Hello all, I am getting ready to start collecting parts for a new 7mm build. I am trying to decide which 7mm Cartridge to build. I am leaning towards the 7mm-300 Weatherby. My gunsmith here in town just built a 7mm-300Weatherby and it is an awesome shooter and performes very well. He is using 140grn Ballistic Tips and 162grn A-Max out of his rifle.
What 7mm Cartridge do you think would be best. The 7mm-300 Weatherby seems to have a little bit more velocity potential. My goal is to shoot bullets from 140 to 180grns. I would like to get your input on this matter. I am going to order my barrel first, so I am going to order a 30" 1-9 twist Krieger. Would the 1-9 twist be the right twist for the 140 and 10grn bullets?
What would the velocity potential be with the 140grn and 162grn bullets. I am thinking with a 30" barrel I could push the 140's at over 3600fps and the 162's at 3350 to 3400fps. I would aprreciate any input on this build and what 7mm cartridge you think would be best.
I've ran 160's at 3340 fps out of my 9 twist 26" lilja barreled STW, Yes I think a 9 twist will be fine, I've shot 200 gr out of my 9 twist 7mm's with good accuracy.
Doesn't matter which cartridge you go with not enough difference to really notice, I'd go with the one you can get the best brass for.
Ridge Runner, thanks for the info. If your getting 3340 fps with a 160grn bullet out of your 26" barrel, I am thinking a 30" barrel will push the 162 A-Max at 3450fps. And I am also thinking I might be able to push the 140grn BT at 3700fps. The 162grn A-Max has a BC of .625, and at 3450fps, this would be an awesome flat shooting bullet. However, I am not sure how fast the 162 A-Max can be pushed.
well not sure how they'll pan out in the long run, but I can't get the speed from my kreiger I can with lilja's, we'll see in a couple hundred more rounds and it gets broken in well, but it does shoot well. But with high BC bullets velocity isn't that big of a deal.
Since your looking at necking things anywayif it were me I'd go with a 7mmx300 Win mag Ackley improved , that will get you very close to the 7STW case capacity but in a shorter more effecient case and the ability to use Lapua brass which will allow you to run the pressures higher without killing your brass in 2 reloads.
The STW and Wby case ar so close that the differance would be negledgable.
I know a guy that has a 7mmSTW Ackley improved and he is getting 3200+fps with a 180gr Berger out of a 30" barrel and he gets 3-4 reloads from his brass.