[Big19Ben]

Is there a difference between .223 rounds for bolt action or semi auto rifles. ie cartridge dimensions

[Retaks]

Nope. 223 is 223 wether its for a Remington 700, AR-15, or a Remington 760. The only difference could be overall length when using heavier bullets.

[HockaLouis]

Technically true, but, maybe not totally acurate: see .223 vs 5.56. Yeah, there's very possibly a difference. "Know your gun and its ammunition."

[Retaks]

Originally Posted by HockaLouis

Technically true, but, maybe not totally acurate: see .223 vs 5.56. Yeah, there's very possibly a difference. "Know your gun and its ammunition."

Yes there is a difference in 5.56 and 223 but he only asked about 223 so i assumed that all he was talking about.

[Vincine]

This is what I’ve learned (in the event you didn't know these things):

The bullet 'weight' (length really) matching the barrel twist rate is an important factor for accuracy. Even though the exterior cartridge dimensions are almost the same, heavy bullets (69 gr.) go in high twist rate barrels (1:8"), light bullets (55 gr.) go it slow twist rate (1:12") barrels.

Oh, and while they look almost exactly alike, even though you can fire a .223 round in a 5.56 semi auto, firing a ‘higher pressure’ 5.56 round in a .223 rifle fatigues the chamber and one shouldn’t do it.

But that's not what you asked.

[HockaLouis]

Vin;
Copy that to repost in a week. Perhaps you could write one in reverse for .308 vs. and 7.62 x 51.

[cakesterkiller]

can anybody actually tell me the difference between .223 and 5.56?

the only things I've seen are minor and irrelevant cause I've shot em both out of a bolt action chamber in .223 and an AR chambered in 5.56

and I have a tough time thinking that the pressure is that big of an issue cause I load my own and the loads are the exact same for both... the only difference I've seen is how far ya seat the bullet and is a difference of a few hundredths of an inch

[hmh]

The pressure for 5.56 is higher than that of a .223. Also I think the neck taper is slightly different. But the issue is the pressure.

[JTJ]

The 5.56x45 is loaded to a higher pressure than the 223 but that is in itself a big deal. A good quality bolt is proofed beyond that. The leade of the 223 chamber is shorter than the leade of the 5.56X45 chamber and that can be a big deal. The difference in the leade (distance the bullet travels before engaging the rifling) can cause an already over pressure load to go radically over pressure. Possibly 30k over under the wrong circumstances. Say a long heavy bullet seated into the rifling. This is where the danger lies. 223 hand loading data is for the 223 pressures. Max loads would still be under the pressure levels of the 5.56x45.

[Vincine]

I think I saw a SMALL difference in the radius angles of the neck when looking at the specs on the cartridge blue prints giving the 5.56 a longer throat. I think JTJ’s right. The bigger difference is in the rifle’s firing chamber, not the cartridge. RRA uses something called a ‘Wylde Chamber’ design which allows both to be shot without difference. I had been looking for a bolt action with a ‘Wylde Chamber’ to allow one to shoot either .223 or 5.56, but there doesn’t seem to be any.