Mike,
Check your PM's. Pay attention to that shoulder angle. I'll try and read the whole thing tonight. Maybe I can scan the artivle and email it to you.

knobmtn

You can find all the info you need in cartridges of the world. Kenny Jarret designed the cartridge, which also may be called the 6mm catbird. It is built on the 270 Winchester case, with a blownout case and a sharp shoulder.

Good Luck

Jerry

Out of curiosity, When did Jarret design and build the rifle. The reason I ask is back in 1968 I, along with Fred Banes, built a 6mm x .270 IMPROVED. The rifle is still bouncing mule deer back in the Grand Junction area. I used a case full of H4831 topped of with Fred's 115 grain " original, Original" bullet. With that combination there were no wounded deer. With contempory bullets of 105grains it turned into a terrible crippler. That rifle and a 22-250 tought me some saddly learned knowledge on proper bullet construction for high velocity cartridges. It really was a fun toy. roger

bartsche:

The article about the Catbird was in the March 1991 issue of Precision Shooting. It was written by Jarret. He didn't say just when he conceived the round but he did make it sound like it was a recent development at that point in time.

knobmtn

Several years ago I had 6mm/06s on switch barrel bench gun. I used 1 in 10 and 1 in 12 twists. I also had one of the barrels HV contour) early in its life rechambered to 6mm/284. The 6mm/06 was better.

I would imagine that the 6mm/270 and 6mm/270 Improved would have been common before the 25/06 became a factory round. The reason I say that is because I used 25/06 cases but if the 25/06 was not around as a factory item I would have gone 6mm/270 because 270 is better to neck down than the 30/06 and the reamer would have been set for the longer 270 case to save all the trimming, that is needed if 270s are necjed down for a 6mm/06 chamber.

Mike