Originally Posted by Crusty Buck
Trickymissfit, Wow those are harsh words for the beloved Win. 243
Do you think they got the Weight/BC/Throat Thing straightened out with the .264? What I'm hearing you say here is that there is a real balancing act with the .243; heavy vs light weight bullets, and that the BC is not as important as the throat demensions? I shoot 30's, 308 Win and 300 Win Mag. They seem to shoot 150's and 165's with ease and accuracy. I have heard the 180's will really shine in the 300. Is there something inherrant to this success? I am planning on rebarrelling the 308 to a .260 or 7mm-08 when the time comes. Any thoughts here?
No the B/C is imprtant, but there some other factors that have to be taken into thought. With the short .243 neck you are often pushing the bullet back into the shoulder reducing case volume (and short throat). Now with a long throated .243 you at least have a way to cope with the long bullets in that the troat is deeper. Six millimeter bullets vary greatly in length, and really it's almost impossible to do the long ones and short ones without a lot of bullet jump or the bullet seated into the shoulder.
The reason I and a lot of others don't like the .243 is not the case itself so much as the shoulder design and neck length. It puts the turbulance point directly into the throat, and that's not a good thing. There's also a brass flow issue, but I think it's over hyped. Ackley improved the case, but also stated that there was much if anything to be gained from his case design except for stopping brass flow. The shoulder angle on the Winchester case is a scant 20 degrees with a neck that is about .240". On the 6mm the shoulder angle is 26 degrees ( better but not by all that much), but the neck is about .35" long. The longer neck allows better usage with bullets like the 105 grain Amax but also handles 70 grain bullets very well. I don't think I ever had the base of a bullet get into the shoulder area. Lots of folks have improved these cases in various ways, and some turned out well, and some others kinda didn't. I like the Rockchucker series as well as the Ackley.
The good old Win. .264 mag<g>! I think everyone of us has wanted one or even went so far as to build one (I almost did it twice). Do a compairson with this case an say the .270 WBY mag. Both cases are overbore, and tend to work best with heavy bullets. The shoulder angle on the winchester is 25 degrees with .254" (already too short) neck length. Once again we see the T.P. pushed forward into the throat. Should be about one third of the way into the neck from the lip. Hornaday in their manual states they went thru several barrels during load development. Now look at the Wby case design. It has a 48 degree shoulder angle with a neck that well over .300". A barrel should last much longer with the case design, and probably would be fantastic necked down to .264. (or the .257 necked up). Myself, I'd take a 6.5-06AI anyday of the week over either one in .264
The .300 Winchester really does well in the 180 to 200 grain area. After you start looking 220 grain and even 240 grain bullets it has problems. Interestingly the .308 Norma is opposite. It dosn't quite do as well as the Winchester in the lighter bullets, but does better with the heavier ones. Only thing I can see to aid it is the .06" longer neck length, and really not all that much much longer (although I think it's a better round). Like to see a short .300 WBY mag with something like a 2.65" over all case length and the same shoulder and neck.