Good evening Paul,
Weathers looking better for the 800 tomorrow, but the NW wind will be fishtailing again.
About calibres, I'd just as soon have a chat about it so people know why it is your favourite. In fact I'll get it started now

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Ever since owning a .264 Magnum in about 1970, I've had a soft spot for 6.5mm. When I returned to shooting after an 18 year spell, and was told about F-Class Open, it had to be a 6.5. Then I read somewhere that the 6.5x284 was winning a swag of long-range shoots in the US, so that became the one. I now think that there is probably a slightly better choice in 6.5, something that will still safely push a 140gr projectile at 2950fps, but with a longer neck and less case capacity. The 6.5x55AI seems to come closest.
But 6.5mm is a great all-round choice if you have just one rifle in F-Open. There is one group starting to prefer 6mm, and another raving about 7mm. That suggests that 6.5 must be pretty close to the ideal

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Barrel life can be a concern, but when you work it out, the additional cost of a 1500 round barrel over a 3000 round barrel is about 25 cents a shot, or about $6 per Saturday. Its worth it

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Alan