The Berger rep is giving you just a partial portion of the actual trueth without qualifying his comments. Let me see if I can explain his points a bit.
I would agree with him that these bullets are on the ragged edge of staying together but this is not because of the velocity or pressure, its because of the jump into the lands which is tearing the bullets jackets free of the lead core. Nothing more nothing less. If you seated the bullets 5 thou into the lands your problem I am sure would go away until you get to the 3200-3250 fps range. After this accuracy will generally start to suffer.
In my opinion, dropping 1/2 grain will not amount to Jack Squat in a case the size of the 30-378, bad advice in my opinion, will not help your problem.
As far as the freebore in the Wby rifles. This is not a safety issue. It is a chambering method which flattens the initital pressure spike when a round is fired in the rifle. It does this because the bullet gains velocity before it hits the origins of the rifling. Because the bullet has gained significant velocity, there is less resistance when the bullet encounters and is engraved by the rifling. Thus it will lower chamber pressure and flatten the pressure spike.
This allows you to do several things, mainly, add more powder to your charge without increasing pressure significantly.
This is why if you take a factory rifle chambered in say 30-378 and compare it to a short throated custom rifle
in 30-378, the Wby rifle will generally produce significantly more velocity for a given barrel length.
Simply put, you are correct, Weatherbys claim to fame was hyper velocity in those early days. He got this and kept pressures in a high but usible range by freeboring his chambers. It is an attempt to get every last fps of velocity possible out of a given cartridge but often at the expense of accuracy.
As to getting higher velocity with the bullets seated closer to the lands. This is true to a point. If you take a given max load developed with the bullet 0.200" off the lands you will get X PSI of pressure. If you take that same load but now seat the bullet so that it is touching the lands, pressure will increase dramatically because the freebore situation has been removed.
That comment is concerned with using the same load for both seating depths.
TO more accurately discribe things, if you take one seating depth, say 0.200" off the lands again, and develope the load to max pressures you will get X fps.
Now if you take a seating depth of say touching the lands and work that load up to the same max pressure as the previous freebore load, Your top velocity will be lower simply because your pressure spike will be steeper and you will reach max pressures sooner then you will with a freebore situation.
So while there is some trueth to his comments, they are really only half trueths.
On average, freebore will increase top possible velocity but again generally at the expense of accuracy.
One other tip to remember, when using a heavy thin jacketed bullet. The farther away from the lands you seat the bullet, the harder it is on the bullet to survive the launch. The closer the bullet is seated into the lands the easier it is on the bullet.
The reason is simple, if a thin jacketed bullet is seated to touch or even softly into the lands, when it is fired, it will begin rotating the second it begins to travel down the barrel. This basically eliminates the "Wringing" of the bullet and it will survive much higher launch velocities.
Good Shooting, hope this murkies the waters even more!! [img]/ubbthreads/images/graemlins/grin.gif[/img]