Always interested to read your test results, good stuff. In my 1-7 Lilja 3 groove I can load both the 100 and 107 gr ULD RBBT to right at 3100 fps with fine accuracy. At 100 yards I was getting one hole groups consistantly at this level. Only bad thing is that in this case capacity, pressure is so low that bore fouling is misserable as you can imagine with the powders needed.
This 3100 fps is the ragged edge for these bullets as even a boost to 3125 fps tears them apart.
I tested these bullets in a 1-8 3 groove as well thinking maybe I was over spinning them and causing the problems. This test was out of a 22-6mm AI chambering. This twist rate did not stabilize these bullets at any load level.
Interestingly enough, I pulled my original 224 AM test barrel, cut the chamber off and rechambered it to 22-250 AI. Using Ramshot Magnum powder I can load it up to its upper velocity range(3100 fps) in the 24" barrel with good working pressure and amaxing accuracy. I was getting around 1/5 moa groups at 500 yards with this rifle and its based on a Ruger M77 Varminter if you can believe it. Untrued and all.
Used it to take this nice Fallow this spring at 310 yards
Bullet performance was not much as the meplates were closed almost to pin points in the attempt to get the highest BC possible and also because there were designed to be used on coyotes to limit pent damage, not for big game use. But it expanded enough to get the job done very cleanly.
Persoanlly, I would very much like a heavy jacketed 110 gr ULD Flat Base bullet for my 224 AM. With a meplate opened slightly for medium game hunting performance. I think it would be a heck of a bullet and in the 224 AM in 26" barrels I think it would be able to reach 3400 fps pretty easily and still have a BC well above anything else offered by commerical bullet makers.
Your 257 issues sound very familiar to mine dealing with my 257 Allen Xpress and 257 Allen Magnum wildcats. The 156 gr ULD RBBT has a pretty heavy jacket on it and handles the 1-7 twists pretty well as long as the barrels are not overly hot or long in the tooth.
The 142 gr ULD RBBT is based on the much thinner J-4 and really needs a 1-8 or even 1-9 6 groove for best results.
The Nosler bullets have an extremely heavy jacket by comparision and a very heavy solid base as well so they will handle pretty much anything you throw at them.
Now if Nosler would make a 100 gr 22 cal accubond, I would be happy as could be with my 224 Allen Magnum. THink that will happen any time soon????
Good reports, thanks for the data. Let us know what velocity you are getting when you get your chrono back up and running.