Have you tried a lighter accubond or just the 200gr?The tsx is also worth trying as they seem to shoot very accurately out of most rifles.

I think maybe you have not found the right load. Try Hornady 180 gr. Innerlock bullets they havegrouped well for me. Also try match grade primers, andturning your necks.Try to make each case exactly alike.Good luck.

I have tried the 180 and the 200 grain accubond. I would like to stick with nosler bullets because they have performed very well on game for me. I will try the match grade primers and neck turning next I guess.

I took it to a gun smith and he found that the crown on the inside of the barrel has gotton dinged up some how. He is going to re- crown it

I have a Savage 12 in 223 that will shoot .50 groups frequently with sierra bullets and will do .75 with hornady match and nosler match. But load a 60 gr nosler partition and crap is what you get, 1.75- 2.25 is as good as it'll do.Been trying to get my son-in-law to take them, but his Ruger twist to slow for a 60 gr bullet. My Savage 270 will not group better than 1.5 with Nosler ballistic tips but will do better than 1" with hornady sst's and gamekings. My point is ,you need to try more different brands of bullets before you start screwing arround with your beding or anything else.The number of .308 bullets available is huge. Also you only named two brands of powder, did you try less than maximum loads ! I've noticed my best groups tend to come from a canister with the Hodgdon name on the label. Also and this might be the most important, shoot you group with all first shot rounds( when hunting it's the first shot that counts) wait 20-30 mins between shots,and possiably run a patch thru your bore between them as well. You will likely be hunting with a clean barrel , so why not know where it's going to place the first shot. After the first one he will be running anyway,if you miss, and a tight group will not help much then.

I have a Browning Micro Hunter in 7-08 that shot terribly (2 - 2 1/2") 5 shot groups. I tried at least a half dozen different bullets with different powders, charges, and primers. I liked the rifle but after about 6 months of tinkering with it and not getting it to shoot, I took it to the local smith and had it rebedded. He told me he had to do quite a bit of work on it to get it "right". I took it back out several times since then and it is shooting right around 1" groups now using Hornady 139 gr BTSPs.
But before you go and get it bedded you may want to be sure you need it.
Some Reloading tips to insure accurate loads that I use is after sizing, I always trim my cases even if I just touch the case mouth. This trues up the mouth of the case, then chamfer and deburr it. I use a hand primer (RCBS). When I seat the primer, I rotate the case 180 degrees and seat again ensuring it is seated squarely in the primer pocket just below the case head. I also use a Lee Factory Crimp die after bullet seating to give me a uniform starting pressure. There are some theories out there that say that this also aligns the bullet to the bore better. I'm not sure of that but I do notice a difference in accuracy with and without a crimp in several cartridges I load.
I don't know how much you have shot or your experience but a few tips. Take it out and take care to be consistant with your shooting technique. By that I mean be sure you place the rifle on the rest the same, consistant shot to shot cheek pressure on the stock, be comfortable using as little muscle tension as possible, trigger squeeze, etc. It may even be that that 300 is walloping you a bit too much and you're anticipating the shot and unconsciously flinching a bit. Try using a recoil pad on your shoulder of even folding up a hunting sock and sliding it under your shirt to absorb some of that recoil. And, I agree with Bigcountry - a five shot group is better than a 3 shot group for determining a rifle's accuracy. IMO 3 shot groups are for sighting in purposes. Let us know your outcome.

Well I got the gun back from the smith. He had to shorten the barrel about 1/4" to recrown it. He also did some bedding work. It now shoots 1/2" groups with 200 grain Nosler Accubonds. So I'm stoked!

what did the re-crown cost?

my brand new 22-250 does that too. 2 solid shots and 1 pushes my group from dime size to 1".
i did try a 5 shot group and 4 were nickel size and there was the 1 messing up my paper. would i be able to identify the nesessity for a re-crowning? (visible signs)

les

It costed $50.00 for the crown job and $30.00 for the glass bed. Mine had visible signs of damage to the crown but I would get a gun smiths opinion before I did anything.

You know I had this problem to with my first 300RUM 700 BDL. For the life of me, I can't understand how a company could mess up making a crown. but they did on mine, and sounds like yours.

Glad you got it resolved.