You may want to start by taking a look and compare Weatherby's TRR chambered in 30-.378 or 338-.378 vs. Sako's TRG-42 chambered in .338 lapua. The WBY 30-.378 actually has a bullet diameter of .308 but also has a larger case capacity then the .338 Lapua. (30-378 Weatherby Magnum | Norma Precision - ammunition
(338 Lapua Magnum | Norma Precision - ammunition
). This may be benificial if the right hand load could be determined, meaning: Very Fast and Flat shooting. However, given its a smaller diameter bullet; cross wind at 1000 yards and beyound could prove to be anoying. This is where the larger .338's are more advantagous in that they are of heavier wieght bullets, typically 200-300gr, thus hold over (or clicks if your a clicker) for cross wind is a lot less.
Despite the fact that the Wby .338-.378 has nearly identical ballistics as the .338 Lapua; your honest best bet is probablly the Sako TRG-42 in .338 Lapua(SAKO TRG-42
). On top of the fact that the .338 Lapua has finominal ballistics out to 1500-2000 yards and not to mention is the choice caliber for the US Marine Corp Snipers (excluding .50 cal BMG of course) and the Canadian Black Ops Snipers (Some of our Canadian snipers have confirmed kills at 2000y using the .338 Lapua); the entire gun itself is fully adjustable and has lots of add-ons. It goes for about $3000.00 CAN. Of interest; the Weatherby TRR (http://www.wholesalesports.com/onlinestore/control/category/~category_id=10110006010021/~pcategory=1011000601
) goes for about $2800.00 CAN.
For the extra $200.00 bucks I would definetly go for the Sako TRG-42 .338 Lapua. For what Sako is offering in a factory made rifle $3000.00 is more then a fair price. If you've got deeper pockets then you can always build a rifle for in and around the $6000.00-$9000.00 mark and bare in mind you haven't even put optics on yet!! In regards to features and benifits; Sako really did go all out to give you everything you need to get started in long range shooting.
Hope this helps or least points you in the right direction. Here is another awsome link that answeared a lot of my questions, this should really help you out a lot: PRACTICAL LONG-RANGE RIFLE SHOOTING - PART I: THE RIFLE & GEAR