One of our sabot testers with tight barrel, Abolt, with wide lands in
the barrel, who couldn't do any good at all with our sabot and Alliant Steel
and one type of slug, had to go to IMR 4759.
It would twist up the sabot petals. Terrible accuracy.

My guns have NEF/Sav size barrels and worked fine with Steel as well as 4759.
Petals open perfect. The Abolt barrel is about .005" smaller than NEF/Sav and
the lands over twice as wide as the NEF. And has real narrow grooves.
Guys with Nefs say sabots open fine like ours here.

He went to different Minie slug and our slow powder loads using
IMR 4759 powder up to 78-79 gr and finally got down to 2.5" group, I told him
go to max which is about 80-82 in 3" case.That barrel is like a lot of
EU made barrels and many are replacement or add on barrels in many slug guns,
and that is reason why it is so hard to get accuracy across the board in
sabot shooting in all guns--Takes a lot of work.. Another tester with NEF 12ga using
Alliant Steel with sabots got good groups like we did here. I tell guys if
problems occur go to 4759.

What was happening to sabot petals in the barrel, with the extra tight fit and
wide lands were petals twisting.. The wide lands were not cutting into the base of
sabot like in NEF/Sav210 barrels. The twist effect of rifling was on the surface
of petals, twisting them. It was not getting good hold on the sabot body. The
4759 starting slower allowed the sabot to get its spin started up to speed
with the wide land rifling and narrow grooves..It is just the opposite of
way NEF/Sav 12ga barrels are done. with narrow lands which impress into
the sabot base the way it is supposed to work..I showed pics above of the
good rifling marks impressed into our sabots.

I think after this experimenting run I feel that a lot of accuracy problems
across the spectrum of barrels are due to barrel differences, and not just
the differences in factory slugs and/or reloading components.

Here is pic of bag of our 585 cases with plain head if some need them for
wildcatting.We have quite a few. Fifteen have 585HE cases now. 585 gun
building is accelerating. We can get folks going with 100 cases, dies, and soon
a barrel; and shipping, for 750...Ed