I don't know if barrel whip or vibrations in a very thin barrel are causing inconsistant groupings? I have a 243win in a model 70 22inch Lightwt. version. The stock however is made for a 20inch barrel,it is beautiful walnut. The rifle is an older push-feed type. The stock was changed for small children length of pull. Before the stock change my loads were about .75moa , now 1.5moa same loads. I think the thin tube is whipping or shaking to much as it never was meant to free float(per Winchester) and needed the extra 2 inches of forearm.Maybe not? Several of my young hunters think the rifle is too heavy out front, so if I cut 2 or 3 inches off and target crown it should improve accuracy and solve weight problem? Also the kids dont grow into it because once they hunted they get their parents to purchase their own rifle. So far this one has been used by 6 different kids therefore it must be fixed or replaced Your thoughts please.

IMO, generally a thin/light barrel is not more inaccurate than a heavier barrel might be. A thin barrel will heat up faster, and therefore, will usually start stringing shots. Before you have the expense and hassle of having the barrel cut and recrowned maybe you should try using tape on the barrel channel about 1.5" from the end of the stock to build a slight pressure point and see if that will help stabilize the barrel. If it doesn't help you won't be out much exept a few minutes of your time and if it does you can use something more permanent. If you do try this please post the results as I am very interested in the outcome.

I'd try bedding it first. And probably with a pressure point in the forearm near the end of the barrel channel.
A shorter barrel will have a louder report and more muzzleblast. These are never good for young & inexperienced shooters. I'm assuming you've checked all the screws for proper torque. Nate

Thanks fellows , I have bedded the rec. however not enough to float the the barrel. I will try the presure points with tape and bed the forarm channel if needed. I don't really want to cut or rebarrel, so this could help. I have tried to get a better load, but not to good so far. This tells me it must be the stock as that was the only change in this normally accurate rifle, I will let you know. Ben (rug)

i think i have a similar rifle, a mod 70 243 ,blind magazine, ranger/westerner ? it"s very light, with a light profile barrel.
i tricked it out earlier this year with a supressor and a new stock, new scope, bipod etc, and started handloading for it.
i"m a traditionalist, and i love wood stocks, but here in the UK it rains a lot so i finally gave in and bought a synthetic stock so i don"t have to worry about damp swelling/warping the stock. my old stock was semi floated, with about 1 1/2" of contact at the end of the barrel channel. my new ramline stock is free floating, and i accra glassed the reciever into the stock.
the rifle is far more accurate without the suppressor, as the barrel is free to "whip" "flex" "vibrate" or whatever you want to call it. i think that as lomg as it does it consistently, it does"nt matter if the barrel is moving in the stock.
my ramline stock was cheap and cheerful, and i was a bit apprehensive initially at how flexible the forend is. i can push the barrel down into the barrel channel at the front of the forend.
to say i am now happy with my rifle now would be an understatment! it"s an old rifle, and i"m loading the bullets very long to reach the end of the burnt out throat, but boy can that thing shoot!
i"d say that if you are properly bedded, don"t be too bothered about barrel flexibility.
i"d keep trying at the load development, as i wasted a lot of lead and powder before i settled on 38 grains of BLC2 under a 100 grain
flat based bullet loaded to the max length that the mag will allow. i"ve never had as much confidence in any gun as what i have in my mod 70 with a free floating barrel.
sorry for my long winded ramblings, and i know that not all rifles will react the same to different set ups, but that"s what worked for me!
good shooting

Most of the best shooting hunting rifles I've ever owned had super thin barrels, so that may not be the problem. Moreover, many of these were acton bedded but barrel floated...