I've seen more than one person try that... I've also seen it damn near lead to tears when it blows an extractor, even on a fancy custom action, at a national/international level event.
One person persevered, albeit with some help. He'd shoot, another person would pick up the gun, a third would run a cleaning rod down the bore from the muzzle to knock out the fired case, then they'd put it back on the bags/front rest, and he'd line up and fire again. Rinse lather repeat. He got no end of $hit about having a crew-served weapon on the line...
If the ammo is in a cooler, best to keep an absorbent cloth of some sort between the ammo and the ice pack. *And* keep a (separate) cloth handy to wipe down the rounds before putting it in the chamber.
Basically... treat it about like if you were shooting in the rain
For F-class? You don't...
Monte; my lesson went very similar at the First SOA at Whittington in 2002.
I was shooting a factory Savage 10FP 260 using a load developed for our team by a member. It had been a hot load in testing with my gun and I had already decreased it by 1.0gr. but still seemed marginally hot. I had to ship my ammo in advance, and sent it with reservations. The day got quite hot, and I started blowing primers, and losing extractors.
But I had a couple of aces up the sleeve. I had brought a spare bolt from a 10FP 308, and we had a gunsmith attached to the team. We also had a few emergency extractors (i.e. paint can openers, with the claw on the end). So I was able to get the case out rather easily, hand the busted bolt over my shoulder and get another, working bolt, slapped into my hand. It happened several times during a couple for stages, but I still managed to get my rounds off and make respectable scores despite all the extra hustle.
It was the next day that we showed up with the ammo in the cooler. At first, it worked fine, but as the day warmed up, we were getting flyers and stiff bolts, and eventually blowing primers again. It was a WTF moment. Then we noticed the condensation on the rounds after they were out of the cooler or a couple of minutes.
Taking a chance, we started wiping down the rounds with a shop cloth before inserting the rounds into the action, and the problem was identified and solved on the spot. Getting the round off quicker seemed to help as well. Good thing we had the collected brains of Team SH, or I'd have gone home a sad boy that week.
It only happened with my rifle despite it being one of three or four from the factory with consecutive serial numbers (this was the Ghost Dancer Project at work). We never got it nailed down why mine was the oddball; but within a year I had a new 28" L-W barrel installed and it works fine now. As I understand it, Mike Duncan ended up with my old one.
My guess is that the headspace was a bit tighter with mine.
---------------------------------------------------------------------------------
At my last serious match (2017 Berger SW LR Nationals at Ben Avery Range), I shot only the MR 600 F T/R stage using a 223; but this comment is about the 284. I scored for my squadded partner, who was shooting a custom built .284 Win (175's?). I scored him a perfect round, all X's for one of the two stages we shot together. I think he managed 12 or 13 straight, so course, according to the rules, we kept going until he dropped an X.
So the 284 has the performance, and I'd consider it an excellent choice for F Open.
With regard to velocity; it's really not such a big selling point, IMHO. As Long as the round reaches the target at a velocity above transsonic (I like a 1300fps speed at target), you're going to do fine; and what imagined advantage in wind deflection may exist, its value is buried down in the 'white noise' of deviations that also accompanies each individual shot.
It's not all just about the wind.
Note also that altitude is a big factor, since higher altitude allows a (sometimes significantly) higher speed at the target from the same equipment setup than at sea level. At my altitude of 4350ft, the difference is definitely significant. I'm getting away from the heaviest bullets and VLD designs; because at my altitude, I'm still beating their sea level performance with more conventional projectiles.
Greg