My experience with .224 to .30-06 sabots
My wife decided she wanted to get a rifle and wanted it to be a one gun for everything rifle. We decided on .30-06 and figured it would be good for anything in North America, but obviously iffy on coastal browns. In order to open up her opportunities for hunting we decided to try it for small game with some .224 bullets and sabots. Remington used to manufacture ammo like this and called it "Accelerator" ammo.
I ordered the sabots from EABCO and paired them up with some 55 grain Sierra Gameking bullets. The loading info from EABCO recommended IMR 3031 and said 57 grains would yield 4200 fps. I loaded up three rounds each of 55, 56, and 57 grains.
To say I was unimpressed is an understatement. I know that there's no way this can be as accurate as a gun designed to shoot .224 bullets but muzzleloaders shoot sabots into a 2" group at 100 yards so I expected something close. Her gun is a Remington Mountain Rifle and is capable of 1" at 100 yards with 110 grain FMJ and 180 grain Barnes TSX. Out of the nine bullets only 5 hit a 12" x 12" piece of paper. They didn't even group and were scattered all over the paper for all three loads.
I'd like to hear if anyone else has tried these sabots or shot Remington's Accelerator ammo.
When it first came out I shot the Accelerators in 308 and 30-06. My 308 had a 1:12 twist and did 1.5-2" groups. Okay, but not good enough for the ground squirrels we were shooting at the time. The 06 I tried them in had a 1:10 twist, and groups started okay at around 2" for three shots, but by the time I finished the box they were up to 6" or worse. I wrote that off to bad plastic fouling, but never experimented to prove it.
I'm betting that the plastics are better today, so the next guess for your situation would be bullet length. Check the twist on your rifle, then compare that with twists for standard 224 rifles at similar velocities. I'm betting that if you adjust bullet length for the optimum you see there, you might improve things.
Another unresolved issue for me was the huge jump between the bullet and lands.
I gave up and went to the 110gr Speer HPs in both rifles. I found loads in each that would break an inch more often than not, and they vaporized the squirrels.
Another side note--- For plinking with her 06 my wife is wildly happy with 125 grain Sierras on top of enough 4320 to drive them to 2500 fps. Milder than a 30-30, and probably the most accurate load going in her rifle. She's whapped a few deer with it too inside 200 yards, and results were excellent.