John,
If I were you I would go with the Warbird. The .30-378 is nice, but there is a belt, there is the venturi shoulder. Brass for both is very good. I have heard of Lazzeroni brass being reloaded over 20 times. I think Warren told me that with a 29" barrel he could get 3300 fps from a 30-378 with a 220 grain bullet. I would assume that the since Lazz case is a tiny bit smaller that with a 30" barrel you could get about 3300 or 3350. If it were me I could get the Warbird using 220 grain bullets with a 1:8 twist. That isn't necessarily an MK, but a J40 Warren says that would be best. I'm not sure what grain bullet you want to use, but with a case that big I would go with a 220 grain J40 or MK or the 240 MK. I agree with Jerry about accuracy. I can get 1/4" groups at 100 yards with a 220 MK. I could think that a 30" barrel and one of these cases your velocity would be about 3600 or more, then your accuracy might go down. One more thing, I would go with the PGW action since the M700 might be a little "weak" for cases of that size.I hope some of this helps.
[ 01-04-2003: Message edited by: Nighthawk ]