Thread: Keeping the 7mm ahead of the 30 cal?

Originally Posted by Greg Duley

Andrew, you cannot get 3471 fps with a 180gn Berger out of 30 inch barrels RUM without out blowing cases. Either your chronograph is inaccurate, or you're talking BS. The Nosler RUM brass you were using won't take anymore than 65,000 psi without popping primers. A 30" RUM at just under primer popping pressure will push a 180gn at 3400fps max. We built your rifle, and many like it, and have strain gauges on enough of them to know exactly what they will do. Do not try and reach Andrew's claimed velocity or you will end up with molten brass in your eye at the very least!
Also, the only 180gn Berger that will stand 3400fps with accuracy is the Hybrid. Don't waist your time with the VLD's.
As Kiwi Greg and Don say, it depends on what you're trying to achieve. If you want the absolute best long range performance in the wind, with minimal recoil, in the lightest possible walkabout hunting rifle, then this new bullet with a projected .400 plus G7 BC may well be superb in our biggest fast twist 7mm's. The barrel life will be reasonably short in the likes of our 7mmSF or Kirby's 7mm AM, but as a specialist long range lightweight hunting rifle, who cares! If you can handle more rifle weight and recoil, then the biggest 338's will beat it in barrel life and killing performance for sure, but it will need to be a big, long barreled 338 to beat it ballistically for drop and windage. At the very least a 338/416 imp like our 338 Thor, or a 338 Cheytac imp like our 338 Lunatic. An Edge, Lapua, or Lapua AI won't touch it. The 375 Cheytac imp, if the new bullets/twists all work out, certainly will beat it and the big 338's. But in a lightweight hunting rifle, I shot and killed a lot of deer with the 7mm 200gn Wildcat bullet (until Richard sold the business), and know exactly what a really big 7mm can do! Bring it on!

Greg

The trouble with any extreme over bore case like the very big 7mms when you talk about barrel life isn't just that its short its that they are sometimes very hard to keep tuned with the best BC bullet on offer for the entire short life of the barrel. Often you have to go to another lower BC bullet to keep it shooting after just half of the short barrel life, yes the barrel is still shooting but the best BC bullet can no longer be used so greatly changing the great ballistics it once had. Kerby had this happen to his 7mm Allen mag having to change from the 200gr wildcat to the 160gr AB, I am in no way saying that the Berger 195gr want be a great bullet but you may have trouble keeping it shooting in the big 7mms, now the target guys who don't need to push it hard to get expansion at long range will be very interested in this bullet in a medium case as a great windy day bullet.