Originally Posted by Derek M.
Are you talking for a WSM or do you have the 270 AM? If the latter, what powder are you using?
I have one and just have not had time to play with it as much as I'd like. I have 500 of the Wildcat 169.5s and almost 16 pounds of WC872.
I have both the Win and Allen Mag.
If the 169.5s are from Richard Graves they will most probably be the goto bullet. They will out do the Matrix in every case, unless your rifle simple doesn't like them
My sincere recommendation is to break it in. (zero and load development as much as practicable during break in) Don't waste any shots during drop chart development. The key is conserve barrel live!
You have enough bullets and powder for a couple of life time, if, the rig is used as intended. A long range animal harvesting machine.
I use 869 for 169.5s (99 gr) also for the 195s (91 gr) WC 872 was the "designed for" powder but a lower load densities it burns like an old time locomotive under heavy load.
Be cautious of [powder bridging] which is a real eye opener! Stay away from using any course stick powder and heavy bullets. I did and it was not good!
US-869 is too slow, but from recent reports of changes in Retumbo and H-1000, it may be faster than it was, for 150 class bullets. Load got to the point where pressure did not increase and velocity did not increase with the light bullets as powder was increased. Noise was was more impressive though.
I use 7828ssc for 140 and 150 Noslers. Absolutely great velocity and accuracy. Poor bc though.
I'll try the 160 grain projectiles with ssc and 869 this spring.
I have over 900 rounds through mine and is still going strong. I've done way to much messing around with it but its is such a pleasure to shoot.
Also, I believe mine was one of the first several. Its a shooter alright but I think subsequent throats were better or at least different in some way.