From the ATA rule book: - and I was wrong about shot size.. I thought 8s were legal..
G. GUNS AND AMMUNITION
Any shooter violating any of these Rules shall be disqualified from
competition in accordance with these Rules. Any such violator shall be
referred to the Executive Committee for possible further disciplinary action.
A contestant cannot use:
1. A gun with a chamber larger than 12 gauge. Guns of smaller gauges are
permissible in registered and tournament shooting, but no competitive
consideration shall be given in recognition of that fact for handicap
and classification purposes. A contestant may not use a gun capable
of chambering more than one gauge of shells at the same time. For
example, chambering 12 gauge and 20 gauge shells in the same gun
at the same time is prohibited.
2. Loads that contain nickel or copper coated shot or tracer loads.
However, the use of lead, steel, bismuth, or other composite non- toxic
shot materials shall be allowed. Any gun club allowing shot materials
described in this Rule, other than lead, shall be required to cover or shield
all hard surfaces on trap fields which are known, or reasonably believed,
to cause pellet ricochet with material which will prevent the shot pellets
from rebounding and/or ricocheting.
3. Any load with a velocity greater than 1290 FPS (Feet Per Second) with
maximum shot charge of 1 1/8 ounces, or 1325 FPS with a maximum
shot charge of 1 ounce, or 1350 FPS with a maximum shot charge of 7/8
ounces or less, as measured in any individual shotshell. These velocities
are maximum and no individual shotshell shall exceed these limits for
the designated shot charge. In addition, no load containing more than
1 1/8 ounces or any shot larger than Number 7 1/2 can be used. Shot
charges are maximum and no charge may exceed the charge amount
by more than 3%. Steel shot in Number 7 will be acceptable as long as
velocity criteria are the same as for lead shot shells.
