[JTJ]

Originally Posted by Vincine

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

Mossberg MVP. Chambered for the 5.56X45 and uses AR mags. I am looking very hard at getting one. I believe the CZ 527 Varmint is also chambered to take the 5.56. Remington makes a couple of rifles in the SPS series but they might not be bolts.

[Vincine]

Originally Posted by JTJ

Mossberg MVP. Chambered for the 5.56X45 and uses AR mags. I am looking very hard at getting one. I believe the CZ 527 Varmint is also chambered to take the 5.56. Remington makes a couple of rifles in the SPS series but they might not be bolts.

When I was researching this a while ago, the Mossberg MVP was stuck in the pipeline. Only a few had escaped for reviews, which were mixed. I think I'd love to be able to shoot either .223 or Lake City. Is the MVP actually on the shelves now? Let us know how it shoots if you get one.

There’s aren’t any 5.56 bolts on either the CZ or Remington sites that I could find.

[sniper762]

even though there is a slight "technical" difference between 5.56 mm and 223, no noticeable performance or danger to the shooter nor the rifle will or ever has been happenened by interchanging them.

[HockaLouis]

Originally Posted by 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.

Um, wouldn't you just buy one in 5.56, presuming you find one?

[JTJ]

Local lgs has an mvp with a 24" barrel. Nice looking gun. He is a little high on it though. I think I saw a couple available on line.

[Vincine]

Originally Posted by HockaLouis

Um, wouldn't you just buy one in 5.56, presuming you find one?

Perhaps they're not rare now. They were a year or so ago.

[billt]

The external case dimensions are identical. The only difference is in case thickness and in the freebore of the chamber itself.

5.56 MM



.223

[purehavoc]

I will say this My bolt action savage does not not do well with steel cased .223 ammo . It will shoot it fine but it expands and will not eject out of the bore without tapping on the bolt handle to get it out . it expands and does not contract like brass ammo ,
I dont shoot it thru it but I wanted to try it and se if it would work or not , the bore is just a little to tight for it

[Vincine]

Originally Posted by billt

The external case dimensions are identical. The only difference is in case thickness and in the freebore of the chamber itself.

5.56 MM



.223

Also from http://www.accurateshooter.com/cartridge-guides/223rem/

>There ARE differences between the .223 Remington as shot in civilian rifles and the 5.56×45 in military use. While the external cartridge dimensions are essentially the same, the .223 Remington is built to SAAMI specs, rated to 50,000 CUP max pressure, and normally has a shorter throat. The 5.56×45 is built to NATO specs, rated to 60,000 CUP max pressure, and has a longer throat, optimized to shoot long bullets.<

If look carefully at the shoulders you’ll see every so slight different specs for r1 and r2.

[billt]

Originally Posted by Vincine

Also from http://www.accurateshooter.com/cartridge-guides/223rem/

>There ARE differences between the .223 Remington as shot in civilian rifles and the 5.56×45 in military use. While the external cartridge dimensions are essentially the same, the .223 Remington is built to SAAMI specs, rated to 50,000 CUP max pressure, and normally has a shorter throat. The 5.56×45 is built to NATO specs, rated to 60,000 CUP max pressure, and has a longer throat, optimized to shoot long bullets.<

If look carefully at the shoulders you’ll see every so slight different specs for r1 and r2.

The problem with all of this is you can find .223 handloads to 62,000 in a lot of older manuals, and similar 5.56 MM loads that barely top out at 55,000.