I tried using IMR 4064 all the way up and down the powder recommendations using a hornady 95 grain SST bullet. I could not not get it to group at all. The best was in the 2 to 3 inch group at 100 yards. I can grab this rifle a weatherby 243 and a cheap box of hornday whitetail 100 grain soft point and shot sub moa all day with it. So I know its not the scope or the rifle. I am using good new brass and I have prepped it very well also federal match primers. I have about 300 rounds of the SST bullets that I would like to shoot at a low or medium velocity to let my 9 year old son deer hunt with. I am seeking any power recommendations you might have for a 95 grain SST bullet in 243. My go to powder is usually IMR 4064 as this is the first time I could not get it to work. I dont like stocking alot of powders but I have several pounds of H1000, W748, IMR 4198, CFE BLackout all of which im sure are not right for a 243. I have a small amount of H4895 that I could try. Any input please????