Not your typical 5.56 vs .223 thread...

[Hammer059]

I'm already aware of the pressure differences between 5.56 and .223. My question is: Over an extended time, will regularly shooting the higher pressured 5.56 be harder on the rifle than .223?

My gut tells me no, but it would make sense when you consider that this applies to other calibers and platforms. Shooting .357mag out of your revolver on a regular basis is going to be harder on your gun than .38spl over the long run. Shooting Buffalo Bore .44mag on a regular basis out of your model 629 is going to do the same on a regular basis for extended time.

So what gives? Will shooting the "lower pressured" .223 be any easier on a specific part or overall functioning of the rifle in the long term?

I just bought 1,000 rounds of 5.56, so I'm hoping the answer is no...

 

[jmr40]

The specs allow for slightly higher max loads in 5.56. Virtually no one ever loads right to the max. You'd be unlikely to find a factory 5.56 load that was actually loaded any hotter than 223.

There is a significant difference between 38 and 44 Special and 357 and 44 mag. The difference between 223 and 5.56 is pretty small in comparison.

 

[Hammer059]

Thanks jmr40. I kinda figured, but I wanted to be sure.

 

[Hardtarget]

I don't know how others look at it but I've shot only a small amount of factory ammo in my AR. When I reload I stay a bit under max. I'm just working to get function and accuracy.

If the need was more "critical" than putting holes in paper I might tend to load a bit hotter.

I understand your point. No need to beat up your rifle more than you have to. Shooting the gun puts some stress on it but thats what it was made for!

Go shoot! Have fun!

Mark

 

[Hammer059]

Mark, hopefully I'll be hopping on the reloading wagon soon enough!

 

[tark]

I think you will shoot out several barrels before you wear out a part from a steady diet of 5.56mm. Google up SAAMI, rifle cartridge pressures, or something similar. I don't think there is much difference between the two.

 

[Liberty1776]

1,000 rounds is not enough to make a difference.

 

[rcmodel]

One might do well to remember the M-16 / AR-15 was designed from the very beginning as a 5.56 military weapon, capable of full-auto fire.

They didn't design it, and improve it constantly to wear out in 1,000 rounds.

rc

 

[matrem]

Not preaching this as gospel, but when shot in a rifle with a 5.56 chamber?

Just not convinced it "hits" the rifle any harder than a .223 round does to a rifle with the rifling cut to .223 specifications.

 

[Hammer059]

I didn't ask if it would wear out in 1,000 rounds. Obviously that isn't the case. The reason I mentioned purchasing the ammo is because that's what made me think of my question in the original post. I'm talking long term, and as often as I shoot, 1k rounds is nowhere close to long term usage for me.

 

[Stumper]

Revolver wear is quite different from that of a semi-auto rifle. Higher pressure isn't moving a magnum revolver toward a sudden catastrophic failure, rather, higher recoil levels are slamming the cylinder back and forth, gradually peening small tolerances into larger ones and stressing small parts such as the hand. In an AR the rotating bolt is locked at peak pressure then opens at MUCH lower pressure and recoils back into the buffer. The differences in port pressure do not necessarily correlate to the differences in breech pressure.( a higher pressure load could have lower gas port pressure due to a different pressure curve) It is entirely POSSIBLE that a max spec load may cause slightly more violent cycling but buffer springs are replacable even if more strain/wear did occur. Likewise, in the rare occurrence of a cracked bolt lug in an AR the rifle usually remains undamaged and the bolt is replaceable.-And even many thousands of max loads don't usually crack a lug.
In other words -don't even worry about this stuff!

 

[Hammer059]

Thanks, Stumper! You explained it very well