Interesting New Quarterbore

Anyone else seen the new .25-45 Sharps cartridge from SRC Arms?

http://www.broadswordgroup.com/images/cor1.jpg http://www.broadswordgroup.com/images/cor2.jpg

It's basically the 223 case necked up to .257 caliber so it will reliably feed from any current .223/5.56 magazine. What's really interesting though is that this cartridge basically mimic's the old Savage 250-3000 ballistics as they claim to be pushing 87-grain bullets to 3,000fps. It's not something I think will take off in the mainstream bolt-gun circles, but I think it's a perfect cost-effective alternative to an AR-10 in .243 Win. as rather than spending $1,500-2,000 on said AR-10 you could just buy a $400-600 upper assembly for your standard AR-15. It could also be an interesting rebarrel option for a Savage Model 25.

I'd also like to see some velocity/trajectory data with the more popular 100gr .25cal hunting bullets (Nosler Partition or Ballistic Tip Hunting, Sierra GameKing, Swift Scirraco II, etc.).

If it's as good as the 6x45,should be a winner.

There were some guys on one of the AR forums that were wildcatting this round for a while now. They swore by it.

Should get close to the 257 Kimber I would think.

I wonder if the reamer is available yet........would be another good AR barrel for me to build.

Reamer is listed in SRC's webstore, but it's a bit pricey at $227.95! Redding and RCBS dies are available for $80-90.

That IS a bit pricey for just a necked up 223. Could just use a 257 neck/throat reamer with a standard 223 using a .257 bore sized bushing. If it weren't so high, I would be willing to pay them for their promotion of the cartridge anyway. But that's just too high for no more than it is.

I can see a bit of experimenting is going to take place on my part anyway. See if it'll match the 6x45 in an AR. My guess is it will and then some.

It's going to be similar to the TCU stuff back in the day of the Contender pistols except you're limited to 2.26 AOL.

The recoil should be super manageable. Maybe an alternative for a youth medium game bolt rifle other than a .243.

I thought about doing this one many times.

I like it. I would like it even more if it was Ackley improved. I have always wanted to Ackley the 7.62x39 case and neck it down to 257 and see what that would do. I think that would be a sweet coyote and deer cartridge.

The gain from improving the .223 case is minimal at best. IIRC it's only like 4-6% which isn't worth the added hassle in my book. Also, with the larger diameter bullet the shoulder area is so small there really isn't much there to improve anyway so the gains would likely be even less.

Just use the TCU version for a bolt action.........throated for whatever bullet you decide to shoot. Actually a good bolt version would be using the 204/222mag case for the little extra performance it would give without the added recoil.

AI'ing a case will vary a bit, but it is 10% in all of the 223 AI's that I have built. 69 gr Sierra HPBT in standard 223 is 3000 fps. Same bullet in an AI'd barrel is 3300 FPS. Of course, your mileage may vary.....especially when the SPEED does! :)