Hi,
I had this same issue with my daughter many years ago, and then again with her oldest son just before he turned 5. Yea I know 5 might be a bit young, but in our family we have all hunted from the time we knew what "Shhh there's a deer" meant. That said all the kids in our family have been out in stands as young as 2 or 3 and gone from there. Yea it tool patients and blowing a few hunts but the excitment they got from it and the yearing to do their part has been worth it.
Each child is an individual unto their own. Some have the upper body strength to handle a rifle with a rest of course, and some simply do not. With my grandson just fixing to hit 5 he boldly stated he wanted to shoot him self a boar hog for his birthday. Well this put the heat on as I had only a couple of rifles capable of doing this with out knocking him on his keister. So, I drug three of them out two being 243's and the last being a Ruger compact in .308. Bear in mind I had already looked over the load data as well as factory offereings in reduced loads. Well after all was said and done the .308 won out as he could at least manage to hold it up, work the action and the rigger and safety was all within easy reach for him.
We practiced many times over the summer to get him where I thought he needed to be and on his first weekend trip to the stand, he put a stinking 150# boar on it's ear with one shot. This was two weeks before his 5th birthday. THe deal was he had hold the rifle and all I was to do was help him get into position, and tell him when to shoot. He had on my peltor muffs which allowed me to whisper what I needed him to do and when to take the shot. He held the rifle while perched on my knee in order to be high enough to see over the rail of the stand.
With the reduced loads the recoil when using the 125 - 135gr bullets is minimal. THe best part is you can use the same powder to creep the loads up so that they hardly notice any increase at all between a month or so of shooting. For practice loads we use Remington 125gr JSP's and for hunting loads I switch gears and up the charge just a bit for the Barnes 130 TSX. He is shooting close to 2650 fps from the little Ruger with the hunting loads and can group them around 1" at 100yds and has done as well out further but I limit his hunting ranges to around 50 - 75. So far he has three hogs, and a yote he took cleanly at 158yds, to his credit. He just turned 6 this past Thanksgiving and keeps me working to keep him in ammo.
As for the rifle, fully loaded, topped with a 1.5x6 Burris scope it comes in at 6.5lbs. Nothing else I have comes in under 8 so he has a while to go before swapping rifles but with the .308 he should be able to just keep upping the load and using it for the rest of his days or till he decides to purchase something else on his own. I purchased the rifle for myself but seems he has taken over possession and sometimes he allows me to take it out for a spin. I have taken many feral hogs with it since I got it years ago when they first came out. I wished now I had picked up a couple of them. I have made clean one shot kills out past 400yds with it using factory Rem Core Lokts on numerious occaisions. However these were on hogs. The little thing has only had a few deer in the scope and I wasn't behind the trigger and they didn't offer the proper shot for him.
Good luck with your daughter, and what ever you decide on be sure to check the Hodgdon Site for the Youth Loads. THey work very well for the shorter ranges and very little recoil.
Feel free to look over the above mentioned shot on the hog, and anything else in the albums at the link below.
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