I just finished my AR. I got the 5.56 upper so I know I can shoot either round. And I know 5.56 has more pressure, so I am assuming that the wear on the rifle would be less over time if I shoot .223. Would I extend the life of the chamber and the rifle overall if I stay with .223?

If you bought a quality barrel it's doubtful you'll every shoot it out regardless of the shell you're running.

Shoot whatever you want. You will have to go through tens of thousands of rounds to "wear" out a 223/556 barrel. AR's generally shoot better at 556 pressures.

Thanks, it's just that I have a lot of .223. So I guess I will switch to 5.56 after I burn through what I have now.

The only difference I've ever noticed, after thousands of rounds, was POI. However, I have that impact change between different bullet weights as well. In general, I prefer 62gr 5.56. I keep the 55gr .223 mostly for friends and family to plink around with.

Shoot what's cheapest and what works. I really doubt you ever "wear" it out. Heck, most troops don't wear one out

If using for hunting, might be better to shoot .223 because of bullet weights. All you're likely to find in 5.56 ammo is 55gr FMJ or green tip M855 (light armor piercing)

You may find this torture test to be interesting:

AR steel/brass ammo torture test

Good info in.

Thanks, interesting read!

Cheapest thing you can find. www.gunbot.net should be helpful.

What is the twist rate in your barrel? I wouldn't concern myself at all with wearing out the rifle. It will take THOUSANDS upon thousands of rounds before you even start to feel the affects of wear.

The twist rate is going to have a larger impact on the type of rounds you shoot and their accuracy.

I personally have always been a fan of 1/7 twist but most places tend to sell 1/9. The 1/7 twist allows me to shoot a wider variety of heavier match grade loads. That said, I avoid shooting anything below 55gr as the rate of twist is such that lighter rounds may even rip apart as soon as they leave your barrel.

Food for thought.

Thanks for all the info. RLTW27, 1-8 twist. I will probably use Brass case 55gr FMJ. Just using it for plinking and fun, not for a hunting rifle, except the occasional hog.

I expect people may quote some science that proves that I'm wrong, but I like my 1:8 barrels in 16" AR's - strictly based on my own experience.

While I generally do not shoot my AR's past 150-200 yds, I do like how they shoot with a wide variety of bullets between 45gr and 75gr. Without running tests, I would say that mine give me the tightest groups with 62/75gr.

But then my guns can also out-shoot my skills with the shorter, faster 45gr varmint rounds :-)

Marc

I run the cheap Tula $#!+ by the thousands in my 6920. I would buy brass case if tula wasn't so cheap. It allows me to get out and shoot more.

I've put thousands of rounds through one of my rifles I use for 3-gun matches. To date I've only experienced one issue that stopped me from shooting and it was the result of a cracked bolt. Cracked from the bolt face to the cam-pin on one side. It didn't go all the way through (thankfully) but did fracture enough to notice something was wrong and upon inspection stop me from completing the stage.

With that being said I'd also agree with what Rifleman1775 said about the .223 hunting rounds vs. surplus 5.56 rounds and the different selection availability for the two. I'm running 55 grain FMJ for all my short range, paper punching competition stuff and have used 60, 62 and 69 grain rounds for my longer stuff. I'm currently using 60's since I've got a couple thousand rounds loaded up and once those are gone I'll be using 69's.