Originally Posted by
Ridge Runner
my point is, your claiming the MV which you say you chronied, the win mag has just over 90 gr capacity, its 92% of the STW, but your getting 97% of the MV of the STW with 69 gr. of powder (or 82% of a full power stw load, which is only 76% of the case capacity, my friend I've been stuffing powder and bullets in cases since 1978, what your describing just isn't possible. burning powder gases make pressure, pressure makes velocity, you can't use less powder in a large case and make more pressure.
there are things you can do to delay throat erosion, but even a 223 will burn the throat out in about 6,000 rounds (I know this, I've probably shot out as many barrels as anyone, my 6.5 is on its third barrel and its a 270 necked down) and the 300 winny is overbore at .284, heck the 7 mag is overbore
RR
The powder speed difference between h1000 and imr4350 is dramatic. I use over 73gr of h1000 for several loads, 75 gr of retumbo for the 165-170 class. I use 83 gr of us869 on the 150s. I use far less 4350 on a much lighter bullet. I get 3425 on a 140 cutting edge with imr4350. You responded with a different caliber and different weight. Nowonder there is a difference.
I am not sure of your requirements to call a cartridge overbore. There is a series of diminishing returns with the addition of powder not resulting in an equal improvement in velocity. That makes sense to me, but with ultra slow powders like 869, what was overbore is now more efficient.
I shot this rifle at he Avenal Practical Rifle match. It was my first time using this gun at distances to 900 yards. Had my speed been off i would not have hit anything shooting 2 moa targets 1 shot only at each. So it is that fast, the bc is 590 on a 140, and i sold my 7stw when i realized this rifles potential. I thought about creating it in a 6.5, but then you hit the overbore/efficiency issue.
As for the 223, most people shoot DI guns that bring gas back into the action and shoot them quickly for multiple mags! Very few shoot three rounds and let it cool!
I have the rifle you are telling me - cant do what it does. I am enjoying it and i will smoke a big elk and deer with it this year, as long as nobody tells the elk i cant do it, that is. :-)