Yeah, well don't forget to tell her that you asked for it!
Maybe the only consideration here is similiar to an oily or slightly wet bore, from the bench. Might open up the group, slightly, might not?
But, driving a bullet through a driving rain after it has left the barrel is probably more of a challenge, than the wet bore?
I've hunted in rain before, and my only consideration was rain drops on the ocular lens. The visibility in general is so restricted because of the sparkle, looking through the scope. Once it really starts coming down, most of your quarry is seeking shelter, anyway. But, I'm a firm believer in subjecting the rifle to the elements it has to operate in. I wouldn't keep it in a hermetically sealed case, and pop it open on the spot.
We used to get a plastic cap that slid over the flashguard, back in my war hero days, but holding your rifle with the barrel down is just as effective, if you don't have one handy.
Just do the best you can with what you have, and don't worry about it.
Hunting in the wooly north, I will share my thoughts.
Electrical tape over the muzzle - must do.
Keep rifle outside if temp is cold. This ensures you don't get thermal shock, better known as fogging when you take it outside. do check your action screws because going from hot to cold several times may cause the stock to move enough for the screws to loosen.
If you wear glasses and are truck hunting, wind down the windows to keep the cabin temp relatively cool. Nothing more frustrating then stepping out of a warm cab and having your glasses or scope fog up then freeze. That would be good for America's funniest videos.
Avoid stocks that are unstable in varying temps/moisture. Some walnut stocks are stable, most are not. Lam or composite.
With the action closed and muzzle taped, condensation is not going to collect in the bore unless you are in West Coast rain, also known as underwater.
If you are stuck in a downpour, keep the rifle level or muzzle UP. Because your muzzle is taped, the concern is water getting into the action/chamber. With the muzzle level to up, water will run out the trigger group. Another good reason to have synthetic lube on your trigger group. Keeps things from rusting and freezing.
I use synthetic oils and lubes. They don't freeze or thicken in temps I am ever going to hunt in - that still gets pretty damn cold.
For lense fogging, consider the Elite 4200 scopes. The Rainguard is supposed to work.
Good luck with the hunt and hopefully you will have decent weather.
Len, an educated guess says you'll be in a warm dry pick up cab most of the time. I don't think you need to worry too much about the rain. However if the roads turn to gumbo that may put a serious damper on things. Oh and btw a pard of mine killed one of the bucks I've been watching and video taping. He got it with his bow last week less than 20 miles from here. It grossed 189 and nets 183. Like I said there are definitely some big bucks around this year.
A Marine friend told me about the electrical tape a number of years ago. I wondered if it would affect the accuracy and change POI so I shot some groups with it on----no change. Now I don't have to worry about rain, snow, dust, dirt, pine needles, twigs, etc........ I've never found any moisture in the barrel after a wet hunt either. And it's cheap!
Yes... The RainGuard works great but the reticle adjustment on the 4200's leaves a good bit to be desired (inconsistent) and they have an incredibly small amount of total adjustment available.
Therefore I use the Mil-Dot models and don't adjust the reticle AT ALL when I'm "in the field".
Oh yeah... And I use the Burris Zee Signature rings with offset inserts to position them dead center, with crosshairs at mechanical center, at 100yds with a good bit of elevation available (front of scope tilted down a bit).
Zero is typically at 3-400yds with a 300WSM and 2-300 with my 308's.
If it's long it can't be wrong... LDHunter (Long Distance Hunter) from the Piney Woods of NW Florida. I hunt clearcuts for scrawny whitetails... ;)