Model 1 Sales kit and a DPMS lower. I have no arguements on the lower. The kit, however, is another issue. The problem is this. Are the kits  Model 1 sells a 5.56 NATO upper or are they .223? Not sure if it made a difference. I believe the J&T are 5.56 NATOs and have never had a problem. So, Model 1 are 5.56 or do they even know.LOL!

Ken
I will have him check out this forum to get his answer. I think he should go with a Bushy or RRA.

Pretty sure they're 5.56.

Says so in their ad in Shotgun News.

WIZZO

Quoted: Ok, here's the deal. I got a co-worker hooked on building an AR. I told him I had gotten a DoubleStar lower and decided to go with thier kits to complete my 16"er. He wants to save a little bit of money and go with a Model 1 Sales kit and a DPMS lower. I have no arguements on the lower. The kit, however, is another issue. The problem is this. Are the kits  Model 1 sells a 5.56 NATO upper or are they .223? Not sure if it made a difference. I believe the J&T are 5.56 NATOs and have never had a problem. So, Model 1 are 5.56 or do they even know.LOL! Ken I will have him check out this forum to get his answer. I think he should go with a Bushy or RRA.

I believe Model 1 has posted on this forum before that their chamber's are 5.56.  The differences aren't that major and have been covered around here before.  Lots of people have shot surplus 5.56 ammo in .223 chambered rifles without problem.  Shooting .223 Rem ammo in a 5.56 should never be a problem.  It is theoretically possible to get a 5.56 bullet or case mouth jammed in a .223 chamber but I personally don't think it is very likely unless you have a very tight .223 chamber (unlikely in a semi-auto as they tend to be a little generous to be condusive to reliable and smooth functioning) and 5.56mm bullets or cases that are pushing the tolerances the other direction.  Since Model 1's ads state "5.56mm NATO or .223 Remington", one would assume you can safely shoot either, and thus their chambers are probably 5.56 dimensioned.

If you are really worried about the kit, Model 1 is usually only $10 to $20 cheaper than M&A, J&T or Del-Ton.

Model 1 kits allow you to choose  5.56 or 223 chamber so it's what you request.

Well, I've had local gunsmiths tell me that there is no difference between the two.  A .223 is actually .222, but they needed a different designation for it, so they called it a .223.  The only difference, as far as I know, is a 5.56 has about a grain more power behind it.  That's it.

On another note...how do you like the Double Star lower.  I'm getting one this week.  How much was it?

-Jbot

Quoted: Well, I've had local gunsmiths tell me that there is no difference between the two.  A .223 is actually .222, but they needed a different designation for it, so they called it a .223.  The only difference, as far as I know, is a 5.56 has about a grain more power behind it.  That's it. On another note...how do you like the Double Star lower.  I'm getting one this week.  How much was it? -Jbot

Not even close,  

The 223 is longer than the 222, and the 5.56 works to higher pressures than the 223 (read has a different throat section to deal with the higher pressures).  Keep listening to smith, and sooner or later I'm sure he will make you a hell of a deal on the his 221 firball ammo he has sitting around since surely it will fit into the rifle as well as the 222 he stated will.

LOL Your local gunsmith should be drug out back and shot for some dumb ass statement like that

The DoubleStar lower is great! I was at a local gunshow and I happen to have a gun permit. I saw a J&T booth setup and asked them for a lower. They did'nt have one but pointed me to a sister company that had one left. Needless to say, I hurried to get the last one. It was a display model, but so what. I did'nt care. I got it for $109 total. Everything fit into place without a hitch. I asked them for thier address or website so I could get an upper assembly to complete it. It has always functioned flawess with every ammo (even Wolf...cringe).Thats why I tried to get the guy to spend a little more for better quality.To each his own I guess.

Ken

Quoted: Model 1 kits allow you to choose  5.56 or 223 chamber so it's what you request.

Yep.  Read the website, you can choose either.

There are small differences between 5.56 and .223, but they can add up to be huge.

Quoted: Quoted: Well, I've had local gunsmiths tell me that there is no difference between the two.  A .223 is actually .222, but they needed a different designation for it, so they called it a .223.  The only difference, as far as I know, is a 5.56 has about a grain more power behind it.  That's it. On another note...how do you like the Double Star lower.  I'm getting one this week.  How much was it? -Jbot Not even close,   The 223 is longer than the 222, and the 5.56 works to higher pressures than the 223 (read has a different throat section to deal with the higher pressures).  Keep listening to smith, and sooner or later I'm sure he will make you a hell of a deal on the his 221 firball ammo he has sitting around since surely it will fit into the rifle as well as the 222 he stated will.

Huh...I knew there had to be a difference, but after hearing this local dealer, I figured he'd know better than me.

Anyhow, cool to hear about the Double Star.  Can't wait to get mine...

-Jbot

Here's a good article on the subject...ah, wikipedia...

http://en.wikipedia.org/wiki/5.56_mm_caliber

-Jbot

And boiling it all down to a simple description, the 5.56 chamber CAN be up to 0.004" longer than the 223, but it's not gauranted to be.
The 5.56 throat is about 0.0025" larger in diameter than the 223 throat, so the bullet is sloppy loose in there, good for reliability, bad for accuracy.
Lastly, the 5.56 ammo spec is several thousand PSI higher.
In modern actions such as we play with, the roughly 5% pressure increase is not an issue.

Randall Rausch
www.ar15barrels.com

think both can be had in either 5.56 or .223 but maybe not jt