I don’t agree with this.
I have hunted all of my life and have always been considered a good shot.
I started benchrest shooting 1+ years ago. It is totally different. There is a learning curve involved in figuring out how to get the most accuracy out of a gun while shooting from a bench.
All benches are not equal. Bag set up is critical. Rest setup is critical. Consistent gun handling technique is critical.
After you get those things figured out, you still have to learn how to load top benchrest quality loads. Easy? For an elite few maybe. For most it seems this is easier said than done. Get that figured out and your move to the next hurdle.
You then have to figure out how to tune the load-for the gun on that day. Right bullet for right gun with right powder etc...
You are ready now to shoot the potential out of your gun. NOT!
There is this little thing that you can not see as you sit at your perfect bench with your perfect setup-WIND.
I guess you see my perspective about this, don’t you Alice.
Welcome to the trip down the rabbit hole.
Good comment. I was not speaking about competitive BR shooting, and I am on my sixth active season of LR/BR (2005-2007 and 2018 to present). The OPs question looked to be more about shooting his rifles well off the bench, not BR competition. My statement is correct under those circumstances. It does not take a refined BR shooter's skills to shoot even very accurate hunting rifles and target rifles with non-BR level accuracy requirements to their potential off the bench.
Like you I hunted and reloaded for years before I jumped into BR. That is where I learned how well rifles of various kinds would shoot. I became anal about accuracy in a hunting rifle. I would work to find the most accurate
hunting bullet and load. Shooting with a protector rear sandbag and a Hoppes front rest I got several heavier barreled hunting rifles, factory and custom, to shoot 1/2 to 5/8 MOA at 100-200 yds. Rifles with sporter weight barrels were 5/8 - 3/4 MOA. These were not benchrest prepped loads. All I did was weight sort the cases and bump the shoulder .002" when sizing.
In the years since I first started LR BR I have worked up many big game rifles, from .270 to 450 NE. I don't shoot them any better now than I did 20+ years ago even when I use more of my good BR loading and shooting techniques. As long as the rifle is stable on the rest when you smoothly squeeze the trigger, and you are consistent with sight alignment, you will shoot most rifles as well as they are capable of being shot off a bench. I have showed others how to do this.
In just one range session I had my very inexperienced son-in-law shooting his 375 H&H into one-MOA groups. This was the first time he had ever shot anything larger than a .270. That was as good as that rifle would shoot that load--I know because I worked up that load. All it took was showing him how to get comfortable and stable on a reasonable (but not high end) rest set-up. Others I know have taken people who have never shot LR BR, put them behind a well-tuned load, and had the newby shoot the rifle very competitively.
Now if we are going to talk about what it takes to be competitive at BR, whether long range or short range (which are entirely different), we are talking about learning a sport. That is very different than the gist of the original question, which was the OP wondering if he was just a bad shooter or he had bad rifles.
Since he has now shown the group sizes it appears he is really asking a different question, which seems to be "how do I get my non-BR rifles to shoot short range BR groups." My answer to that is it is very tough, as even a well-tuned LR BR rifle that can shoot under 1" at 600 and under 3" at 1000 won't keep up with a short range BR rifle, micro-tuned on match day, at short range.