Hi Folks, just sitting here cogitating and having a beer or 4, and got to thinking - I've looked at the possibility of rebarrelling my CZ 527 into 6x45 (ie 6mm/223), but then the thought occured to me - has anyone developed larger cals using the 223 case - ie 257, 6.5, 277, etc? Any idea what the results were? My first thought is that the CZ527 mag might be too short, but maybe I could NEED to buy a longer action!! Now there's a thought!!

I did warn you!

Yep,
Thompson Center and , I think it was Wes Ugalde (sp?),developed the TCU line of cartridges several years ago. They use the 223 case necked up and improved. I forget what degree the shoulder angle is. The 7TCU is very common in a Contender barrel and the 6TCU is faily easy to find. But the others, .25 & 6.5 are more difficult to locate.

Another option is a 5.6X50R case which is longer but otherwise similar to the 223. Not sure about the magazine, but I'll bet it would work for a single shot. This case will develope very near 22-250 velocity with much less powder. I have one in .22 and another in 6.5.

Rick

Well.......

I have a CZ 527 and I think you're going to run out of magazine length when you try to load 6mm bullets into a 527, as the MAX OAL is pretty short for the clip. If you were just looking to converting it into a small deer rifle, I'd keep it a 223 and work up some loads with the 60 gr. Nosler Partition or 70 gr. Speer bullet. I've shoot deer with both of these bullets and I don't think the animal would know if it were hit with a 22 caliber bullet or light 6mm.

One other option would be to convert the rifle to 6PPC, as the 527 is offered in the parent case 7.62x39.

How about the new 6.8 remington it is supposed to fit in an AR magazine.

It's been necked all the way up to .338", though there isn't much a shoulder left, and your mag would be short for such a critter. A 30 cal w/ 125 gr bullets might be interesting, but probably wouldn't have any advantage over a 7.62X39

Johnly,

What you're saying makes sense - now I've got the perfect excuse to go buy some bullets and play!

I'm still toying with my 35/303 Brit idea for a SMLE!

Thanks all, for your help.

Peter